New guitar project (#264)

2016-09-26 21:55:39 -07:00
parent c486a9db94
commit 2c39e249f9
19 changed files with 632 additions and 0 deletions
--- a/docs/projects/guitar/accelerometer.md
+++ b/docs/projects/guitar/accelerometer.md
@ -0,0 +1,114 @@
+# Accelerometer Beat control
+
+### @description micro:bit guitar: using accelerometer to control tempo
+
+### ~avatar avatar
+
+Use the Accelerometer to control guitar tempo
+* Duration: 30 - 45 minutes
+* Concepts:
+     * Gravity
+     * Acceleration
+     * X, Y, Z coordinates
+     * Tempo
+     * Beat
+     * Mapping
+     * Graphing
+     * Absolute value
+
+### ~  
+
+*accelerometer controlled tempo*  
+https://youtu.be/h_gPkBaVkoo
+TODO: add sound to video
+## Blocks
+
+```cards
+input.acceleration(Dimension.Y)
+music.setTempo(120)
+pins.map(0, 0, 1023,60, 320)
+Math.abs(1)            
+```
+
+## Accelerometer, gravity and tilting!
+
+The micro:bit contains an **accelerometer** sensor that is able to measure forces applied to the board.
+On earth, we are subject to the **gravity force** which pulls us to the ground!
+
+https://youtu.be/0SULoTKmkhI
+
+When the micro:bit is flat on a table, with the screen pointing up, the gravity force is aligned
+with the **Z** axis of the micro:bit. 
+
+![micro:bit x, y, z axis image](/static/mb/projects/guitar/accelleration_axis.png)  
+
+If you tilt it up and down, the force will align with the **Y** axis -- this is how we can detect tilting!!!
+If the force along **Y** grows, the micro:bit is tilting more and more vertically!
+
+## Measuring Acceleration along different coordinates (X, Y, Z axis)  
+
+The acceleration block approximately measures **milli-g**, which is 1/1000 of a **g** or the 
+acceleration of gravity. 
+
+### Step 1: Graphing acceleration 
+```blocks
+basic.forever(() => {
+    led.plotBarGraph(input.acceleration(Dimension.Y), 1023)
+})
+```
+**Create the code** that measures the change in the Y axis acceleration as a graph on the LEDs  
+  
+**Dowload the code** to the micro:bit 
+  
+**Test the movements that move the graph from 1 to 5 bars on the LEDs** 
+
+### Extra
+
+Try graphing the acceleration along the **X** and **Z** axis. Can you explain the differences?
+
+### ~hint  
+## Mapping  
+**It is common to map one standard to another - such as with temperature**  
+![Fahrenheit to Celsius](/static/mb/projects/guitar/map_analogy.png "Fahrenheit to Celsius")  
+### ~
+
+### Step 2: Mapping acceleration to Beat
+**micro:bit sensors produce signal values between 0 to 1023. The *[map block](/reference/pins/map)* converts the signal to a desired range.**    
+```blocks
+basic.forever(() => {
+        music.setTempo(pins.map(Math.abs(input.acceleration(Dimension.Y)),
+            0, 1023,
+            60, 320))
+         music.playTone(Note.C, music.beat(BeatFraction.Quarter));
+})
+```  
+
+**Create the code** that *Maps*  Y axis acceleration as *tempo*  
+  
+**Download the code** to the micro:bit on the guitar  
+  
+**Test the movements that speed and slow the tempo**  
+
+### Step 3: Combine with light sensor tone control  
+**Put it all together!**
+
+```blocks
+basic.forever(() => {
+        music.setTempo(pins.map(Math.abs(input.acceleration(Dimension.Y)),
+            0, 1023,
+            60, 320))
+        music.playTone(
+            input.lightLevel() * 25,
+            music.beat(BeatFraction.Quarter)
+        );
+})
+```  
+**Combine the code above with the light sensor tone control code from the previous activity**
+  
+**Download the code** to the micro:bit on the guitar    
+
+###  Now play the guitar adjusting tone and tempo using the light sensor and accelerometer!
+
+### ~button /projects/guitar/pinpress
+NEXT: Pin Press on/off
+### ~