File content as of revision 1:08315c315df0:

#include "mbed.h"

//Analog inputs A0-A5 addressable as such. A6 to A9 do not work.
AnalogIn ANALOG0(A0);
AnalogIn ANALOG1(A1);
AnalogIn ANALOG2(A2);
AnalogIn ANALOG3(A3);
AnalogIn ANALOG4(A4);
AnalogIn ANALOG5(A5);
SPISlave rpi(PB_5, PB_4, PB_3, PA_15); //setup SPI pins to talk to the raspberry pi
//PA_9 - MLB //PA_8 - MLF //PA_10 - MRF //PA_11 - MRB
PwmOut      MRB(PA_11); //back right motor
PwmOut      MRF(PA_10); //front right motor
PwmOut      MLB(PA_9); //back left motor
PwmOut      MLF(PA_8); //front left motor
DigitalOut  RAIN1(PC_6); //PC_9 - Left //PC_6 - Right
DigitalOut  RAIN2(PB_9); // PC_8 - Left //PB_9 - Right
DigitalOut  RSTANDBY(PC_5); //PB_8 - Left //PC_5 - Right
DigitalOut  LAIN1(PC_9);
DigitalOut  LAIN2(PC_8);
DigitalOut  LSTANDBY(PB_8);
//InterruptIn   ENCODER1(PC_7); //PC_12 - MLB //PC_11 - MLF //PB_7 - MRF //PB_6 - MRB
//DigitalIn   ENCODER2(PB_6); //PD_2 - MLB //PC_10 - MLF //PA_13 - MRF //PC_7 - MRB
int m_speed_ref [4] = {0,0,0,0}; //setup array for 4 motor speeds
float m_duty [4] = {0.0, 0.0, 0.0, 0.0}; //setup array for motor pwm duty
int m_distance_ref [4] = {0,0,0,0}; //setup array for 4 motor distances
int max_accel = 0; //for storing the maximum acceleration
int adc_values[6] = {0,0,0,0,0,0}; //setup array for ADC values


int main()
{
    int i = 0; //temp counter variable
    int v = 0; //temp SPI variable
    

    //setup driver pins
    LAIN1 = 1;
    LAIN2 = 0;
    LSTANDBY = 1;
    RAIN1 = 1;
    RAIN2 = 0;
    RSTANDBY = 1;
    // Set PWM
    MRB.period_us(100);
    MRB.write(0.0);
    MRF.period_us(100);
    MRF.write(0.0);
    MLB.period_us(100);
    MLB.write(0.0);
    MLF.period_us(100);
    MLF.write(0.0);

    //setup Spi
 //   rpi.reply(0x00); //set default reply

    while (1) {
        
        //write motor speed
        for (i=0;i<=3;i++){
            m_duty[i] = float(m_speed_ref[i])/100.0;
        }
        MRB.write(m_duty[0]);
        MRF.write(m_duty[1]);
        MLB.write(m_duty[2]);
        MLF.write(m_duty[3]);
        
//read all the ADC values when not doing something else
        adc_values[0] = int(ANALOG0.read()*255);
        adc_values[1] = int(ANALOG1.read()*255);
        adc_values[2] = int(ANALOG2.read()*255);
        adc_values[3] = int(ANALOG3.read()*255);
        adc_values[4] = int(ANALOG4.read()*255);
        adc_values[5] = int(ANALOG5.read()*255);
        
        
        //do SPI communication stuff
        if(rpi.receive()) {
            v = rpi.read();   // Read byte from master
            if(v == char('S')){
                rpi.reply(0x01);
                for (i=0;i<=3;i++){                   
                    m_speed_ref[i] = rpi.read() - 128;
                    rpi.reply(m_speed_ref[i]);
                }
                v = rpi.read(); //last bit setup a blank reply
                rpi.reply(0x00);
            }
            else if(v == char('D')){
                rpi.reply(0x02);
                for (i=0;i<=3;i++){                   
                    m_speed_ref[i] = rpi.read() - 128;
                    rpi.reply(m_speed_ref[i]);
                }
                for (i=0;i<=3;i++){                   
                    m_distance_ref[i] = rpi.read() - 128;
                    rpi.reply(m_distance_ref[i]);
                }
                v = rpi.read(); //last bit setup a blank reply
                rpi.reply(0x00);
            }
            else if(v == char('A')){
                rpi.reply(0x03);                 
                max_accel = rpi.read();
                rpi.reply(max_accel);
                v = rpi.read(); //last bit setup a blank reply
                rpi.reply(0x00);
            }
            else if(v == char('V')){
                rpi.reply(0x04);                 
                v = rpi.read();
                if(v <= 6){ //check the ADC to be addressed exists
                    rpi.reply(adc_values[v]);
                }
                v = rpi.read(); //last bit setup a blank reply
                rpi.reply(0x00);
            }
        }
    }
}