Merge branch 'master' of https://github.com/Microsoft/pxt-microbit

docs/getting-started.md

@@ -147,6 +147,13 @@ input.onButtonPressed(Button.A, () => {
 });
 ```
 
+#### ~hint
+
+The ``showString`` block can show letters, numbers, and punctuation
+on the micro:bit screen.
+
+#### ~
+
 Now try to unscramble these blocks in the editor so that the micro:bit
 shows **banana** when you press button `B`.
 
@@ -160,10 +167,13 @@ input.onButtonPressed(Button.B, () => {
 You can find the letter `B` by clicking the letter `A` on the
 ``onButtonPressed`` block.
 
-#### 
+#### ~
 
-Can you combine these blocks so your program shows **anteater** when
-you press `A`, but **banana** when you press `B`?
+#### Your turn!
+
+Can you combine these blocks so your program shows your real name
+instead of **anteater** when you press `A`, but _your secret agent
+name_ instead of **banana** when you press `B`?
 
 ### Shake
 

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

@@ -5,14 +5,14 @@ Run part of a program when the micro:bit receives a
 
 ### Parameters
 
-* **body** is the part of the program to run when the micro:bit receives information over ``radio``.
+* the part of the program to run when the micro:bit receives information over ``radio``.
 
 ### Example
 
-This program never stops.  It keeps sending numbers that says how
-fast the micro:bit is slowing down or speeding up.  It also receives
-numbers that say how fast nearby micro:bits are going. It
-shows these numbers as a [bar graph](/reference/led/plot-bar-graph).
+This program keeps sending numbers that says how fast the micro:bit is
+slowing down or speeding up.  It also receives numbers for the same
+thing from nearby micro:bits. It shows these numbers as a
+[bar graph](/reference/led/plot-bar-graph).
 
 ```blocks
 basic.forever(() => {

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

@@ -1,33 +1,27 @@
 # Set Transmit Power
 
-Sets the transmitter power for ``radio`` communications.    
-The power can be set to a value between 0 (-30dbm) and 7 (+4dbm).
+Make the ``radio`` signal of the micro:bit stronger or weaker.
+It can be as weak as `0` and as strong as `7`.
+
+The scientific name for the strength of the ``radio`` signal is
+**dBm**, or **decibel-milliwatts**. A signal strength of `0`
+can be measured as -30 dBm, and a strength of `7` can be
+measured as +4 dBm.
 
 ## Range
    
-At power level 7, in an open area without significant interference (coming from WiFi networks or other devices operating on the 2.4 GHz range), you can get a **range of over 70m**.   
- 
-Indoors (or with additional interference), range will be significantly reduced.
-
-## 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.
-
-For serious applications, BLE should be considered a substantially more secure alternative.
-
-```sig
-radio.setTransmitPower(1)
-```
+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
+can reach as far as 70 meters (about 230 feet).
 
 ### Parameters
 
-* ``power`` -- a [number](/reference/types/number) between ``0`` and ``7``.
+* a [number](/reference/types/number) between ``0`` and ``7`` that
+means how strong the signal is.
 
 ### Example
 
-Sets the transmitter power to full power at 7.
+This program makes the ``radio`` send at full strength.
 
 ```blocks
 radio.setTransmitPower(7)