File content as of revision 0:41ca27337c2b:

// Firmware to demonstrate typical "Tank-Drive" robot motor control.
// one left motor, and one right motor.
//
// Can do simple commanding from a bluetooth terminal (like Android's BlueTerm),
// or from the Android app used in http://www.instructables.com/id/Simple-RC-car-for-beginners-Android-control-over-/
//
// The FreeScale FRDM-K64F is a much more powerful board than needed for this task,
// but it is a good template for a typical "tank-drive" robot based on the FRDM-K64F.

#include "mbed.h"

//DigitalOut gpo(D0);
//DigitalOut led(LED_RED);
//PwmOut ENA( PTD1);   // D13 on Arduino Shield
//PwmOut IN1A(PTD3);  // D12 on Arduino Shield
//PwmOut IN2A(PTD2);  // D11 on Arduino Shield
//PwmOut ENB( PTD0);   // D13 on Arduino Shield
//PwmOut IN1B(PTC4);  // D12 on Arduino Shield
//PwmOut IN2B(PTA0);  // D11 on Arduino Shield

Timer Time;
inline int millis() {return(Time.read_ms());} // mimic Arduino millis() function

// Tried to inherit/polymorph serial capabilities...  but could
// not get to compile... or get access to mbed::stream capabilities.
// I know this is sloppy...  but I'm just going to make a global
// Serial, and let otherclasses have a reference to it.
#include "Serial.h"
//Serial CmdSerial(PTC17,PTC16);  // Command/Diagnostic serial port on UART3, sicne I don't know how to use USB ports (yet)
Serial CmdSerial(PTC15,PTC14);  // Command/Diagnostic serial port on "bluetooth add-on" header

#include "ASerial.h"  // emulation of some common Arduino Serial methods
ASerial cSerial(CmdSerial); 

// Set up motor drive for left and right motors
#include "MotorDriveDBH1.h"
MotorDrive MotL(PTD1,PTD3,PTD2,PTB2);
MotorDrive MotR(PTD0,PTC4,PTA0,PTB3);

#include "Command.h"

void initMotorDrive(MotorDrive &md)
{
    md.setCommandTimeout(5000);  // ms between commands before automatic emergency stop
    //ms.setPWMfreqHz(8000);
    
    // these should be the defaults
    //md.setStartupTime(5);  // full power pulse this long when starting from full STOP
    //md.setStopDeadTime(3000); // wait this many ms after emergency STOP before starting up again
    //md.setMinPWM(0.004f);  // any PWM command below this istreated as 0
    //md.setMaxPWM(0.98f);  // these drives can fail if attempt to run full-100%
    //md.setDecel(0.01f);  // deceleration rate on STOP.  This frac/ms
    
}
// make sure deadman release stops immediately
void deadmanReleased()
{
  MotR.emergencyStop();
  MotL.emergencyStop();
  cSerial.println("STOP");
}

// Since this board has fancy tri-color LED, let's sequence it
// instead of a boring old flash for a heartbeat
DigitalOut ledR(LED_RED);
DigitalOut ledG(LED_GREEN);
DigitalOut ledB(LED_BLUE);
void toggleFlash()
{
    static int k=0;
    k++;
    if ((k<0) || (k>7)) k=0;
    // Gray code counter...
    switch(k)
    {
        case 1:
        case 5:  ledG = !ledG; break;
        case 3:
        case 7:  ledB = !ledB; break;
        default: ledR = !ledR; break;
    }
}

void reportCurrent()
{
  float cr, cl;
  cr = MotR.getCurrent();
  cl = MotL.getCurrent();
  cSerial.print("Current:  left=");cSerial.print(cl);
  cSerial.print("   right=");cSerial.println(cr);
}

//void dumpSerialChar()
//{
//  int i = cSerial.getc();
//  CmdSerial.printf("%d %c\n",i,i);    
//}
    
// ================================================== main

int prevCommandTime=0;

#define FLASH_DT 800
int tFlash = 0;

// for diagnostics, just print a few messages, then be quiet to improve
// performance when in actual use.
int nMsg = 99;

int main()
{

    // Set motor drive parameters
    initMotorDrive(MotL);
    initMotorDrive(MotR);

    CmdSerial.baud(57600);
    CmdSerial.puts("\r\nTankDrive for K64F with Bluetooth\r\n\n");
    
    Time.reset();
    Time.start();

    CommandReader cmd(cSerial);
        
    while (true) {
        int t = Time.read_ms();

        char code;
        int val;
        int stat = cmd.get(code,val);
        if (stat)
        {
            prevCommandTime = t;
            if (nMsg>0){nMsg--;CmdSerial.printf(">%c%d\r\n",code,val);}
/*
            switch(code)
            {
            case 'L': MotL.setSpeed(val,t); break;
            case 'R': MotR.setSpeed(val,t); break;
            default : 
                MotL.setSpeed(0,t);  // odd command.  just stop
                MotR.setSpeed(0,t);
                CmdSerial.puts("<stop\r\n");
            }
*/
        }
        else
        { // no command, do housekeeping (misc state update stuff)
            //MotL.update(t);
            //MotR.update(t);

            if ((prevCommandTime > 0x0fffff00) && (t < 999))
            {  // time counter is close to wrapping around.  make sure this does not happen.
               // I think we can tolerate a minor glitch once every 24.8 days of continuous use
               prevCommandTime = tFlash = 0;
               Time.reset();
               Time.start();
               while(Time.read() < 1);
               t = 1;
            }
        
            if (t - tFlash > FLASH_DT)
            { // Flash standard LED to show things are running
                tFlash = t;
                CmdSerial.printf("dt=%d\r\n",t);
                toggleFlash();
                //reportCurrent();
                //wait(0.8f);
            }
        }
    }
}