File content as of revision 6:4edbe75736d9:

#include "mbed.h"
#include "rtos.h"
#include <string>

//Photointerrupter input pins
#define I1pin D2
#define I2pin D11
#define I3pin D12

//Incremental encoder input pins
#define CHA   D7
#define CHB   D8

//Motor Drive output pins   //Mask in output byte
#define L1Lpin D4           //0x01
#define L1Hpin D5           //0x02
#define L2Lpin D3           //0x04
#define L2Hpin D6           //0x08
#define L3Lpin D9           //0x10
#define L3Hpin D10          //0x20

//Define sized for command arrays
#define ARRAYSIZE 8

//Mapping from sequential drive states to motor phase outputs
/*
State   L1  L2  L3
0       H   -   L
1       -   H   L
2       L   H   -
3       L   -   H
4       -   L   H
5       H   L   -
6       -   -   -
7       -   -   -
*/
//Drive state to output table
const int8_t driveTable[] = {0x12,0x18,0x09,0x21,0x24,0x06,0x00,0x00};

//Mapping from interrupter inputs to sequential rotor states. 0x00 and 0x07 are not valid
const int8_t stateMap[] = {0x07,0x05,0x03,0x04,0x01,0x00,0x02,0x07};
//const int8_t stateMap[] = {0x07,0x01,0x03,0x02,0x05,0x00,0x04,0x07}; //Alternative if phase order of input or drive is reversed

//Phase lead to make motor spin
const int8_t lead = 2;  //2 for forwards, -2 for backwards

//Status LED
DigitalOut led1(LED1);

//Photointerrupter inputs
DigitalIn I1(I1pin);
DigitalIn I2(I2pin);
DigitalIn I3(I3pin);

//Motor Drive outputs
DigitalOut L1L(L1Lpin);
DigitalOut L1H(L1Hpin);
DigitalOut L2L(L2Lpin);
DigitalOut L2H(L2Hpin);
DigitalOut L3L(L3Lpin);
DigitalOut L3H(L3Hpin);
DigitalOut clk(LED1);

//Timeout function for rotating at set speed
Timeout spinTimer;
float spinWait = 10;
float revsec = 0;

Serial pc(SERIAL_TX, SERIAL_RX);

int8_t orState = 0;    //Rotor offset at motor state 0
int8_t intState = 0;
int8_t intStateOld = 0;

int i=0;



//Set a given drive state
void motorOut(int8_t driveState)
{

    //Lookup the output byte from the drive state.
    int8_t driveOut = driveTable[driveState & 0x07];

    //Turn off first
    if (~driveOut & 0x01) L1L = 0;
    if (~driveOut & 0x02) L1H = 1;
    if (~driveOut & 0x04) L2L = 0;
    if (~driveOut & 0x08) L2H = 1;
    if (~driveOut & 0x10) L3L = 0;
    if (~driveOut & 0x20) L3H = 1;

    //Then turn on
    if (driveOut & 0x01) L1L = 1;
    if (driveOut & 0x02) L1H = 0;
    if (driveOut & 0x04) L2L = 1;
    if (driveOut & 0x08) L2H = 0;
    if (driveOut & 0x10) L3L = 1;
    if (driveOut & 0x20) L3H = 0;
}

//Convert photointerrupter inputs to a rotor state
inline int8_t readRotorState()
{
    return stateMap[I1 + 2*I2 + 4*I3];
}

//Basic synchronisation routine
int8_t motorHome()
{
    //Put the motor in drive state 0 and wait for it to stabilise
    motorOut(0);
    wait(1.0);

    //Get the rotor state
    return readRotorState();
}

void fixedSpeed()
{
    //Read current motor state
    intState = readRotorState();
    //Increment state machine to next state
    motorOut((intState-orState+lead+6)%6);
    //If spinning is required, attach the necessary wait to the
    //timeout interrupt to call this function again and
    //keep the motor spinning at the right speed
    if(revsec) spinTimer.attach(&fixedSpeed, spinWait);
}

//Main function
int main()
{
    pc.printf("Hello\n\r");
    
    //Run the motor synchronisation
    orState = motorHome();
    //orState is subtracted from future rotor state inputs to align rotor and motor states

    pc.printf("Rotor origin: %x\n\r",orState);

    char command[ARRAYSIZE];
    int index=0;
    int units = 0, tens = 0, decimals = 0;
    char ch;
    
    while(1) {
        //Toggle LED so we know something's happening
        clk = !clk;
        
        //If there's a character to read from the serial port
        if (pc.readable()) {
            
            //Clear index counter and control variables
            index = 0;
            revsec = spinWait = 0;
            
            //Read each value from the serial port until Enter key is pressed
            do {
                //Read character
                ch = pc.getc();
                //Print character to serial for visual feedback
                pc.putc(ch);
                //Add character to input array
                command[index++]=ch;  // put it into the value array and increment the index
            //d10 and d13 used for detecting Enter key on Windows/Unix/Mac
            } while(ch != 10 && ch != 13);
            
            //Start new line on terminal for printing data
            pc.putc('\n');
            pc.putc('\r');
            
            //Analyse the input string
            switch (command[0]) {
                //If a V was typed...
                case 'V':
                
                //For each character received, subtract ASCII 0 from ASCII
                //representation to obtain the integer value of the number
                   
                    //If decimal point is in the second character (eg, V.1)
                    if(command[1]=='.') {
                        //Extract decimal rev/s
                        decimals = command[2] - '0';
                    
                    //If decimal point is in the third character (eg, V0.1)
                    } else if(command[2]=='.') {
                        units = command[1] - '0';
                        decimals = command[3] - '0';
                    
                    //If decimal point is in the fourth character (eg, V10.1)
                    } else if(command[3]=='.') {
                        tens = command[1] - '0';
                        units = command[2] - '0';
                        decimals = command[4] - '0';
                    }
                    
                    //Calculate the number of revolutions per second required
                    revsec = float(tens)*10 + float(units) + float(decimals)/10;
                    //Calculate the required wait period
                    spinWait = (1/revsec)/6;
                    
                    //Print values for verification
                    pc.printf("Rev/S: %2.2f, Wait: %2.2f\n\r", revsec, spinWait);
                    
                    //Run the function to start rotating at a fixed speed
                    fixedSpeed();
                    break;
                //If anything unexpected was received
                default:
                    //Set speed variables to zero to stop motor spinning
                    revsec=0;
                    //Print error message
                    pc.printf("Error in received data\n\r");
                    break;
            }
        }
    }

}