To control the machine using 4 different way:
- Accelerometer. Tilt forward - car goes forward, tilt to the left - car turns to the left, tilt back - car goes back. Speed of movement or rotation depends on how much you tilt the device. Sensitivity and value of the tilt set in the configuration Android-apps.
- On-Screen Buttons.
- Touch Control via virtual circle.
- Wheel Control - like virtual steering wheel.
Step 1: Assembly
Step 2: Parts
Also you need any .NET Micro Framework board, Chassis, Bluetooth module (i'm use HC-06) and L298N Dual Bridge DC stepper Motor Driver module
Step 3: Calculations and Block Diagram
L - the command to the left engine, R - for the right
A dash means the motor rotation to move back
255 - PWM value (for Arduino is the maximum speed of rotation)
\r - end of command.
On this command RC car will move forward and slightly rotated to the right, as right engine rotates slowly left.
On this command the left engine will rotate back and forward right, forcing a car to rotate around its axis counterclockwise.
Command is an additional channel to which you can connect for example lights, sound, etc.
Symbols command L, R and H can be defined in the settings of Android-applications.
In the MCU control program provides a timer that shuts off the engine if the last command was received more than n-seconds ago. The data are stored in the EEPROM memory of the controller and can be changed from Android device. The range of this setting is from 0.1 seconds to 99.9 seconds. This setting can be disabled. To work with EEPROM provides commands: Fr - reading values and Fw - record values.
Step 4: Android Application
The application contains several activity. Main activity is a home screen with buttons running different operating modes and settings
To establish a connection with the RC Car's Bluetooth module, you must set MAC-address in the application settings. But first, you must configure the pair the devices on Android-device: open Settings -> Bluetooth and click "Search for devices". When the phone finds our Bluetooth-module, click them and enter password for pairing (usually "1234")
To know Bluetooth module MAC-address possible from any application, such as Bluetooth Terminal. To do this, click "Connect a device - Secure" and in the resulting window, click the button "Scan for devices". Software will be scans the Bluetooth devices and displays them MAC-address.
Step 5: Assembly
Power DC motors are from the 3xLi-Po battery 3.7V 1100 mAh. The controller is powered by a single 3.7V Li-Po battery (although the required 5V, but works fine on 3.7V). Power supply of Bluetooth module is taken from the FEZ board.