Hello,
I have created a car with 4 motors, 2 motor controllers and 7,5v battery pack and Fez Panda II. All pieces are connected and when I run my project with visual studio USB connected (side by side with battery), everything works ok. When I remove the USB and run the project onchip with battery, behavior is not the same. The wheels just run on one direction. I’m noob with electronics (not with programming) but I can’t figure out the problem. I thought that this might be ground problem because it seems that the “high” digital IO does nothing. But still the same bahavior. I have also erased the board with MFDeploy to be sure that there is latest program on chip but still same results. I’m confused ::). Any ideas? Remember that I’m a noob so this might be really simple 
public static void Main()
{
while (true)
{
MotorController.Forward();
Thread.Sleep(1000);
MotorController.Reverse();
Thread.Sleep(1000);
MotorController.TurnLeftForward();
Thread.Sleep(1000);
}
}
MotorController.cs
public class MotorController
{
static byte speed = 100;
static PWM pwmRight = new PWM((PWM.Pin)FEZ_Pin.PWM.Di8);
static OutputPort directionRight = new OutputPort((Cpu.Pin)FEZ_Pin.Digital.Di20, false);
static PWM pwmLeft = new PWM((PWM.Pin)FEZ_Pin.PWM.Di6);
static OutputPort directionLeft = new OutputPort((Cpu.Pin)FEZ_Pin.Digital.Di24, false);
public static void Stop()
{
pwmRight.Set(19200 * 1000, 0);
pwmLeft.Set(19200 * 1000, 0);
Thread.Sleep(3000);
}
public static void Forward()
{
Stop();
directionRight.Write(true);
directionLeft.Write(false);
pwmRight.Set(19200 * 1000, speed);
pwmLeft.Set(19200 * 1000, speed);
}
public static void TurnLeftForward()
{
Stop();
directionRight.Write(false);
directionLeft.Write(false);
pwmRight.Set(19200 * 1000, speed);
pwmLeft.Set(19200 * 1000, speed);
Thread.Sleep(2000);
Stop();
}
public static void TurnRightForward()
{
Stop();
directionLeft.Write(true);
directionRight.Write(true);
pwmRight.Set(19200 * 1000, speed);
pwmLeft.Set(19200 * 1000, speed);
Thread.Sleep(2000);
Stop();
}
public static void Reverse()
{
Stop();
directionRight.Write(false);
directionLeft.Write(true);
pwmRight.Set(19200 * 1000, speed);
pwmLeft.Set(19200 * 1000, speed);
}
}