0.2.160

docs/about.md

@@ -31,15 +31,15 @@ Just like Arduino, the micro:bit can be connected to and interact with sensors,
 
 ## Blocks or JavaScript
 
-The student can program the BBC micro:bit using [visual blocks](http://www.github.com/Google/blockly) or JavaScript.
+The student can program the BBC micro:bit using Blocks or JavaScript.
 
 ```blocks
-basic.showString("BBC micro:bit!");
+basic.showString("Hi!");
 ```
 
 ## Compile and Flash
 
-When a user has her code ready, she can connect her BBC micro:bit to a computer via a USB cable, so it appears as a mounted drive.
+When a user has her code ready, she can connect her BBC micro:bit to a computer via a USB cable, so it appears as a mounted drive (named MICROBIT). 
 
 Compilation to the ARM thumb machine code happens in the browser.
 
@@ -47,6 +47,7 @@ The student is prompted to save the ARM binary program to a file, which she then
 which flashes the micro:bit device with the new program.
 
 ## Simulator: Test Your Code
+
 Before a student compiles her code for the micro:bit, she can run it using the micro:bit simulator, all within the confines of a web browser. 
 The simulator has support for the LED screen, buttons, as well as compass, accelerometer, and digital I/O pins.
 
@@ -54,5 +55,10 @@ The simulator has support for the LED screen, buttons, as well as compass, accel
 
 The [C++ BBC micro:bit runtime](http://lancaster-university.github.io/microbit-docs/), created at [Lancaster University](http://www.lancaster.ac.uk/), provides access to the hardware functions of the micro:bit, 
 as well as a set of helper functions (such as displaying a number/image/string on the LED screen). 
+
 The JavaScript micro:bit library mirrors the functions of the C++ library. 
 When code is compiled to ARM machine code, the calls to JavaScript micro:bit functions are replaced with calls to the corresponding C++ functions.
+
+## Open Source
+
+The editor for the BBC micro:bit is [open source](/open-source) on GitHub. Contributors are welcome!

docs/device.md

@@ -15,12 +15,14 @@ It flashes yellow when the system wants to tell the user that something has happ
 ### Buttons
 
 Buttons A and B are a form of input.  When you press a button, it completes an electrical circuit. 
-The micro:bit can detect either of its two buttons being pressed and un-pressed and be programmed 
-to act on that or send the information to another device.
+The micro:bit can detect either of its two buttons being pressed/released and be programmed 
+to act on these events.
 
 Button R on the back of the micro:bit is a system button. It has different uses. 
 When you have downloaded and run your code onto your micro:bit, press Button R to restart and run your program from the beginning.
 
+### USB connection
+
 When you plug in your micro:bit, it should appear as MICROBIT. 
 If you accidentally hold down the reset button as you’re plugging in your micro:bit, 
 the micro:bit will appear as a MAINTENANCE drive instead of MICROBIT. This is known as maintenance mode.**
@@ -43,7 +45,7 @@ This data can be used by the micro:bit in a program or be sent to another device
 
 ### Accelerometer
 
-There is a an accelerometer on your micro:bit which detects changes in the micro:bit’s speed. 
+There is an accelerometer on your micro:bit which detects changes in the micro:bit’s speed. 
 It converts analogue information into digital form that can be used in micro:bit programs. 
 Output is in milli-g. The device will also detect a small number of standard actions e.g. shake, tilt and free-fall.
 
@@ -75,7 +77,7 @@ The BBC micro:bit can send an receive data via [serial communication](/device/se
 
 ### Bluetooth Low Energy (BLE) Antenna
 
-You will see the label BLE ANNTENA on the back of your micro:bit. It is for a messaging service, 
+You will see the label BLE ANTENNA on the back of your micro:bit. It is for a messaging service, 
 so that devices can talk to each other. The micro:bit is a peripheral 
 device which can talk to a central device like a smart phone or tablet that has Bluetooth Low Energy (BLE). 
 The micro:bit can send signals and receive signals from a central device so another BLE device can 

docs/device/contents.md

@@ -1,7 +1,5 @@
 # micro:bit - the device
 
-The micro:bit device
-
 The micro:bit is a very capable device with many components:
 
 * [the USB connector](/device/usb)

docs/device/crocodile-clips.md

@@ -11,12 +11,6 @@ This example displays a random number every time the crocodile clip holds  `GND`
 
 ### Connecting Crocodile Clips
 
-
-
-### Lessons
-
-[love meter](/lessons/love-meter)
-
 ### See also
 
 [micro:bit pins](/device/pins), [pin is pressed](/reference/input/pin-is-pressed), [analog read pin](/reference/pins/analog-read-pin), [analog write pin](/reference/pins/analog-write-pin), [digital read pin](/reference/pins/digital-read-pin), [digital write pin](/reference/pins/digital-write-pin)

docs/device/reactive.md

@@ -1,7 +1,5 @@
 # The micro:bit - a reactive system
 
-The micro:bit is a reactive system.
-
 ### Computing systems
 
 What sort of a *computing system* is the micro:bit?

docs/device/screen.md

@@ -3,7 +3,13 @@
 The micro:bit LED screen 
 
 ```sim
-basic.showString(" ");
+    basic.showLeds(`
+        # . # . #
+        . # . # .
+        # . # . #
+        . # . # .
+        # . # . #
+        `);
 ```
 
 The micro:bit LED screen consists of 25 red LED lights arranged in a 5X5 grid (5 LEDs across by 5 LEDs down).
@@ -14,15 +20,15 @@ You use ``x , y`` coordinates to specify a particular LED in the grid; where ``x
 
 Here are the x, y coordinates for the LEDs in the 5X5 grid:
 
-`0, 0` `1, 0` `2, 0` `3, 0` `4, 0`
+`(0,0)` `(1,0)` `(2,0)` `(3,0)` `(4,0)`
 
-`0, 1` `1, 1` `2, 1` `3, 1` `4, 1`
+`(0,1)` `(1,1)` `(2,1)` `(3,1)` `(4,1)`
 
-`0, 2` `1, 2` `2, 2` `3, 2` `4, 2`
+`(0,2)` `(1,2)` `(2,2)` `(3,2)` `(4,2)`
 
-`0, 3` `1, 3` `2, 3` `3, 3` `4, 3`
+`(0,3)` `(1,3)` `(2,3)` `(3,3)` `(4,3)`
 
-`0, 4` `1, 4` `2, 4` `3, 4` `4, 4`
+`(0,4)` `(1,4)` `(2,4)` `(3,4)` `(4,4)`
 
 The x, y coordinates for the LED in the centre of the grid are `2, 2`. Starting from `0, 0` count over 2 columns and then down 2 rows.
 
@@ -35,7 +41,8 @@ Since the row and column numbers start at 0, an easy way to figure out the x, y
 Use [plot](/reference/led/plot) and [unplot](/reference/led/unplot) to turn a LED on or off
 
 ```blocks
-led.plot(0,0)
+led.plot(0,0);
+basic.pause(1000);
 led.unplot(0,0)
 ```
 

docs/device/serial.md

@@ -11,16 +11,35 @@ input.onButtonPressed(Button.A, () => {
 })
 ```
 
+Data is also automatically streamed to serial by the ** bar graph** block
+and picked up by the editor. This data can be streamed to the cloud as well.
+
+```blocks
+basic.forever(() => {
+   led.plotBarGraph(input.acceleration(Dimension.X), 0);
+});
+```
+
 ## How to read the micro:bit's serial output from your computer
 
 Unfortunately, using the serial library requires quite a bit of a setup.
 
+### BBC micro:bit Chrome Extension
+
+If you are using the Google Chrome browser, you can use our extension to get serial data streaming in the editor.
+
+* Install the [Extension for BBC micro:bit](https://chrome.google.com/webstore/detail/extension-for-bbc-microbi/cihhkhnngbjlhahcfmhekmbnnjcjdbge?hl=en-US) on the Chrome Web Store.
+* Restart Chrome and open the web editor.
+
 ### Windows
 
 You must install a device driver (for the computer to recognize the serial interface of the micro:bit); then, you must also install a terminal emulator (which is going to connect to the micro:bit and read its output). Here's how to do it:
 
 * Follow instructions at https://developer.mbed.org/handbook/Windows-serial-configuration in order to install the device driver
-* Install a terminal emulator; we recommend [Tera Term](https://ttssh2.osdn.jp/index.html.en). At the time of this writing, the latest version is 4.88 and can be downloaded [from here](http://en.osdn.jp/frs/redir.php?m=jaist&f=%2Fttssh2%2F63767%2Fteraterm-4.88.exe). Follow the instructions from the installer.
+
+#### Windows > Tera Term
+
+* Install the terminal emulator [Tera Term](https://ttssh2.osdn.jp/index.html.en). At the time of this writing, the latest version is 4.88 and can be downloaded [from here](http://en.osdn.jp/frs/redir.php?m=jaist&f=%2Fttssh2%2F63767%2Fteraterm-4.88.exe). Follow the instructions from the installer.
 
 Once both the driver and the terminal emulator are installed, plug in the micro:bit and wait until the device is fully setup. Then, open TeraTerm.
 
@@ -32,7 +51,7 @@ You should be good. Feel free to hit `Setup` > `Save Setup` in the menus to eras
 
 Please note that Windows will assign you a different COM port if you plug in another micro:bit. If you're juggling between micro:bits, you'll have to change the COM port every time.
 
-### Alternative Windows setup with Putty
+#### Windows > Putty
 
 If you prefer another terminal emulator (such as [PuTTY](http://www.putty.org/)), here are some instructions.
 

docs/docs.md

@@ -27,7 +27,7 @@ input.onButtonPressed(Button.B, () => {
 * **[getting started](/getting-started)**   
 * Browse the [API reference](/reference)
 * Learn more about the [device](/device)
-* Get started with [lessons](/lessons)
+* Get started with [projects](/projects)
 * Frequently Asked Question [faq](/faq)
 * Follow up with the [release notes](/release-notes)
 

docs/lessons.md

@@ -51,7 +51,6 @@
 ### ~column 
 
 ## Maker
-* [The Watch](/lessons/the-watch), design and create The Watch
 * [Hack your Headphones](/lessons/hack-your-headphones), create music on the BBC micro:bit by hacking your headphones
 * [Banana Keyboard](/lessons/banana-keyboard), create music with fruits
 * [Telegraph](/lessons/telegraph), play the telegraph game between two BBC micro:bits

docs/lessons/stem.md

@@ -38,7 +38,6 @@ Overview of Blocks lessons for the BBC micro:bit.
 
 ## Engineering
 
-* [The Watch](/lessons/the-watch), design and create The Watch
 * [Truth or dare](/lessons/truth-or-dare), a game that forces each player to reveal a secret or do something funny with if statement
 * [Spinner](/lessons/spinner), spin the arrow with multiple if statements
 * [Dice roll](/lessons/dice-roll), spin with more if statements

docs/lessons/the-watch.md

@@ -1,23 +0,0 @@
-# the watch lesson
-
-display beautiful images on the BBC micro:bit.
-
-![](/static/mb/lessons/the-watch-0.png)
-
-## Topic
-
-The Watch
-
-## Quick Links
-
-* [activity](/lessons/the-watch/activity)
-
-
-
-## Prior learning/place of lesson in scheme of work
-
-Learn how to design the BBC micro:bit watch with household supplies.
-
-## Objectives
-
-* learn how to design and make the watch with the BBC micro:bit

docs/open-source.md

@@ -4,6 +4,6 @@ The editor is open source on GitHub under the MIT license. Contributions are wel
 
 ### Repos
 
+* [microsoft/pxt-microbit](https://github.com/Microsoft/pxt-microbit), PXT target for BBC micro:bit, also includes the documentation.
 * [microbit/pxt](https://github.com/Microsoft/pxt), programming experience toolkit (PXT)
-* [microsoft/pxt-microbit](https://github.com/Microsoft/pxt-microbit), PXT target for BBC micro:bit
 * [microsoft/pxt-microbit-core](https://github.com/Microsoft/pxt-microbit-core), Yotta module used to build the BBC micro:bit runtime

docs/projects.md

@@ -1,15 +1,46 @@
 # Projects
 
+![](/static/mb/projects/all10.png)
 
-### @short Projects
+## [Flashing Heart](/projects/flashing-heart)
 
-### ~column 
+![](/static/mb/projects/a1-display.png)
 
-## Beginner
+## [Smiley Buttons](/projects/smiley-buttons)
 
-* [Rock Paper Scissors](/projects/rock-paper-scissors)
+![](/static/mb/projects/a2-buttons.png)
+
+## [Love Meter](/projects/love-meter)
+
+![](/static/mb/projects/a3-pins.png)
+
+## [Rock Paper Scissors](/projects/rock-paper-scissors)
+
+![](/static/mb/projects/a4-motion.png)
+
+## [Compass](/projects/compass)
+
+![](/static/mb/projects/a5-compass.png)
+
+## [Hack your headphones](/lessons/hack-your-headphones/activity)
+
+![](/static/mb/projects/a6-music.png)
+
+## [Banana keyboard](/lessons/banana-keyboard/activity)
+
+![](/static/mb/projects/a7-conductive.png)
+
+## [Telegraph](/lessons/telegraph/activity)
+
+![](/static/mb/projects/a8-network.png)
+
+## Radio
+
+![](/static/mb/projects/a9-radio.png)
+
+## [Watch](/projects/the-watch)
+
+![](/static/mb/projects/a10-watch.png)
 
-### ~
 
-### ~column 
 

docs/projects/a1-display.md

@@ -1,34 +0,0 @@
-## Getting started
-	• Go to https://m.pxt.io/
-	• To create a new project, click new Project
-Tap or click Blocks.
-
-## Step 1
-
-Use [show leds](/reference/basic/showLeds) and make your code look like this:
-
-```blocks
-basic.showLeds(`
-. # . # .
-# # # # #
-# # # # #
-. # # # .
-. . # . .`);
-```
-
-Once you are done coding, don't forget to run your code with the Play button.
-
-## Step 2
-
-Add a [pause](/reference/basic/pause) to wait and [clear screen](/reference/basic/clearScreen) to turn off the LEDs.
-
-```blocks
-basic.showLeds(`
-. # . # .
-# # # # #
-# # # # #
-. # # # .
-. . # . .`);
-basic.pause(500);
-basic.clearScreen();
-```

docs/projects/compass.md

@@ -0,0 +1,112 @@
+# compass activity
+
+![](/static/mb/projects/a5-compass.png)
+
+Display the direction that the micro:bit is facing using the compass 
+
+### ~avatar avatar
+
+Welcome! This guided tutorial will show you how to program a script that displays the direction the micro:bit is pointing. Let's get started!
+
+### ~
+
+
+## Step 1
+
+Create a loop that will continuously update the reading of the compass.
+
+
+```blocks
+basic.forever(() => {
+    
+})
+```
+
+## Step 2
+
+Store the reading of the micro:bit in a variable called `degrees`.
+
+```blocks
+basic.forever(() => {
+    let degrees = input.compassHeading()
+})
+```
+
+## Step 3
+
+If `degrees` is less than `45`, then the compass heading is mostly pointing toward North. Display `N` on the micro:bit.
+
+```blocks
+basic.forever(() => {
+    let degrees = input.compassHeading();
+    if (degrees < 45) {
+        basic.showString("N");
+    }
+});
+```
+
+## Step 4
+
+If `degrees` is less than 135, the micro:bit is mostly pointing East. Display `E` on the micro:bit.
+
+
+```blocks
+basic.forever(() => {
+    let degrees = input.compassHeading();
+    if (degrees < 45) {
+        basic.showString("N");
+    }
+    else if (degrees < 135) {
+        basic.showString("E");
+    }
+});
+```
+
+## Step 5
+
+If `degrees` is less than 225, the micro:bit is mostly pointing South. Display `S` on the micro:bit.
+
+
+```blocks
+basic.forever(() => {
+    let degrees = input.compassHeading();
+    if (degrees < 45) {
+        basic.showString("N");
+    }
+    else if (degrees < 135) {
+        basic.showString("E");
+    }
+    else if (degrees < 225) {
+        basic.showString("S");
+    }
+});
+```
+
+## Step 6
+
+If none of these conditions returned true, then the micro:bit must be pointing West. Display `W` on the micro:bit.
+
+```blocks
+basic.forever(() => {
+    let degrees = input.compassHeading();
+    if (degrees < 45) {
+        basic.showString("N");
+    }
+    else if (degrees < 135) {
+        basic.showString("E");
+    }
+    else if (degrees < 225) {
+        basic.showString("S");
+    }
+    else {
+        basic.showString("W");
+    }
+});
+```
+
+### ~avatar avatar
+
+Excellent, you're ready to continue with the [challenges](/lessons/compass/challenges)!
+
+### ~
+

docs/projects/flashing-heart.md

@@ -0,0 +1,94 @@
+![](/static/mb/projects/a1-display.png)
+
+Use the LEDs to display a flashing heart.
+
+## Step 1
+
+Use [show leds](/reference/basic/showLeds) and make your code look like this:
+
+```blocks
+basic.showLeds(`
+. # . # .
+# # # # #
+# # # # #
+. # # # .
+. . # . .`);
+```
+
+## Step 2
+
+Add a [pause](/reference/basic/pause) to wait and [clear screen](/reference/basic/clearScreen) to turn off the LEDs.
+
+```blocks
+basic.showLeds(`
+. # . # .
+# # # # #
+# # # # #
+. # # # .
+. . # . .`);
+basic.pause(500);
+basic.clearScreen();
+```
+
+## Step 3
+
+Put a [forever loop](/reference/basic/forever) around it.
+
+```blocks
+basic.forever(() => {
+basic.showLeds(`
+. # . # .
+# # # # #
+# # # # #
+. # # # .
+. . # . .`);
+basic.pause(500);
+basic.clearScreen();
+})
+```
+
+## Step 4
+
+Add a [pause](/reference/basic/pause) to wait after clearing the screen.
+
+```blocks
+basic.forever(() => {
+basic.showLeds(`
+. # . # .
+# # # # #
+# # # # #
+. # # # .
+. . # . .`);
+basic.pause(500);
+basic.clearScreen();
+basic.pause(500);
+})
+```
+
+## Step 5
+
+Add a second image of a broken heart. 
+
+
+```blocks
+basic.forever(() => {
+basic.showLeds(`
+. # . # .
+# # # # #
+# # # # #
+. # # # .
+. . # . .`);
+basic.pause(500);
+basic.clearScreen();
+basic.pause(500);
+basic.showLeds(`
+. # . # .
+# . # # #
+# . . . #
+. # # # .
+. . # . .`);
+basic.pause(500);
+basic.clearScreen();
+basic.pause(500);
+})
+```

docs/projects/love-meter.md

@@ -0,0 +1,48 @@
+![](/static/mb/projects/a3-pins.png)
+
+Use pins P0, P1 and P2 to change the display by creating a circuit with your body.
+
+## Step 1
+
+Use [on pin pressed](/reference/input/on-pin-pressed) to show a random number
+when pin P0 is pressed (hold the GND pin with other hand):
+
+```blocks
+input.onPinPressed(TouchPin.P0, () => {
+    basic.showNumber(Math.random(11));
+});
+```
+## Step 2
+
+Show a string when pin P1 is pressed:
+
+```blocks
+input.onPinPressed(TouchPin.P0, () => {
+    basic.showNumber(Math.random(11));
+});
+input.onPinPressed(TouchPin.P1, () => {
+    basic.showString("LOVE?");
+});
+```
+
+## Step 3
+
+Show a heart when pin P2 is pressed:
+
+```blocks
+input.onPinPressed(TouchPin.P0, () => {
+    basic.showNumber(Math.random(11));
+});
+input.onPinPressed(TouchPin.P1, () => {
+    basic.showString("LOVE?");
+});
+input.onPinPressed(TouchPin.P2, () => {
+    basic.showLeds(`
+        . # # # .
+        # # # # #
+        # # # # #
+        . # # # .
+        . . # . .
+        `);
+});
+```

docs/projects/rock-paper-scissors.md

@@ -1,5 +1,7 @@
 # rock paper scissors
 
+![](/static/mb/projects/a4-motion.png)
+
 ### ~avatar avatar
 
 ```sim

docs/projects/smiley-buttons.md

@@ -0,0 +1,67 @@
+![](/static/mb/projects/a2-buttons.png)
+
+Use buttons to show a smiley or frowny face. 
+
+## Step 1
+
+Use [show leds](/reference/basic/showLeds) to make a smiley face:
+
+```blocks
+basic.showLeds(`
+. # . # .
+. # . # .
+. . . . .
+# . . . #
+. # # # .`);
+```
+
+## Step 2
+
+Add an input block for when [button A is pressed](/reference/input/button-is-pressed), and put a
+frowny face inside it:
+
+```blocks
+basic.showLeds(`
+. # . # .
+. # . # .
+. . . . .
+# . . . #
+. # # # .`);
+input.onButtonPressed(Button.A, () => { 
+    basic.showLeds(`
+    . # . # .
+    . # . # .
+    . . . . .
+    . # # # .
+    # . . . #`);
+});
+```
+
+## Step 3
+
+Now add blocks so that when [button B is pressed](/reference/input/button-is-pressed), a smiley appears:
+
+```blocks
+basic.showLeds(`
+. # . # .
+. # . # .
+. . . . .
+# . . . #
+. # # # .`);
+input.onButtonPressed(Button.A, () => { 
+    basic.showLeds(`
+    . # . # .
+    . # . # .
+    . . . . .
+    . # # # .
+    # . . . #`);
+});
+input.onButtonPressed(Button.B, () => { 
+    basic.showLeds(`
+    . # . # .
+    . # . # .
+    . . . . .
+    # . . . #
+    . # # # .`);
+});
+```

docs/projects/the-watch.md

@@ -1,6 +1,4 @@
-# The watch activity
-
-Control images with variables. 
+![](/static/mb/projects/a10-watch.png)
 
 # micro:bit watch
 
@@ -152,7 +150,7 @@ Your watch is ready!
 
 ### ~avatar avatar
 
-Excellent, you're ready to continue with the [challenges](/lessons/rock-paper-scissors/activity)!
+Excellent, you're ready to continue with the [challenges](/projects/rock-paper-scissors)!
 
 ### ~
 

docs/reference.md

@@ -1,10 +1,6 @@
 # Reference
 
 ```namespaces
-for (let i = 0;i<5;++i) {}
-if (true){}
-let x = 0;
-Math.random(5);
 basic.showNumber(0);
 input.onButtonPressed(Button.A, () => {
     
@@ -21,8 +17,15 @@ images.createImage(`
 . . . . .
 `);
 pins.digitalReadPin(DigitalPin.P0);
-serial.writeValue(x, 0);
+serial.writeNumber(0);
 control.inBackground(() => {
     
 });
+
 ```
+<!-- No language reference for now, until
+for (let i = 0;i<5;++i) {}
+if (true){}
+let x = 0;
+Math.random(5);
+-->

docs/reference/basic/clear-screen.md

@@ -21,10 +21,6 @@ basic.showLeds(`
 basic.clearScreen()
 ```
 
-### Lessons
-
-[blink](/lessons/blink), [flashing heart](/lessons/flashing-heart), [screen wipe](/lessons/screen-wipe)
-
 ### See also
 
 [set brightness](/reference/led/set-brightness), [unplot](/reference/led/unplot), [plot](/reference/led/plot), [Image](/reference/images/image), [clear](/reference/basic/clear-screen)

docs/reference/basic/forever.md

@@ -63,10 +63,6 @@ input.onButtonPressed(Button.A, () => {
 })
 ```
 
-### Lessons
-
-[blink](/lessons/blink), [snowflake-fall](/lessons/snowflake-fall), [flashing-heart](/lessons/flashing-heart)
-
 ### See also
 
 [while](/reference/loops/while), [on button pressed](/reference/input/on-button-pressed), [in background](/reference/control/in-background)

docs/reference/basic/pause.md

@@ -24,10 +24,6 @@ for (let i = 0; i < 5; i++) {
 }
 ```
 
-### Lessons
-
-[blink](/lessons/blink), [lucky 7](/lessons/lucky-7), [smiley](/lessons/smiley), [flashing heart](/lessons/flashing-heart)
-
 ### See also
 
 [while](/reference/loops/while), [running time](/reference/input/running-time), [for](/reference/loops/for)

docs/reference/basic/show-animation.md

@@ -62,8 +62,3 @@ basic.showAnimation(`
 Use [forever](/reference/basic/forever) to show an animation over and over.
 
 ### ~
-
-### Lessons
-
-[smiley](/lessons/smiley), [snowflake fall](/lessons/snowflake-fall), [rotation animation](/lessons/rotation-animation)
-

docs/reference/basic/show-leds.md

@@ -1,6 +1,6 @@
 # Show LEDs
 
-Display an image on the BBC micro:bit's [LED screen](/device/screen).
+Shows a picture on the [LED screen](/device/screen).
 
 ```sig
 basic.showLeds(`
@@ -15,13 +15,13 @@ basic.showLeds(`
 
 ### Parameters
 
-* `leds` is a [String](/reference/types/string) that shows which LEDs are on and off.
-* `ms` is an optional [Number](/reference/types/number) that shows how many milliseconds to wait after showing a picture.
-If you are programming with blocks, `ms` starts out as 400 milliseconds.
+* `leds` is a [string](/reference/types/string) that means which LEDs are on and off.
+* `interval` is an optional [number](/reference/types/number) that means how many milliseconds to wait after showing a picture.
+If you are programming with blocks, `interval` starts out as 400 milliseconds.
 
 ### Example
 
-Open the `basic` card in the Block Editor and select the `show leds` blocks.
+This program shows a picture with the ``show leds`` function.
 
 ```blocks
 basic.showLeds(`
@@ -34,11 +34,12 @@ basic.showLeds(`
 )
 ```
 
-If you are programming in JavaScript, `#` means an LED that is turned on and `.` means an LED that is turned off.
+### ~hint
 
-### Lessons
+If you are programming in JavaScript, `#` means an LED that is turned
+on and `.` means an LED that is turned off.
 
-[smiley](/lessons/smiley), [flashing heart](/lessons/flashing-heart), [magic logo](/lessons/magic-logo)
+### ~
 
 ### See also
 

docs/reference/basic/show-number.md

@@ -42,10 +42,6 @@ for (let i = 0; i < 6; i++) {
 * Use [show string](/reference/basic/show-string) to show a [String](/reference/types/string) with letters on the screen.
 * Use [show animation](/reference/basic/show-animation) to show a group of pictures on the screen, one after another.
 
-### Lessons
-
-* [lucky 7](/lessons/lucky-7)
-
 ### See also
 
 [show string](/reference/basic/show-string), [show animation](/reference/basic/show-animation), [Number](/reference/types/number), [math library](/reference/math)

docs/reference/basic/show-string.md

@@ -31,10 +31,6 @@ basic.showString(s)
 * Use [show number](/reference/basic/show-number) to show a number on the [LED screen](/device/screen).
 * Use [show animation](/reference/basic/show-animation) to show a group of pictures on the screen, one after another.
 
-### Lessons
-
-[answering machine](/lessons/answering-machine), [rock paper scissors](/lessons/rock-paper-scissors), [love meter](/lessons/love-meter)
-
 ### See also
 
 [String](/reference/types/string), [show number](/reference/basic/show-number), [show animation](/reference/basic/show-animation)

docs/reference/game/change-score-by.md

@@ -24,8 +24,3 @@ export function addScore(points: number)
 ```
 export function score() : number
 ```
-
-### Lessons
-
-[game of chance](/lessons/game-of-chance), [game counter](/lessons/game-counter)
-

docs/reference/game/change.md

@@ -19,8 +19,3 @@ Sprite will change the y position by this number
 ```
 export function changeYBy(_this: micro_bitSprites.LedSprite, y: number)
 ```
-
-### Lessons
-
-[game of chance](/lessons/game-of-chance) | [game counter](/lessons/game-counter)
-

docs/reference/game/game-library.md

@@ -146,8 +146,3 @@ You can also end the game by calling the `game -> game over` function:
 ```
 game.gameOver()
 ```
-
-### Lessons
-
-[game of chance](/lessons/game-of-chance) | [game counter](/lessons/game-counter)
-

docs/reference/game/game-over.md

@@ -18,7 +18,3 @@ You can end the game by calling the `game -> game over` function:
 game.gameOver()
 ```
 
-### Lessons
-
-[game of chance](/lessons/game-of-chance)
-

docs/reference/game/move.md

@@ -5,8 +5,3 @@ Sprite move by a certain number of LEDs
 ```
 export function move(_this: micro_bitSprites.LedSprite, leds: number)
 ```
-
-### Lessons
-
-[game of chance](/lessons/game-of-chance) | [game counter](/lessons/game-counter)
-

docs/reference/game/position.md

@@ -11,8 +11,3 @@ Reports the y position of a sprite on the LED screen
 ```
 export function y(_this: micro_bitSprites.LedSprite) : number
 ```
-
-### Lessons
-
-[game of chance](/lessons/game-of-chance) | [game counter](/lessons/game-counter)
-

docs/reference/game/reports.md

@@ -25,8 +25,3 @@ Reports the current direction of a sprite on the LED screen
 ```
 export function direction(_this: micro_bitSprites.LedSprite) : number
 ```
-
-### Lessons
-
-[game of chance](/lessons/game-of-chance) | [game counter](/lessons/game-counter)
-

docs/reference/game/score.md

@@ -43,7 +43,3 @@ If your game has a time limit, you can start a countdown in which case `game->cu
 export function startCountdown(ms: number)
 ```
 
-### Lessons
-
-[game of chance](/lessons/game-of-chance), [game counter](/lessons/game-counter)
-

docs/reference/game/start-countdown.md

@@ -40,8 +40,3 @@ If your game has a time limit, you can start a countdown in which case `game->cu
 ```
 export function startCountdown(ms: number)
 ```
-
-### Lessons
-
-[bop it](/lessons/bop-it) | [game of chance](/lessons/game-of-chance) | [game counter](/lessons/game-counter)
-

docs/reference/game/touching.md

@@ -6,7 +6,3 @@ Reports true if sprite is touching specified sprite
 export function isTouching(_this: micro_bitSprites.LedSprite, other: micro_bitSprites.LedSprite) : boolean
 ```
 
-### Lessons
-
-[game of chance](/lessons/game-of-chance) | [game counter](/lessons/game-counter)
-

docs/reference/game/turn.md

@@ -12,7 +12,3 @@ Rotates a sprite to the left by a certain number of degrees
 export function turnLeft(_this: micro_bitSprites.LedSprite, degrees: number)
 ```
 
-### Lessons
-
-[game of chance](/lessons/game-of-chance) | [game counter](/lessons/game-counter)
-

docs/reference/images/create-image.md

@@ -29,10 +29,6 @@ input.onGesture(Gesture.Shake, () => {
 })
 ```
 
-### Lessons
-
-[rock paper scissors](/lessons/rock-paper-scissors), [digital pet](/lessons/digital-pet), [offset-image](/lessons/offset-image)
-
 ### See also
 
 [show animation](/reference/basic/show-animation), [image](/reference/images/image), [show image](/reference/image/show-image), [scroll image](/reference/image/scroll-image)

docs/reference/images/image.md

@@ -46,10 +46,6 @@ You should see code similar to this:
 * [show image](/reference/images/show-image): show an image on the screen
 * [scroll image](/reference/images/scroll-image): scroll an image on the screen
 
-### Lessons
-
-* [smiley](/lessons/smiley)
-
 ### See also
 
 [Show LEDs](/reference/basic/show-leds), [create image](/reference/images/create-image), [show image](/reference/images/show-image), [LED screen](/device/screen)

docs/reference/images/plot-frame.md

@@ -31,10 +31,6 @@ let img = images.createImage(`
 img.plotFrame(1)
 ```
 
-### Lessons
-
-[smiley](/lessons/smiley), [flashing heart](/lessons/flashing-heart), [magic logo](/lessons/magic-logo)
-
 ### See also
 
 [create image](/reference/images/create-image), [show animation](/reference/basic/show-animation), [image](/reference/images/image), [show image](/reference/images/show-image), [scroll image](/reference/images/scroll-image)

docs/reference/images/plot-image.md

@@ -31,10 +31,6 @@ let img = images.createImage(`
 img.plotImage(0)
 ```
 
-### Lessons
-
-[smiley](/lessons/smiley), [flashing heart](/lessons/flashing-heart), [magic logo](/lessons/magic-logo)
-
 ### See also
 
 [create image](/reference/images/create-image), [show animation](/reference/basic/show-animation), [image](/reference/images/image), [show image](/reference/images/show-image), [scroll image](/reference/images/scroll-image)

docs/reference/images/show-frame.md

@@ -31,10 +31,6 @@ let img = images.createImage(`
 img.showFrame(1)
 ```
 
-### Lessons
-
-[smiley](/lessons/smiley), [flashing heart](/lessons/flashing-heart), [magic logo](/lessons/magic-logo)
-
 ### See also
 
 [create image](/reference/images/create-image), [show animation](/reference/basic/show-animation), [image](/reference/images/image), [show image](/reference/images/show-image), [scroll image](/reference/images/scroll-image)

docs/reference/images/show-image.md

@@ -45,10 +45,6 @@ for (let i = 0; i < 5; i++) {
 }
 ```
 
-### Lessons
-
-[rock paper scissors](/lessons/rock-paper-scissors), [digital pet](/lessons/digital-pet), [offset-image](/lessons/offset-image)
-
 ### See also
 
 [show animation](/reference/basic/show-animation), [image](/reference/images/image), [create image](/reference/images/create-image), [scroll image](/reference/images/scroll-image)

docs/reference/input/acceleration.md

@@ -2,46 +2,39 @@
 
 Get the acceleration value (milli g-force), in one of three specified dimensions.
 
+Find the acceleration of the micro:bit (how fast it is speeding up or slowing down).
+
 ```sig
 input.acceleration(Dimension.X);
 ```
 
+## ~hint
+
+You measure acceleration with the **milli-g**, which is 1/1000 of a **g**.
+A **g** is as much acceleration as you get from Earth's gravity.
+
+## ~
+
+
+
 ### Parameters
 
-* dimension : [String](/reference/types/string) - one of three values specifying the axis of acceleration: ``x`` (left/right); ``y`` (forward/backwards); ``z`` (up/down)
+* which direction you are checking for acceleration, either `Dimension.X` (left and right), `Dimension.Y` (forward and backward), or `Dimension.Z` (up and down)
 
 ### Returns
 
-* [Number](/reference/types/number) - acceleration, in milli-gravities. When the micro:bit is laying flat with the screen up, x=0, y=0 and z=-1023.
+* a [number](/reference/types/number) that means the amount of acceleration. When the micro:bit is lying flat on a surface with the screen pointing up, `x` is `0`, `y` is `0`, and `z` is `-1023`.
 
 ### Example: bar chart
 
-Use the ``plot bar chart`` to visual the acceleration on the LED screen.
+This example shows the acceleration of the micro:bit with a bar graph.
 
 ```blocks
 basic.forever(() => {
-    led.plotBarGraph(input.acceleration("x"), 1023)
+    led.plotBarGraph(input.acceleration(Dimension.X), 1023)
 })
 ```
 
-### Example: micro:bit leveller
-
-The following example uses the `acceleration` and the `plot` function to help you move the micro:bit until it's level (the centre LED is *on* when the device is level). When running this code in a web browser, move your mouse to simulate the accelerometer.
-
-```blocks
-basic.forever(() => {
-    let ax = input.acceleration(Dimension.X)
-    let x = pins.map(-1023, 1023, 0, 4, ax)
-    let ay = input.acceleration("y")
-    let y = pins.map(-1023, 1023, 0, 4, ay)
-    basic.clearScreen()
-    led.plot(x, y)
-})
-```
-
-### Lessons
-
-[zoomer](/lessons/zoomer)
 
 ### See also
 

docs/reference/input/button-is-pressed.md

@@ -33,10 +33,6 @@ basic.forever(() => {
 })
 ```
 
-### Lessons
-
-[zoomer](/lessons/zoomer)
-
 ### See also
 
 [on button pressed](/reference/input/on-button-pressed), [if](/reference/logic/if), [forever](/reference/basic/forever)

docs/reference/input/compass-heading.md

@@ -1,6 +1,10 @@
 # Compass Heading
 
-Get the compass heading of the micro:bit in degrees. Your micro:bit has a built-in **magnetometer** so it can your direction with respect to the North Magnetic Pole.
+Find which direction on a compass the micro:bit is facing.
+
+The micro:bit measures the **compass heading** from `0` to `360`
+degrees with its **magnetometer** chip. Different numbers mean north,
+east, south, and west.
 
 ```sig
 input.compassHeading();
@@ -8,15 +12,12 @@ input.compassHeading();
 
 ### Returns
 
-* [Number](/reference/types/number) - the heading in degrees (0 to 360 degrees). If the compass is calibrating, it returns ``-1003``.
-
-## Simulator
-
-Calibration does not work on the simulator.
+* a [number](/reference/types/number) from `0` to `360` degrees, which means the compass heading. If the compass isn't ready, it returns `-1003`.
 
 ### Example
 
-The following code gets the compass heading and stores it in the `degrees` variable:
+This program finds the compass heading and stores it in the
+`degrees` variable.
 
 ```blocks
 let degrees = input.compassHeading()
@@ -24,13 +25,16 @@ let degrees = input.compassHeading()
 
 ### ~hint 
 
-When running code with this function in a web browser, click and drag the on-screen compass needle to change heading.
+When you run a program that uses this function in a browser, click and drag
+the compass needle on the screen to change the compass heading.
 
 ### ~
 
 ### Example: compass
 
-The following example gets the `compass heading` and then displays a letter depending on the value of `degrees`: N for north, E for East, S for South, and W for West.
+This program finds the compass heading and then shows a letter
+that means whether the micro:bit is facing north (N), south (S),
+east (E), or west (W).
 
 ```blocks
 basic.forever(() => {
@@ -47,17 +51,14 @@ basic.forever(() => {
 
 ### Calibration
 
-On the first use of the compass, the **calibration** procedure will automatically start. The user must draw a circle with the device until it is fully calibrated.
+Every time you start to use the compass (for example, if you have just
+turned the micro:bit on), the micro:bit will start to **calibrate**
+(adjust itself).  It will ask you to draw a circle by tilting the
+micro:bit.
 
-An enclosure made from metal, or using in proximity of metal objects, might affect the accuracy of the reading and calibration.
-
-During calibration, ``compass heading`` returns ``-1003``.
-
-### Lessons
-
-[compass](/lessons/compass)
+If you are calibrating or using the compass near metal, it might
+confuse the micro:bit.
 
 ### See also
 
 [acceleration](/reference/input/acceleration)
-

docs/reference/input/light-level.md

@@ -43,8 +43,6 @@ basic.forever(() => {
 })
 ```
 
-### Lessons
-
 ### See also
 
 [acceleration](/reference/input/acceleration), [compass-heading](/reference/input/compass-heading)

docs/reference/input/magnetic-force.md

@@ -1,27 +1,35 @@
 # Magnetic Force
 
-Get the magnetic force (micro Teslas), in one of three specified dimensions.
+Find the amount of magnetic force (the strength of a magnet) in the direction you say.
 
 ```sig
 input.magneticForce(Dimension.X);
 ```
 
+## ~hint
+
+The micro:bit measures magnetic force with **microteslas**.
+
+## ~
+
+
 ### Parameters
 
-* dimension : [String](/reference/types/string) - one of three values specifying the axis of the force: ``x`` (left/right); ``y`` (forward/backwards); ``z`` (up/down); ``strength`` (the length of the vector)
+* a [string](/reference/types/string) that says which direction the micro:bit should measure magnetic force in: either `x` (the left-right direction), `y` (the forward/backward direction), or `z` (the up/down direction)
 
 ### Returns
 
-* [Number](/reference/types/number) - magnetic force, in micro-Teslas.
+* a [number](/reference/types/number) of microteslas that means the strength of the magnet
 
 ### Example: metal detector
 
-The following example uses the `magnetic force` to control the brightness of the screen. When the magnetic force increases, the center LED will appear brighter.
+This program makes the center LED of the micro:bit get brighter when
+the magnetic force is stronger, and dimmer when it is weaker.
 
 ```blocks
 led.plot(2, 2)
 basic.forever(() => {
-    let f = input.magneticForce(Dimension.X)
+    let f = input.magneticForce("x")
     led.setBrightness(f / 2000)
 })
 ```
@@ -29,4 +37,3 @@ basic.forever(() => {
 ### See also
 
 [compass heading](/reference/input/compass-heading)
-

docs/reference/input/on-button-pressed.md

@@ -41,10 +41,6 @@ Otherwise, sometimes they would show a `0`.
 
 ### ~
 
-### Lessons
-
-[smiley](/lessons/smiley), [answering machine](/lessons/answering-machine), [screen wipe](/lessons/screen-wipe), [rotation animation](/lessons/rotation-animation)
-
 ### See also
 
 [button is pressed](/reference/input/button-is-pressed), [forever](/reference/basic/forever), [random](/reference/math/math)

docs/reference/input/on-gesture.md

@@ -1,19 +1,17 @@
 # On Gesture
 
-Register an [event handler](/reference/event-handler) that will execute whenever the user executes a gesture withthe BBC micro:bit.
+Start an [event handler](/reference/event-handler) (part of the
+program that will run when something happens) This handler works when
+you do a **gesture** (like shake, tilt, or drop the micro:bit).
 
 ```sig
 input.onGesture(Gesture.Shake,() => {
 })
 ```
 
-## Gestures
+## Example: random number
 
-
-
-### Example: random number
-
-The following example displays a number from 0-9 on the screen when you shake the BBC micro:bit.
+This program shows a number from `0` to `9` when you shake the micro:bit.
 
 ```blocks
 input.onGesture(Gesture.Shake,() => {
@@ -22,24 +20,3 @@ input.onGesture(Gesture.Shake,() => {
 })
 ```
 
-### Example: rock, paper, scissors
-
-The following example shows one of three images (rock, paper, or scissors) when you shake the BBC micro:bit.
-
-```blocks
-input.onGesture(Gesture.Shake,() => {
-    let img = images.createImage(`
-. . . . . # # # # # . . . . #
-. # # # . # . . . # # # . # .
-. # # # . # . . . # . # # . .
-. # # # . # . . . # # # . # .
-. . . . . # # # # # . . . . #
-`)
-    img.showFrame(Math.random(3))
-})
-```
-
-### Lessons
-
-[bounce image](/lessons/bounce-image), [rock paper scissors](/lessons/rock-paper-scissors)
-

docs/reference/input/on-pin-pressed.md

@@ -1,17 +1,31 @@
 # On Pin Pressed
 
-Register an [event handler](/reference/event-handler) that will execute whenever the user holds the `GND` pin with one hand, and presses pin `0`, `1`, or `2` with the other hand, thus completing a circuit; when you run a script with this function in a web browser, click pins 0 , 1, or 2 on the simulator.
+Start an [event handler](/reference/event-handler) (part of the program 
+that will run when something happens, like when a button is pressed). 
+This handler works when you press pin `0`, `1`, or `2` together with `GND`.
+When you are using this function in a web browser, click the pins on the screen instead of the ones
+on the BBC micro:bit.
 
-*Note* that this function works best when the BBC micro:bit is powered by AAA battery.
+If you hold the `GND` pin with one hand and touch pin `0`, `1`, or `2` with the other,
+a very small (safe) amount of electricity will flow through your body and back into
+the micro:bit. This is called **completing a circuit**. It's like you're a big wire!
 
 ```sig
 input.onPinPressed(TouchPin.P0, () => {
 })
 ```
 
+## ~hint
+
+This function works best when the BBC micro:bit is using batteries for power,
+instead of the USB cable.
+
+## ~
+
 ### Example: pin pressed counter
 
-This example counts how many times the P0 pin is pressed. Each time the pin is pressed, the global count variable is increased by 1 and displayed on the screen.
+This program counts how many times you press the `P0` pin. 
+Every time you press the pin, the program shows the number of times on the screen.
 
 ```blocks
 let count = 0
@@ -22,10 +36,6 @@ input.onPinPressed(TouchPin.P0, () => {
 })
 ```
 
-### Lessons
-
-[love meter](/lessons/love-meter)
-
 ### See also
 
 [BBC micro:bit pins](/device/pins), [pin is pressed](/reference/input/pin-is-pressed), [analog read pin](/reference/pins/analog-read-pin), [analog write pin](/reference/pins/analog-write-pin), [digital read pin](/reference/pins/digital-read-pin), [digital write pin](/reference/pins/digital-write-pin)

docs/reference/input/pin-is-pressed.md

@@ -1,24 +1,33 @@
 # Pin Is Pressed
 
-Gets the pin state (pressed or not pressed), by detecting when the user holds the `GND` pin with one hand, and presses pin `0`, `1`, or `2` with the other hand, thus completing a circuit.
+Find whether the pin you say is pressed or not pressed.
 
-*Note* that this function works best when the BBC micro:bit is powered by AAA battery.
+If you hold the `GND` pin with one hand and touch pin `0`, `1`, or `2` with the other,
+a very small (safe) amount of electricity will flow through your body and back into
+the micro:bit. This is called **completing a circuit**. It's like you're a big wire!
 
 ```sig
 input.pinIsPressed(TouchPin.P0);
 ```
 
+## ~hint
+
+This function works best when the BBC micro:bit is using batteries for power,
+instead of the USB cable.
+
+## ~
+
 ### Parameters
 
-* name - [String](/reference/types/string); the pin name ("P0", "P1", or "P2")
+* a [string](/reference/types/string) that holds the pin name (**P0**, **P1**, or **P2**)
 
 ### returns
 
-* [Boolean](/reference/types/boolean) - `true` if pressed, `false` if not pressed
+* a [boolean](/reference/types/boolean) that means whether the pin you say is pressed (`true` or `false`)
 
 ### Example
 
-This example displays 1 if P0 is pressed, and 0 if P0 is not pressed:
+This program shows `1` if `P0` is pressed, and `0` if `P0` is not pressed:
 
 ```blocks
 basic.forever(() => {

docs/reference/input/rotation.md

@@ -1,45 +1,58 @@
 # Rotation
 
-Get a rotation angle in degrees inferred from the accelerometer readings.
+Find how much the micro:bit is tilted in different directions.
 
 ```sig
 input.rotation(Rotation.Roll);
 ```
 
+## ~hint
+
+The BBC micro:bit has a part called the **accelerometer** that can
+check how the micro:bit is moving.
+
+## ~
+
 ### Parameters
 
-* kind: [String](/reference/types/string) - one of values specifying the kind of rotation: ``pitch`` (up/down around the ``x`` axis); ``roll`` (left/right around the ``y`` axis)
+* which direction you are checking: `Rotation.Pitch` (up and down) or `Rotation.Roll` (left and right)
 
 ### Returns
 
-* [Number](/reference/types/number) - angle, in degrees.
+* a [number](/reference/types/number) that means how much the microbit is tilted in the direction you say, from `0` to `360` degrees
 
-### Example: micro:bit leveller
+### Example: micro:bit leveler
 
-The following example uses the `rotation` and the `plot leds` function to help you move the BBC micro:bit until it's level: when it is level, a smiley shows up on the screen. When running this code in a web browser, move your mouse to simulate the rotation.
+This program helps you move the BBC micro:bit until it is level.  When
+it is level, the micro:bit shows a smiley.
 
-```sig
+If you are running this program in a browser, you can tilt the
+micro:bit with your mouse.
+
+
+```blocks
+let pitch = 0;
 basic.forever(() => {
-    let pitch = input.rotation(Rotation.Pitch)
-    let roll = input.rotation(Rotation.Roll)
+    pitch = input.rotation(Rotation.Pitch);
+    let roll = input.rotation(Rotation.Roll);
     if (Math.abs(pitch) < 10 && Math.abs(roll) < 10) {
-        basic.plotLeds(`
-. . . . .
-. # . # .
-. . . . .
-# . . . #
-. # # # .
-`)
+        basic.showLeds(`
+            . # . # .
+            . . . . .
+            . . . . .
+            # . . . #
+            . # # # .
+            `);
     } else {
-        basic.plotLeds(`
-# . . . #
-. # . # .
-. . # . .
-. # . # .
-# . . . #
-`)
+        basic.showLeds(`
+            # . . . #
+            . # . # .
+            . . # . .
+            . # . # .
+            # . . . #
+            `);
         }
-})
+	});
 ```
 
 ### See also

docs/reference/input/running-time.md

@@ -24,9 +24,6 @@ input.onButtonPressed(Button.B, () => {
 })
 ```
 
-### Lessons
-
-[speed button](/lessons/speed-button)
 
 ### See also
 

docs/reference/input/temperature.md

@@ -52,8 +52,6 @@ better thermometer.
 
 ### ~
 
-### Lessons
-
 ### See also
 
 [compass-heading](/reference/input/compass-heading), [acceleration](/reference/input/acceleration)

docs/reference/led/fade-in.md

@@ -24,10 +24,6 @@ for (let i = 0; i < 5; i++) {
 }
 ```
 
-### Lessons
-
-[glowing sword](/lessons/glowing-sword)
-
 ### See also
 
 [brightness](/reference/led/brightness), [fade out](/reference/led/fade-out), [set brightness](/reference/led/set-brightness)

docs/reference/led/fade-out.md

@@ -20,10 +20,6 @@ basic.showString("A", 1000)
 led.fadeOut(1000)
 ```
 
-### Lessons
-
-[glowing sword](/lessons/glowing-sword)
-
 ### See also
 
 [brightness](/reference/led/brightness), [fade in](/reference/led/fade-in), [set brightness](/reference/led/set-brightness)

docs/reference/led/plot-all.md

@@ -6,10 +6,6 @@ Turn on all the 25 LEDs on the [LED screen](/device/screen).
 led.plotAll()
 ```
 
-### Lessons
-
-[night light](/lessons/night-light)
-
 ### See also
 
 [LED screen](/device/screen), [clear screen](/reference/basic/clear-screen)

docs/reference/led/plot-leds.md

@@ -28,10 +28,6 @@ basic.plotLeds(`
 `)
 ```
 
-### Lessons
-
-[smiley](/lessons/smiley), [flashing heart](/lessons/flashing-heart), [magic logo](/lessons/magic-logo)
-
 ### See also
 
 [show animation](/reference/basic/show-animation), [image](/reference/images/image), [show image](/reference/images/show-image), [scroll image](/reference/images/scroll-image)

docs/reference/led/plot.md

@@ -1,35 +1,47 @@
 # Plot
 
-Turn on a LED light on the [LED screen](/device/screen). Specify which LED using x, y coordinates. Use [unplot](/reference/led/unplot) to turn a LED off.
+Turn on the LED light you say on the [LED screen](/device/screen).
 
 ```sig
 led.plot(0,0);
 ```
 
+## ~hint
+
+Use [unplot](/reference/led/unplot) to turn **off** an LED.
+
+## ~
+
 ### Parameters
 
-* x - [Number](/reference/types/number); the *x coordinate* or horizontal position (0, 1, 2, 3, 4)
-* y - [Number](/reference/types/number); the *y coordinate* or vertical position (0, 1, 2, 3, 4)
+* **x** is a [number](/reference/types/number) that means the horizontal spot on the LED screen (from left to right: 0, 1, 2, 3, or 4)
+* **y** is a [number](/reference/types/number) that means the vertical spot on the LED screen (from top to bottom: 0, 1, 2, 3, or 4)
 
-If a parameter is [out of bounds](/reference/out-of-bounds) (a value other than 0-4), then this function will do nothing.
+If a parameter is [out of bounds](/reference/out-of-bounds) (a value
+other than 0 to 4), then this function will do nothing.
 
-### x, y coordinates?
+### ~hint
 
-The LED screen is made up of 25 LEDs arranged in a 5x5 grid. To figure out the ``x``, ``y`` coordinates, see [LED screen](/device/screen).
+The LED screen is a solid square of LEDs with five LEDs on each side.
+To learn more about how you number the LEDs with ``x`` and ``y``
+coordinates, see [LED screen](/device/screen).
 
-This code turns on the centre LED:
+### ~
+
+### Example: One LED
+
+This program turns on the bottom right LED.
 
 ```blocks
-led.plot(2, 2)
+led.plot(4, 4)
 ```
 
-### Get the LED on/off state
 
-Use the [point](/reference/led/point) function to find out if a LED is on or off.
+### Example: Square
 
-### Example: a square
-
-The following example uses a [for loop](/reference/loops/for) and the `plot` function to turn on the LED lights along the edge of the screen, making a square:
+This program uses a [for loop](/reference/loops/for)
+and the `plot` function
+to make a square around the edges of the LED screen.
 
 ```blocks
 for (let i = 0; i < 5; i++) {
@@ -41,11 +53,13 @@ for (let i = 0; i < 5; i++) {
 }
 ```
 
-### Lessons
+### ~hint
 
-[blink](/lessons/blink), [beautiful  image](/lessons/beautiful-image), [strobe light](/lessons/strobe-light)
+Use the [point](/reference/led/point) function to find out if an LED is
+on or off.
+
+### ~
 
 ### See also
 
 [unplot](/reference/led/unplot), [point](/reference/led/point), [LED screen](/device/screen)
-

docs/reference/led/point.md

@@ -1,6 +1,7 @@
 # Point
 
-Get the on/off state of a LED on the [LED screen](/device/screen). Specify the LED using x, y coordinates.
+Find whether the LED you say on the 
+[LED screen](/device/screen) is on or off.
 
 ```sig
 led.point(0,0);
@@ -8,30 +9,36 @@ led.point(0,0);
 
 ### Parameters
 
-* x  - [Number](/reference/types/number); the *x coordinate* or horizontal position (0, 1, 2, 3, 4)
-* y - [Number](/reference/types/number); the *y coordinate* or vertical position (0, 1, 2, 3, 4)
+* **x** is a [number](/reference/types/number) that means the horizontal spot on the LED screen (from left to right: 0, 1, 2, 3, or 4)
+* **y** is a [number](/reference/types/number) that means the vertical spot on the LED screen (from top to bottom: 0, 1, 2, 3, or 4)
 
-If a parameter is [out of bounds](/reference/out-of-bounds) (a value other than 0-4), then this function will return `false`.
+If a parameter is [out of bounds](/reference/out-of-bounds) (a value
+other than 0 to 4), this function will return `false`.
 
 ### Returns
 
-* [Boolean](/reference/types/boolean) - `true` if the LED is *on* and `false` if the LED is *off*
+* a [boolean](/reference/types/boolean). If it is `true`, that means the LED is on. If it is `false`, that means the LED is off.
 
-### x, y coordinates?
+### ~hint
 
-The LED screen is made up of 25 LEDs arranged in a 5x5 grid. To figure out the ``x``, ``y`` coordinates, see [LED screen](/device/screen).
+The LED screen is a solid square of LEDs with five LEDs on each side.
+To learn more about how you number the LEDs with ``x`` and ``y``
+coordinates, see [LED screen](/device/screen).
 
-### Example: toggle off
+### ~
 
-If `point(1, 1)` returns `true`, then the following code turns off the LED:
+### Example: Toggle off
+
+This program turns the center LED (2, 2) off if it is already on.  (If
+it is already off, this program leaves it off.)
 
 ```blocks
-if (led.point(1, 1)) {
-    led.unplot(1, 1)
+if (led.point(2, 2)) {
+    led.unplot(2, 2)
 }
 ```
 
 ### See also
 
-[unplot](/reference/led/unplot), [plot](/reference/led/plot), [LED screen](/device/screen), [create image](/reference/images/create-image)
+[unplot](/reference/led/unplot), [plot](/reference/led/plot), [LED screen](/device/screen)
 

docs/reference/led/set-brightness.md

@@ -21,10 +21,6 @@ basic.pause(1000)
 led.setBrightness(127)
 ```
 
-### Lessons
-
-[night light](/lessons/night-light)
-
 ### See also
 
 [brightness](/reference/led/brightness), [fade in](/reference/led/fade-in), [fade out](/reference/led/fade-out), [LED screen](/device/screen)

docs/reference/led/unplot.md

@@ -1,35 +1,36 @@
 # Unplot
 
-Turn off a LED light on the [LED screen](/device/screen). Specify which LED using x, y coordinates. Use [plot](/reference/led/plot) to turn a LED on.
+Turn off the LED light you say on the [LED screen](/device/screen).
 
 ```sig
 led.unplot(0,0)
 ```
 
+## ~hint
+
+Use [plot](/reference/led/plot) to turn **on** an LED.
+
+## ~
+
 ### Parameters
 
-* x - [Number](/reference/types/number); the *x coordinate* or horizontal position (0, 1, 2, 3, 4)
-* y - [Number](/reference/types/number); the *y coordinate* or vertical position (0, 1, 2, 3, 4)
+* **x** is a [number](/reference/types/number) that means the horizontal spot on the LED screen (from left to right: 0, 1, 2, 3, or 4)
+* **y** is a [number](/reference/types/number) that means the vertical spot on the LED screen (from top to bottom: 0, 1, 2, 3, or 4)
 
-If a parameter is [out of bounds](/reference/out-of-bounds) (a value other than 0-4), this function will do nothing.
+If a parameter is [out of bounds](/reference/out-of-bounds) (a value
+other than 0 to 4), then this function will do nothing.
 
-### x, y coordinates?
+### ~hint
 
-The LED screen is made up of 25 LEDs arranged in a 5x5 grid. To figure out the ``x``, ``y`` coordinates, see [LED screen](/device/screen).
+The LED screen is a solid square of LEDs with five LEDs on each side.
+To learn more about how you number the LEDs with ``x`` and ``y``
+coordinates, see [LED screen](/device/screen).
 
-This code turns off centre LED:
+### ~
 
-```blocks
-led.unplot(2, 2)
-```
+### Example: Center off 
 
-### Get the LED on/off state
-
-Use the [point](/reference/led/point) function to find out if a LED is on or off.
-
-### Example: toggle off
-
-This code creates and shows an image on the micro:bit screen, and then clears the centre LED using `unplot`:
+This program shows a picture on the LED screen, and then turns off the center LED with `unplot`.
 
 ```blocks
 basic.showLeds(`
@@ -43,11 +44,14 @@ basic.pause(500)
 led.unplot(2, 2)
 ```
 
-### Lessons
+### ~hint
+
+Use the [point](/reference/led/point) function to find out if an LED is
+on or off.
+
+### ~
 
-[strobe light](/lessons/strobe-light)
 
 ### See also
 
-[plot](/reference/led/plot), [point](/reference/led/point), [LED screen](/device/screen), [create image](/reference/images/create-image)
-
+[plot](/reference/led/plot), [point](/reference/led/point), [LED screen](/device/screen)

docs/reference/logic/if.md

@@ -22,10 +22,6 @@ if(input.lightLevel()<100){
 
 If the [light level](/input/light-level) is `< 100`, this code sets the brightness to `255`:
 
-### Lessons
-
-[love meter](/lessons/love-meter), [zoomer](/lessons/zoomer)
-
 ### See also
 
 [while loop](/reference/loops/while), [for](/reference/loops/for), [boolean](/reference/types/boolean)

docs/reference/loops.md

@@ -2,7 +2,6 @@
 
 ```cards
 for(let i = 0;i<5;i++) {}
-for(let i = 1;i<5;i++) {}
 while(true) {}
 basic.forever(() => {})
 ```

docs/reference/loops/for.md

@@ -14,10 +14,6 @@ basic.showNumber(i)
 }
 ```
 
-### Lessons
-
-[looper](/lessons/looper)
-
 ### See also
 
 [repeat](/reference/loops/repeat), [while](/reference/loops/while), [if](/reference/logic/if), [show number](/reference/basic/show-number)

docs/reference/loops/repeat.md

@@ -6,10 +6,6 @@ Run part of the program the number of times you say.
 
 ![](/static/mb/blocks/contents-0.png)
 
-### Lessons
-
-[looper](/lessons/looper)
-
 ### See also
 
 [for](/reference/loops/for), [while](/reference/loops/while), [if](/reference/logic/if), [show number](/reference/basic/show-number)

docs/reference/loops/while.md

@@ -26,10 +26,6 @@ while(index >= 0) {
 }
 ```
 
-### Lessons
-
-[rotation animation](/lessons/rotation-animation)
-
 ### See also
 
 [on button pressed](/reference/input/on-button-pressed), [for](/reference/loops/for), [if](/reference/logic/if), [forever](/reference/basic/forever)

docs/reference/math/math.md

@@ -42,10 +42,6 @@ returns a random [Number](/reference/types/number) between 0 and the parameter *
 
 ![](/static/mb/blocks/math-3.png)
 
-### Lessons
-
-[love meter](/lessons/love-meter)
-
 ### See also
 
 [Block Editor documentation](/blocks/contents), [Number](/reference/types/number)

docs/reference/radio/on-data-received.md

@@ -7,6 +7,10 @@ Run part of a program when the micro:bit receives a
 
 * the part of the program to run when the micro:bit receives information over ``radio``.
 
+### Simulator
+
+This function only works on the micro:bit, not in browsers.
+
 ### Example
 
 This program keeps sending numbers that says how fast the micro:bit is

docs/reference/radio/receive-number.md

@@ -2,10 +2,14 @@
 
 Receives the next number sent by a micro:bit in the same ``radio`` group.
 
-### Return value
+### Returns
 
 * the first  [number](/reference/types/number) that the micro:bit received. If it did not receive any numbers, this function will return `0`.
 
+### Simulator
+
+This function only works on the micro:bit, not in browsers.
+
 ### Example: Simple number receiver
 
 This example receives the number broadcasted another micro:bit and shows it

docs/reference/radio/receive-string.md

@@ -6,10 +6,14 @@ Find the next string sent by `radio` from another micro:bit.
 radio.receiveString()
 ```
 
-### Return value
+### Returns
 
 * the first [string](/reference/types/string) that was sent. If no string was sent, then this function returns an empty (blank) string.
 
+### Simulator
+
+This function only works on the micro:bit, not in browsers.
+
 ### Example: Simple receiver
 
 Show the string sent by another micro:bit.

docs/reference/radio/received-signal-strength.md

@@ -0,0 +1,36 @@
+# Received Signal Strength
+
+Find how strong the ``radio`` signal is, from `255` to `0`.
+(`255` means a weak signal and `0` means a strong one.)
+
+The micro:bit finds the signal strength by checking how strong it was
+the last time it ran the
+[receive number](/reference/radio/receive-number) function. That means
+it needs to run **receive number** first.
+
+### Returns
+
+* a [number](/reference/types/number) between `255` and `0` that means
+how strong the signal is.
+
+### Simulator
+
+This function only works on the micro:bit, not in browsers.
+
+### Example
+
+This example shows how strong the radio signal of the
+[light level sender example](/reference/input/send-number) is.
+
+```blocks
+let x = 0;
+radio.setGroup(99);
+basic.forever(() => {
+    x = radio.receiveNumber();
+    basic.showNumber(radio.receivedSignalStrength());
+});
+```
+
+### See also
+
+[receive number](/reference/radio/receive-number), [send number](/reference/radio/send-number), [on data received](/reference/radio/on-data-received)

docs/reference/radio/send-number.md

@@ -6,6 +6,10 @@ Broadcast a number to other micro:bits connected via ``radio``.
 
 * num - a number to send.
 
+### Simulator
+
+This function only works on the micro:bit, not in browsers.
+
 ### Example: Broadcasting acceleration
 
 This example broadcasts the value of your micro:bit's ``acceleration`` in the `x` direction 

docs/reference/radio/send-string.md

@@ -1,7 +1,5 @@
 # Send String
 
-
-
 Sends a string to other micro:bits in the area connected by radio.
 
 ```sig
@@ -12,6 +10,12 @@ radio.sendString("Hello!")
 
 * `text` is a [String](/reference/types/string) to send by radio.
 
+### Simulator
+
+This function only works on the micro:bit, not in browsers.
+
+
+
 ### Example: Two-way radio
 
 If you load this program onto two or more micro:bits, you can send a code word from one of them to the others by pressing button `A`.

docs/reference/radio/set-group.md

@@ -14,6 +14,10 @@ to talk to each other because they will have the same group ID.
 
 * ``id`` is a [number](/reference/types/number) from ``0`` to ``255``.
 
+### Simulator
+
+This function only works on the micro:bit, not in browsers.
+
 ### Example
 
 This program makes the group ID equal 128.

docs/reference/radio/set-transmit-power.md

@@ -8,7 +8,7 @@ The scientific name for the strength of the ``radio`` signal is
 can be measured as -30 dBm, and a strength of `7` can be
 measured as +4 dBm.
 
-## Range
+### Range
    
 If your micro:bit is sending with a strength of `7`, and you are in
 an open area without many other computers around, the micro:bit signal
@@ -19,6 +19,10 @@ can reach as far as 70 meters (about 230 feet).
 * a [number](/reference/types/number) between ``0`` and ``7`` that
 means how strong the signal is.
 
+### Simulator
+
+This function only works on the micro:bit, not in browsers.
+
 ### Example
 
 This program makes the ``radio`` send at full strength.

docs/reference/radio/write-value-to-serial.md

@@ -9,21 +9,11 @@ The format for received data printed to serial is as follows
 - [send value](/reference/radio/send-number) - ```{v:Value,t:MicrobitTimeAlive,s:Unused,n:"Name"}```
 - [send string](/reference/radio/send-string) - ```{}``` (currently unavailable)
 
-## Important Security Consideration
 
-The functions in the ``radio`` namespace allow the BBC micro:bit to communicate with other micro:bits.
 
-This API does not contain any form of encryption, authentication or authorization. It's purpose is solely for use as a teaching aid to demonstrate how simple communications operates, and to provide a sandpit through which learning can take place.
+### Simulator
 
-For serious applications, BLE should be considered a substantially more secure alternative.
-
-```sig
-radio.writeValueToSerial()
-```
-
-### Parameters
-
-* None
+This function only works on the micro:bit, not in browsers.
 
 ### Examples
 

docs/reference/types/boolean.md

@@ -98,10 +98,6 @@ if(x < 5) {
 
 See the documentation on [Numbers](/reference/types/number) for more information on comparing two Numbers. You can also [compare strings](/reference/types/string-functions) using the `equals` function.
 
-### Lessons
-
-[rotation animation](/lessons/rotation-animation), [love meter](/lessons/love-meter), [zoomer](/lessons/zoomer)
-
 ### See also
 
 [if](/reference/logic/if), [while](/reference/loops/while), [number](/reference/types/number)

docs/reference/types/number.md

@@ -51,10 +51,6 @@ The [math library](/reference/math) includes math related functions. In the [Blo
 
 ![](/static/mb/blocks/number-3.png)
 
-### Lessons
-
-[game counter](/lessons/game-counter), [love meter](/lessons/love-meter)
-
 ### See also
 
 [math library](/reference/math), [var](/reference/variables/var), [Boolean](/reference/types/boolean), [show number](/reference/basic/show-number)

docs/reference/types/string.md

@@ -34,10 +34,6 @@ Use [show string](/reference/basic/show-string) to display a string on the [LED
 
 The  parameter of `show string` specifies the string
 
-### Lessons
-
-[glowing pendulum](/lessons/glowing-pendulum), [zoomer](/lessons/zoomer), [temperature](/lessons/temperature)
-
 ### See also
 
 [variables](/reference/variables/var), [string functions](/reference/types/string-functions), [Number](/reference/types/number), [show string](/reference/basic/show-string)

docs/reference/variables/assign.md

@@ -30,10 +30,6 @@ You can use the assignment operator with variables of
 every [type](/reference/types). A *type* is which kind of thing
 a variable can store, like a number or string.
 
-### Lessons
-
-[rotation animation](/lessons/rotation-animation)
-
 ### See also
 
 [variable](/reference/variables/var), [types](/reference/types)

docs/reference/variables/var.md

@@ -81,10 +81,6 @@ if (led.brightness() > 128) {
 
 * You can use the default variable names if you'd like, however, it's best to use descriptive variable names. To change a variable name in the editor, select the down arrow next to the variable and then click "new variable".
 
-### Lessons
-
-[glowing pendulum](/lessons/glowing-pendulum), [love meter](/lessons/love-meter), [temperature](/lessons/temperature), [zoomer](/lessons/zoomer)
-
 ### See also
 
 [types](/reference/types), [assignment operator](/reference/variables/assign)

docs/uploader.md

@@ -2,7 +2,7 @@
 
 ### ~avatar avatar
 
-The Uploader **automatically** deploys .hex files to all BBC micro:bit connected to your computer.
+The Uploader **automatically** deploys .hex files to all micro:bits connected to your computer.
 
 ## [DOWNLOAD](https://www.pxt.io/microbit-uploader.zip)
 
@@ -12,8 +12,8 @@ The Uploader **automatically** deploys .hex files to all BBC micro:bit connected
 
 ### Works with any browser!
 
-The uploader monitors your Downloads folder looking for any .hex file being download. 
-When it detects a new .hex file, the uploader tries to copy it to all connected BBC micro:bits (it copies it to the MICROBIT drives). 
+The uploader monitors your Downloads folder looking for any .hex file that has been downloaded (saved from the browser). 
+When it detects a new .hex file, the uploader tries to copy it to all MICROBIT drives. 
 That's it!
 
 ![](/static/uploader/tooltip.png)

libs/microbit-bluetooth/README.md

@@ -0,0 +1 @@
+# Bluetooth services

libs/microbit-bluetooth/bluetooth.cpp

@@ -0,0 +1,15 @@
+#include "pxt.h"
+#include "MESEvents.h"
+
+using namespace pxt;
+//% color=#0082FB weight=2
+namespace bluetooth {
+    /**
+    *  Starts the Bluetooth IO pin service
+    */
+    //% help=bluetooth/io-pin-service
+    //% blockId=bluetooth-io-pin-service block="bluetooth io pin service"
+    void startIOPinService() {
+        new MicroBitIOPinService(*uBit.ble, uBit.io);
+    }
+}

libs/microbit-bluetooth/enums.d.ts

@@ -0,0 +1,5 @@
+// Auto-generated. Do not edit.
+declare namespace bluetooth {
+}
+
+// Auto-generated. Do not edit. Really.

libs/microbit-bluetooth/pxt.json

@@ -0,0 +1,24 @@
+{
+    "name": "microbit-bluetooth",
+    "description": "Bluetooth services",
+    "files": [
+        "README.md",
+        "enums.d.ts",
+        "shims.d.ts",
+        "bluetooth.cpp"
+    ],
+    "public": true,
+    "dependencies": {
+        "microbit": "file:../microbit"
+    },
+    "yotta": {
+        "config": {
+            "microbit-dal": {
+                "bluetooth": {
+                    "enabled": 1
+                }
+            }
+        }
+    },
+    "installedVersion": "bpcjjs"
+}

libs/microbit-bluetooth/shims.d.ts

@@ -0,0 +1,16 @@
+// Auto-generated. Do not edit.
+
+
+
+    //% color=#0082FB weight=2
+declare namespace bluetooth {
+
+    /**
+     *  Starts the Bluetooth IO pin service
+     */
+    //% help=bluetooth/io-pin-service
+    //% blockId=bluetooth-io-pin-service block="bluetooth io pin service" shim=bluetooth::startIOPinService
+    function startIOPinService(): void;
+}
+
+// Auto-generated. Do not edit. Really.

libs/microbit-devices/devices.cpp

@@ -204,7 +204,7 @@ namespace devices {
 
     /**
      * Registers code to run when the device notifies about a change of signal strength.
-     * @param body TODO
+     * @param body Code run when the signal strength changes.
      */
     //% weight=23 help=devices/on-signal-strength-changed
     //% blockId=devices_signal_strength_changed_event block="on signal strength changed" icon="\uf012"
@@ -213,4 +213,3 @@ namespace devices {
         registerWithDal(MES_SIGNAL_STRENGTH_ID, MICROBIT_EVT_ANY, body);
     }
 }
-

libs/microbit-devices/shims.d.ts

@@ -57,7 +57,7 @@ declare namespace devices {
 
     /**
      * Registers code to run when the device notifies about a change of signal strength.
-     * @param body TODO
+     * @param body Code run when the signal strength changes.
      */
     //% weight=23 help=devices/on-signal-strength-changed
     //% blockId=devices_signal_strength_changed_event block="on signal strength changed" icon="\uf012" shim=devices::onSignalStrengthChanged

libs/microbit/basic.cpp

@@ -29,8 +29,8 @@ namespace basic {
 
     /**
      * Draws an image on the LED screen.
-     * @param leds TODO
-     * @param interval TODO
+     * @param leds the pattern of LED to turn on/off
+     * @param interval time in milliseconds to pause after drawing
      */
     //% help=basic/show-leds 
     //% weight=95 blockGap=8
@@ -77,8 +77,8 @@ namespace basic {
 
     /**
      * Shows a sequence of LED screens as an animation.
-     * @param leds TODO
-     * @param interval TODO
+     * @param leds pattern of LEDs to turn on/off
+     * @param interval time in milliseconds between each redraw
      */
     //% help=basic/show-animation imageLiteral=1 async
     void showAnimation(ImageLiteral leds, int interval = 400) {
@@ -87,7 +87,7 @@ namespace basic {
 
     /**
      * Draws an image on the LED screen.
-     * @param leds TODO
+     * @param leds pattern of LEDs to turn on/off
      */
     //% help=basic/plot-leds weight=80
     void plotLeds(ImageLiteral leds) {
@@ -104,7 +104,7 @@ namespace basic {
 
     /**
      * Repeats the code forever in the background. On each iteration, allows other codes to run.
-     * @param body TODO
+     * @param body code to execute
      */
     //% help=basic/forever weight=55 blockGap=8
     //% blockId=device_forever block="forever" icon="\uf01e"

libs/microbit/music.ts

@@ -159,7 +159,7 @@ namespace music {
      * Change the tempo by the specified amount
      * @param bpm The change in beats per minute to the tempo, eg: 20
      */
-    //% help=music/tempo weight=39
+    //% help=music/change-tempo weight=39
     //% blockId=device_change_tempo block="change tempo by (bpm)|%value" blockGap=8
     export function changeTempoBy(bpm: number): void {
         setTempo(beat(BeatFraction.Whole) + bpm);
@@ -169,7 +169,7 @@ namespace music {
      * Sets the tempo to the specified amount
      * @param bpm The new tempo in beats per minute, eg: 120
      */
-    //% help=music/tempo weight=38
+    //% help=music/set-tempo weight=38
     //% blockId=device_set_tempo block="set tempo to (bpm)|%value"
     export function setTempo(bpm: number): void {
         init();