File content as of revision 1:ab3dacbfcde6:

#include "mbed.h"

#define M_PI 3.14159265358979323846

#define N_SAMPLES 500

//mbed class def
Serial pc(USBTX, USBRX); // tx, rx
SPI spi(p5, p6, p7); // mosi, miso, sclk
DigitalOut cs(p8);

PwmOut motorOn(p26);

Timer t;

//variable instaniation
unsigned short calData[6];

char buffer16[3];
short int serbuffer[2];

char tempBuffer[4];
unsigned int temp = 0;
char pressBuffer[4];
unsigned int press = 0;

unsigned int pData[N_SAMPLES];
float spData[N_SAMPLES];
unsigned int tData[N_SAMPLES];

const char cb1 = 0xA2;
const char cb2 = 0xA4;
const char cb3 = 0xA6;
const char cb4 = 0xA8;
const char cb5 = 0xAA;
const char cb6 = 0xAC;

const char * commarr[6] = {&cb1, &cb2, &cb3, &cb4, &cb5, &cb6};

const char D1conv256 = 0x40;
const char D1conv512 = 0x42;
const char D2conv4096 = 0x58;
const char D2conv512 = 0x52;
const char readADC = 0x00;

float duty = 1;

int round(float number)
{
    return (number >= 0) ? (int)(number + 0.5) : (int)(number - 0.5);
}

//calculate temperature
int calcT(unsigned int Tval, unsigned short consts[6])
{
    int dT = Tval - consts[4]*(2<<7);

    int T = 2000 + dT*consts[5]/(2<<22);
    printf("Temp: %d C\n", T);
    return T;
}

//calculate 1st order temperature compensated pressure
int calcP(unsigned int Tval, unsigned int Pval, unsigned short consts[6])
{
    int dT = Tval - consts[4]*(2<<7);

    long long int off = (long long)consts[1]*(2<<16) + ((long long)consts[3] *(long long)dT)/(2<<5);

    long long int sens = (long long)consts[0]*(2<<15) + ((long long)consts[2] *(long long)dT)/(2<<6);

    int P = (Pval *(sens/(2<<20)) - off)/(2<<14);
    //printf("Pressure %d Pa\n\r", P);
    return P;
}

int main()
{
    printf("Turrentine\n");
        
    pc.baud(115200);
    motorOn = 0;
    motorOn.period_ms(10);

    // Chip must be deselected
    cs = 1;

    // Setup the spi for 8 bit data, high steady state clock,
    // second edge capture, with a 1MHz clock rate
    spi.format(8,3);
    spi.frequency(500000);
    spi.set_default_write_value(0x00);

    // Select the device by seting chip select low
    cs = 0;

    // Send 0x1E Command to reset the chip
    spi.write(0x1E);
    cs = 1;
    wait_ms(100);
    cs = 1;
    
    printf("Read cal data\n");

    //read cal data values from device into program
    for (char i=0; i<6; i++) {
        //spi read sequence
        cs= 0;
        spi.write(commarr[i], 1, buffer16, 3);
        //time for SPI to write into data buffers
        wait_ms(10);
        cs=1;
        //Put data into 16bit unsigned int in calData array
        calData[i] = buffer16[1]<<8 | buffer16[2];
    }
    
    printf("Start loop\n");

    //display calibration values to check against datasheet

    //program loop
    while(1) {
        //read temerature value
        cs = 0;
        spi.write(&D2conv4096, 1, buffer16, 1);
        wait_ms(10);
        cs = 1;
        cs = 0;

        spi.write(&readADC, 1, tempBuffer, 4);
        cs = 1;

        //read pressure value
        /*cs = 0;
        spi.write(&D1conv512, 1, buffer16, 1);
        wait_ms(2);
        cs = 1; cs = 0;

        spi.write(&readADC, 1, pressBuffer, 4);
        cs = 1;*/

        //write values from buffers to program variables
        temp = tempBuffer[1]<<16 | tempBuffer[2]<<8 | tempBuffer[3];
        //press = pressBuffer[1]<<16 | pressBuffer[2]<<8 | pressBuffer[3];

        printf("Pump On\n");

        //turn pump on
        motorOn.write(duty);

        //dummy samples to wait for sensor response to stabilise
        int a =0;
        while(a < 10000) {
            cs = 0;
            spi.write(&D1conv256, 1, buffer16, 1);
            wait_us(500);
            cs = 1;
            cs = 0;
            spi.write(&readADC, 1, pressBuffer, 4);
            cs = 1;
            a++;
        }
        
        printf("Start Measurement\n");

        //double cumsum = 0;

        t.reset();
        t.start();
        //loop values
        for (int x = 0; x < N_SAMPLES; x++) {
            cs = 0;
            spi.write(&D1conv256, 1, buffer16, 1);
            wait_us(500);
            cs = 1;

            cs = 0;
            if (x > 0) {
                pData[x-1] = pressBuffer[1]<<16 | pressBuffer[2]<<8 | pressBuffer[3];
                //cumsum = cumsum + pData[x-1];
            }
            spi.write(&readADC, 1, pressBuffer, 4);
            tData[x] = t.read_us();
            cs = 1;
        }

        pData[N_SAMPLES - 1] = pressBuffer[1]<<16 | pressBuffer[2]<<8 | pressBuffer[3];

        //stop motor and timer
        t.stop();
        motorOn.write(0);
        
        printf("Stop Measurement\n");

        //calc temperature
        calcT(temp, calData);
        long long sum = 0;

        //float avg = calcP(temp, cumsum/(nsample-1), calData);

        //printf("avg %f\n\r", avg);

        //output date to PC
        printf("C1: %hu\nC2: %hu\nC3: %hu\nC4: %hu\nC5: %hu\nC6: %hu\n", calData[0], calData[1], calData[2], calData[3], calData[4], calData[5]);

        for(int i = 0; i < N_SAMPLES; i++) {
            printf("%04d: %d\n", i, pData[i]);
        }

        /*
        //for crossing detection
        bool cflag1 = (avg > pData[0]);
        bool cflag2 = (avg > pData[1]);
        int numcross = 0;
        int lastcrosspoint = 0;
        unsigned int crosstart;
        unsigned int crossend;
        float freq = 0;
        
        //smooth data array 20 sample size
        for (int y=0; y< nsample-1; y++) {
        if (9< y && y <nsample-10) {
        sum = 0;
        for (int z=0; z<20; z++) {
        sum = sum + pData[y-10+z];
        }

        spData[y] = (float) calcP(temp, sum/20, calData);

        //detect avg crossings for frequency calc
        if (y>10) {
        cflag2 = (avg > spData[y]);
        cflag1 = (avg > spData[y-1]);

        if (cflag1 != cflag2) {
        if(lastcrosspoint<=(y-10)) {
        numcross++;
        lastcrosspoint = y;

        if (numcross == 1) {
        crosstart = tData[y];
        }

        crossend = tData[y];
        }
        }
        }
        //calc pressure & display list
        //printf("%d\t%d\t%d\n\r", tData[y], calcP(temp, spData[y], calData), calcP(temp, pData[y], calData));
        printf("%d\t%f\n\r", tData[y],spData[y]);
        } else if (10> y || y >nsample-10) {
        spData[y] = (float) calcP(temp, pData[y], calData);
        }


        }

        printf("numcross = %d\n\r", numcross);
                           printf("crosstart = %d\n\r", crosstart);
                                   printf("crossend = %d\n\r", crossend);

                                           freq = (1e6 *numcross)/(2*(crossend - crosstart));
                                           printf("frequency = %f\n\r", freq);

                                                   for (int z=0; z< nsample-1; z++) {

                                                   spData[z] = spData[z] -avg;
                                               }

                                                   printf("Repeat Blockage Test?\n\rPress Enter to continue\n\r");

                                                   while(1) {
                                                   if (pc.getc() != 0) {
                                                   break;
                                               }
                                               }
                                                   */
    }
}