Next, you'll need to fasten the relay module with a screw to the base and solder or jumper wires from the two input pins on the relay module to pins 2 and 14 of the Launchpad headers.

The two through holes beside the USB connector on the Launchpad are Ground and 5V/6V. These should be connected to the battery holder and this 6V should also be connected to the one side of each motor. The other side of each motor should be connected to each of the power relays with the normally open(NO) side connected to ground.

The assembled system will look like this:

Next, you will need to program your Launchpad via the provided USB cable with the REKAM1 Virtual Machine. The project code can be found here:

Instructions on how to import and existing project and flash your Launchpad can be found here:

Next, we need to make some modifications to the BlueRadios example. First we need to ensure the module is set to data mode:

     ! Set the mode to data mode.

     ! value = [2]

     value = [1]

Next, we want to use the accelerometer to enable us to control the drone, so we'll need to initiate this sensor:

! Let the user type a command, sending it to RX.


 a = sensors.accel

Next, we want to initialize both wheels on the car to a pulsed output percentage on time of zero:

 line$ = "put 2 0\n"

 line2$ = "put 14 0\n"

We need to send the newline character(\n) above so that REKAM1 knows this is a separate command. We're going to send two lines of code at a time since there are two wheels to control. Next we write a condition for moving forward:

 IF a(2) > .40 THEN

 line$="put 2 70\n"

 line2$="put 14 70\n"     



In the above, we are checking to see if the magnitude of the accelerometer in the second of three dimensions exceeds some threshold. As we tilt our iOS device, the magnitude of accelerometer values will change depending on how much of that component is aligned with gravity. (we're always accelerating down) We can now add conditions to turn off either the left or right motor when we also tilt the iOS device left or right:

 IF a(1) < -.2 THEN

   line$ = "put 2 0\n"


 ELSE IF a(1) > .2 THEN

   line2$ = "put 14 0\n"



Finally, we need to add some code to send a second line of code(line2$) so that the left and right wheels are actuated for every program loop. This code converts the text message we want to send into an integer array that we then write as a characteristic over our Bluetooth Low Energy Peripheral connection:

   DIM line%(LEN(line2$) + 1)

   FOR i = 1 TO LEN(line2$)

   line%(i) = ASC(MID(line2$, i, 1))


   line%(UBOUND(line%, 1)) = 13

   blueRadiosPeripheral.writeCharacteristic(ch, line%, 1)

You can see some videos of a text messaging robot game with a similar smart car kit I put together for a Kickstarter here:

The complete techBasic code described above can be found here(and in future releases of techBasic): SmartCar.bas

This kit basically integrates an MSP430 with some PowerFets, a BlueRadio module, a Smart Car kit, 50 K'nex pieces, some sensor and servo attachments with a modifiable robot game written in techBasic!  I developed this kit and game to make learning about programming truly fun. Enjoy!