RC car lesson (#519)

* initial drop

* fixing summary

* adding images

* Adding basic connect code

* connect section

* moving video

* adding ignores

docs/SUMMARY.md

@@ -30,6 +30,7 @@
     * [Inchworm](/projects/inchworm)
     * [Milk Carton Robot](/projects/milk-carton-robot)
     * [Milk monster](/projects/milky-monster)
+    * [RC Car](/projects/rc-car)
     * [Timing gates](/projects/timing-gates)
     * [Compass](/projects/compass)
     * [Telegraph](/projects/telegraph)

docs/projects.md

@@ -110,6 +110,10 @@ Fun games to build with your @boardname@.
   "name": "Railway crossing",
   "url":"/projects/railway-crossing",
   "imageUrl":"/static/mb/projects/railway-crossing.png"
+},{
+  "name": "Hacked RC car with Kitronik",
+  "url": "/projects/rc-car",
+  "imageUrl":"/static/mb/projects/rc-car.jpg"
 }]
 ```
 

docs/projects/rc-car.md

@@ -0,0 +1,54 @@
+# RC car
+
+### ~avatar avatar
+
+Hack a toy RC car with your @boardname@!
+
+### ~
+
+https://youtu.be/xQJCZwVvjyw
+
+### ~ hint
+
+This activity involves opening an electronic toy, cutting into cables and potentially rendering it completly useless.
+
+### ~
+
+## Materials
+
+* Toy RC car with 4 or 6 AA batteries
+* 1 @boardname@
+* a cable trimmer
+* small Philips screw driver
+* [1 Kitronik motor driver](https://www.kitronik.co.uk/5620-motor-driver-board-for-the-bbc-microbit-v2.html)
+
+## What's the plan?
+
+Most toy RC car use 3 small DC motors to operate:
+* 1 DC motor for the back wheels torque,
+* 1 DC motor for the front wheels torque,
+* 1 DC motor to steer the front wheels
+
+The plan is to open up the RC car, remove the existing electronic controller and replace it with the motor driver
+that can control 2 DC motors. We will connect both torque motors to one controller and the steering motor to the other controller.
+
+Once the motor driver is connected, we will use a @boardname@ to control it. Another @boardname@ can also be used as a radio controller
+for the @boardname@ in the car.
+
+### ~ hint
+
+Ask friends and family for old RC cars lying around, scout thrift shops and other second hand shops for discarded RC cars.
+
+### ~
+
+## Activities
+
+* [Make](/projects/rc-car/make)  
+* [Code](/projects/rc-car/code)
+* [Connect](/projects/rc-car/connect)
+
+### ~button /projects/rc-car/make
+
+Let's make it!
+
+### ~

docs/projects/rc-car/code.md

@@ -0,0 +1,72 @@
+# Code
+
+## Step 1: Add the Kitronik package
+
+Kitronik published a set of blocks to use their motor driver. We need to add it to our project.
+
+* Click on **Advanced**
+* Click **Add Package**
+* Type ``kitronik``, press **Enter**
+* Select the **kitronik-motor-driver** package
+
+After the package gets loaded, you should see a new **Kitronik" category in the toolbox.
+
+## Step 2: Round and round we go!
+
+https://youtu.be/pD6tM1nXCPA
+
+The first program will have the car drive in a circle for 5 seconds when the user presses button ``A``. 
+This is simply done by turning both motor controllers on for 5 seconds.
+
+```blocks-ignore
+input.onButtonPressed(Button.A, () => {
+    basic.showIcon(IconNames.Happy)
+    kitronik.motorOn(kitronik.Motors.Motor1, kitronik.MotorDirection.Reverse, 100)
+    kitronik.motorOn(kitronik.Motors.Motor2, kitronik.MotorDirection.Forward, 100)
+    basic.pause(5000)
+    kitronik.motorOff(kitronik.Motors.Motor1)
+    kitronik.motorOff(kitronik.Motors.Motor2)
+    basic.showIcon(IconNames.SmallDiamond)
+})
+```
+
+### ~ hint
+
+Make sure to unplug the @boardname@ from the Edge connector while your are connecting it to your computer to avoid any kind of electrical problem.
+
+### ~
+
+Depending on how you've connected your cables to the motor driver, your car may be going backward instead of forward. 
+You can either swap the cables or change your code to account for that.
+
+## Step 3: Figure Eight
+
+https://youtu.be/agor9wtiAkE
+
+Instead of stopping after 5 seconds, we reverse the steering motor to turn the other direction. This will create a figure eight trajectory.
+
+```blocks-ignore
+input.onButtonPressed(Button.A, () => {
+    basic.showIcon(IconNames.Happy)
+    kitronik.motorOn(kitronik.Motors.Motor1, kitronik.MotorDirection.Reverse, 100)
+    kitronik.motorOn(kitronik.Motors.Motor2, kitronik.MotorDirection.Forward, 100)
+    basic.pause(3500)
+    kitronik.motorOn(kitronik.Motors.Motor2, kitronik.MotorDirection.Reverse, 100)
+    basic.pause(3500)
+    kitronik.motorOff(kitronik.Motors.Motor1)
+    kitronik.motorOff(kitronik.Motors.Motor2)
+    basic.showIcon(IconNames.SmallDiamond)
+})
+```
+
+Great! It's now time to use another @boardname@ to remove control the car.
+
+### ~button /projects/rc-car/connect
+
+Connect
+
+### ~
+
+```package
+pxt-kitronik-motor-driver=github:kitronikltd/pxt-kitronik-motor-driver#v0.0.3
+```

docs/projects/rc-car/connect.md

@@ -0,0 +1,54 @@
+# Connect
+
+
+https://youtu.be/XXesoUC0XBU
+
+We are going to use radio to remote control the toy car. 
+A second @microbit@ will send commands to control the throttle and the steering.
+
+```blocks-ignore
+let steering = 0
+let throttle = 0
+radio.onDataPacketReceived( ({ receivedString: name, receivedNumber: value }) =>  {
+    led.toggle(0, 0)
+    if (name == "throttle") {
+        if (value > 0) {
+            kitronik.motorOn(kitronik.Motors.Motor1, kitronik.MotorDirection.Reverse, 100);
+        } else if (value < 0) {
+            kitronik.motorOn(kitronik.Motors.Motor1, kitronik.MotorDirection.Forward, 100);
+        } else {
+            kitronik.motorOff(kitronik.Motors.Motor1);
+        }
+    } else if (name == "steering") {
+        if (value > 0) {
+            kitronik.motorOn(kitronik.Motors.Motor2, kitronik.MotorDirection.Forward, 100);
+        } else if (value < 0) {
+            kitronik.motorOn(kitronik.Motors.Motor2, kitronik.MotorDirection.Reverse, 100);
+        } else {
+            kitronik.motorOff(kitronik.Motors.Motor2);
+        }
+    }
+})
+basic.forever(() => {
+    throttle = 0
+    if (input.buttonIsPressed(Button.A)) {
+        throttle = 100
+    } else if (input.buttonIsPressed(Button.B)) {
+        throttle = -100
+    }
+    radio.sendValue("throttle", throttle)
+    steering = 0
+    if (input.acceleration(Dimension.X) < -512) {
+        steering = -100
+    } else if (input.acceleration(Dimension.X) > 512) {
+        steering = 100
+    }
+    radio.sendValue("steering", steering)
+})
+radio.setGroup(12)
+```
+
+```package
+radio
+pxt-kitronik-motor-driver=github:kitronikltd/pxt-kitronik-motor-driver#v0.0.3
+```

docs/projects/rc-car/make.md

@@ -0,0 +1,76 @@
+# Make
+
+### @description Hacking the car electronics
+
+### ~avatar avatar
+
+Hack the @boardname@ into the car!
+
+### ~
+
+https://youtu.be/gH__3l_oDeM
+
+## Materials
+
+* a toy RC car with 4 or 6 AA batteries
+* a cable trimmer
+* small Philips screw driver
+
+![A toy RC car](/static/mb/projects/rc-car/rccar.jpg)
+
+## Step 1: Remove the batteries!
+
+Make sure all the batteries are removed from the toy car!
+
+## Step 2: Remove the cover
+
+Remove the various protective covers until you have access to the electronic controller. Make sure to keep track of all the screws you remove, 
+you will need them again!
+
+## Step 3: Cut out the electronic board
+
+Follow the motor and power cables and cut the wires as close as possible from the electronic board. You should end up with a total of 8 cables:
+2 for power, 2 for the steering motor and 2 pairs for the torque motors.
+
+![Electronic board removed](/static/mb/projects/rc-car/elecremoved.jpg)
+
+## Step 4: Prepare the cables
+
+Using the wire trimmer, expose 1/4 inch (1/2 cm) of metal on each wire so you can attach it to the motor driver.
+
+![Various cables](/static/mb/projects/rc-car/cables.jpg)
+
+## Step 5: Connect the battery cables
+
+* Connect the cables from the battery section to the power input on the motor shield. 
+Make sure the **+** cable goes into the **+** port!
+* Connect both torque motors to the **motor 1** connector in the motor driver. 
+Make sure to connect the cables of same colors so that your wheel turn the same direction!
+* Connect the remaining motor cables to the **motor 2** connector.
+
+![Wiring](/static/mb/projects/rc-car/wiring.jpg)
+
+## Step 6: Slot in the @boardname@
+
+Probably the easiest step, insert the @boardname@ in the edge connector until clips in.
+
+## (Optional) Step 7: Cut out a slot in the cover to fit the @boardname@
+
+Depending on your car size, you may be able to fit back the decoration top back on the car. 
+Otherwise, get some cardboard, scissors and a glue gun to rebuild it yourself!
+
+![Cutout](/static/mb/projects/rc-car/cutout.jpg)
+
+## (Optional) Step 8: Paint job
+
+Once you have replaced the cover (original or carboard), decorate it to your taste!
+
+![Painted](/static/mb/projects/rc-car/painted.jpg)
+
+That's it, it's time to code!
+
+### ~button /projects/rc-car/code
+
+Code
+
+### ~