File content as of revision 0:4e20939af8bb:

#include "main.h"

int main()
{
    pc.baud(115200);
    dref.rise(&voltageRise); /// set interrupt to calculate reference frequency
    setupK64Fclocks();
    /// initialise DAC output dac0_out
    while (ref_freq < 1e2) {
        sleep();
    }
    //ref_freq = 5e3;
    /// make sure frequency is read before we go to the program
    /// cancel event-triggered rise interrupt, not to interfere with program
    dref.rise(NULL);
    pc.printf("Ref_Freq is:%.2f kHz\n\r",ref_freq*0.001);
    //constant
    sample_freq = 6*samples16*ref_freq;
    sample_time = 1/sample_freq;

    initDAC();
    delay_freq = ref_freq*amp_points;
    amplitude_delay = 1/delay_freq;
    offset_ticker.attach(&offset_isr,0.001);

    while (offset == 0) {
        if (g_offset_flag == 1) {
            g_offset_flag = 0;
            offset = mavg_filter(filter_points);
        }
        sleep();
    }
    offset_ticker.detach();

    output_ticker.attach(&output_isr,0.00099);
    
    while (true) {
        // gpo = !gpo;
        digitalMix(offset);
        while (g_output_flag == 0) {sleep();} 
        
        if (g_output_flag == 1) {
            g_output_flag = 0;
            //aout = max(samples16);
            aout = 2*max(samples16);
        }
    }
}

double max(int points)
{
    double amp = 0;

    for (int i = 0; i < points; i++) {
        if (amp < R[i])
            amp = R[i];
        //wait(amplitude_delay);
    }
    return amp;
}

double mavg_filter(int filt_points)
{
    double avg = 0, signal = 0;
    double delay = 0.9/(1*ref_freq*filter_points);
    for (int i = 0; i < filter_points; i++) {
        signal = ain.read();
        avg = avg + signal;
         wait((float)(5e-5));
    }
    avg = avg/filter_points;
    return avg;
}

void digitalMix(double remove_offset) {
    /// perform mixing of input and reference signals
    double input = 0;
    for (int i = 0; i < samples16;i++) {
        /// remove the offset before doing the multiplication of signals
        input = ain.read()-remove_offset;
        /// find the X component by multiplying with sine 17 values array
        double refX = input*sin_array16[i];
        /// find the Y component by multiplying with cosine 17 values array
        double refY = input*cos_array16[i];
        //double XY = exp(2*log(refX))+exp(2*log(refY));
        double XY = (refX*refX)+(refY*refY); /// R square
        //double R = exp(0.5*log(XY))/4;
        R[i] = pow(XY,0.5); /// R
        //aout = (1+sin_array16[i])/4;
        //aout = R[i]/2;
        wait(sample_time); /// sample time
    }
}

void voltageRise() {
    if (g_counter == 1) { 
        /// first time function is called is the first rise
        /// start timer
        period_timer.start();
        /// increase counter so next time function is called we calculate freq.
        g_counter++; 
    }
    else if (g_counter == 2) {
        /// second time function is called is the second rise 
        /// stop timer
        period_timer.stop();  
        /// calculate the time taken between the two rises to find period
        ref_period = period_timer.read();
        /// frequency is the inverse of the signal period
        ref_freq = 1/ref_period;
        /// reset timer
        period_timer.reset();
        /// increase counter because we only want to calculate once per cycle
        /// if we want to actively track the ref_freq we should decrease counter
        g_counter++;
    }
}

void setupK64Fclocks() {
    if(1) {
        uint32_t div1=0,div2=0,busClk=0,adcClk=0;
        SystemCoreClockUpdate();
        pc.printf("SystemCoreClock= %u \r\n",SystemCoreClock);
        /// System Core Clock: 120 MHz
        div1=( (SIM->CLKDIV1) & SIM_CLKDIV1_OUTDIV1_MASK)>>SIM_CLKDIV1_OUTDIV1_SHIFT;
        div1=1+div1;
        div2=1+( (SIM->CLKDIV1) &    SIM_CLKDIV1_OUTDIV2_MASK)>>SIM_CLKDIV1_OUTDIV2_SHIFT;
        busClk=SystemCoreClock*div1/div2;
        pc.printf("Divider1== %u div2=%u \r\n",div1,div2);
        pc.printf("MCGOUTCLK= %u,  busClk = %u \r\n",SystemCoreClock*div1,busClk);
        /// MCGOUTCLK 120 MHz, Bus Clock = 120 MHz
        ADC0->SC3 &= ~ADC_SC3_AVGE_MASK;//disable averages
        ADC0->CFG1 &= ~ADC_CFG1_ADLPC_MASK;//high-power mode
        ADC0->CFG1 &= ~0x0063 ; //clears ADICLK and ADIV
        ADC0->CFG1 |= ADC_CFG1_ADIV(2); //divide clock 0=/1, 1=/2, 2=/4, 3=/8
        //ADC0->SC3 |= 0x0007;//enable 32 averages

        if (((ADC0->CFG1)& 0x03) == 0) adcClk = busClk/(0x01<<(((ADC0->CFG1)&0x60)>>5));
        if (((ADC0->SC3)& 0x04) != 0) adcClk = adcClk/(0x01<<(((ADC0->SC3)&0x03)+2));
        pc.printf("adcCLK= %u  \r\n",adcClk);
        /// ADC Clock: 60 MHz
    }   
}

void offset_isr() {
    g_offset_flag = 1;   
}

void output_isr() {
    g_output_flag = 1;   
}

void initDAC() {
        DAC0->C0 = 0;
        DAC0->C1 = 0; //reset DAC state
        DAC0->C0 = DAC_C0_DACEN_MASK | DAC_C0_DACSWTRG_MASK| DAC_C0_DACRFS_MASK;
}