File content as of revision 0:011f69c1276c:

#include "mbed.h"

/* 
##############################
Constants
##############################
*/ 
const float ADC_INPUT_MAX_VALUE = 5;
const float ADC_OUTPUT_MAX_VALUE = 5;

const float PEDAL_HI_MIN_VALUE = 0.48;
const float PEDAL_HI_MAX_VALUE = 2.96;
const float PEDAL_LO_MIN_VALUE = 0.25;
const float PEDAL_LO_MAX_VALUE = 1.48;

/* 
##############################
Static variables and functions
##############################
*/ 
static float __reference_speed = 0;
static float __measured_speed = 0;

static void setReferenceSpeed(const float speed) {
    // TODO insert mutex here
    __reference_speed = speed;
}

static void setMeasuredSpeed(const float speed) {
    // TODO insert mutex here
    __measured_speed = speed;
}

static float getReferenceSpeed() {
    // TODO insert mutex here
    return __reference_speed;
}
static float getMeasuredSpeed() {
    // TODO insert mutex here
    return __measured_speed;
}

/* 
##############################
uC I/O
##############################
*/ 
AnalogIn pedal_in_hi(A0);
AnalogIn pedal_in_lo(A1);
AnalogOut pedal_out_hi(A2);
AnalogOut pedal_out_lo(A3);
DigitalOut led(LED1);

/* 
##############################
Utility functions
##############################
*/ 

// Returns 'value' bounded between 'lowerBound' and 'upperBound'
float boundValue(float value, const float lowerBound, const float upperBound) {
    if(value < lowerBound) {
        value = lowerBound;
    }
    else if(value > upperBound) {
        value = upperBound;
    }
    return value;
}

// Returns "value/reference" as a percentage in decimal form (0.5 for 50%)
float toDecimalPercent(const float value, const float reference) {
    return value/reference;
}

// Returns voltage read on analog input port chosen for pedal input 1
float readAdcPedalHi() {
    const float decPcValue = pedal_in_hi.read();
    const float voltage = decPcValue * ADC_INPUT_MAX_VALUE;
    return voltage;
}

// Returns voltage read on analog input port chosen for pedal input 2
float readAdcPedalLo() {
    const float decPcValue = pedal_in_lo.read();
    const float voltage = decPcValue * ADC_INPUT_MAX_VALUE;
    return voltage;
}


// Accepts a value in volts, converts to % and sets ADC for pedal output 1
void writeAdcPedalHi(const float voltage) {
    const float boundedValue = boundValue(voltage, PEDAL_HI_MIN_VALUE, PEDAL_HI_MAX_VALUE);
    const float decPcValue = toDecimalPercent(boundedValue, ADC_OUTPUT_MAX_VALUE);
    pedal_out_hi.write(decPcValue);
}

// Accepts a value in volts, converts to % and sets ADC for pedal output 2
void writeAdcPedalLo(const float voltage) {
    const float boundedValue = boundValue(voltage, PEDAL_LO_MIN_VALUE, PEDAL_LO_MAX_VALUE);
    const float decPcValue = toDecimalPercent(boundedValue, ADC_OUTPUT_MAX_VALUE);
    pedal_out_lo.write(decPcValue);
}



// main transfer function
void controlFunctionCallback() {
//    const float Ki = 1.0;
//    const float Kp = 1.0;
//    const float Kc = 1.0;
//    
//    const float Vref = getReferenceSpeed();
//    const float Vmes = getMeasuredSpeed();
//    const float err = Vref - Vmes;
//    const float errKi = err * Ki;
//    const float err2 = errKi - Vmes;
//    const float Ud = err2 * Kp * Kc;
    const float udHi = readAdcPedalHi();
    const float udLo = readAdcPedalLo();
    writeAdcPedalHi(udHi);
    writeAdcPedalLo(udLo);
}



int main() {
    printf("\nAnalogIn example\n");
    setReferenceSpeed(0);
    setMeasuredSpeed(0);
    printf("%f", getReferenceSpeed());
    printf("%f", getMeasuredSpeed());
    
    while(1) {
        controlFunctionCallback();
        led.write(!led.read());
        wait(0.2); // 200 ms
    }
}