File content as of revision 0:722b391fe228:

#include "mbed.h"
// APIs
Serial pc(USBTX, USBRX); // tx, rx for serial USB interface to pc
SPI spi_max1270(p5, p6, p7);
SPI spi(p5, p6, p7);
DigitalOut max1270_cs(p8);  //MAX1270 ADC CS
//DigitalOut max522_cs(p11);  //MAX522 DAC CS
DigitalOut mot1_ph1(p21);
DigitalOut mot1_ph2(p22);
PwmOut mot_en1(p23);

/*DigitalOut mot2_ph1(p24);
DigitalOut mot2_ph2(p25);
PwmOut mot_en2(p26);*/

int read_max1270(int chan, int range, int bipol){
    int cword=0x80;     //set the start bit
    
    spi_max1270.frequency(10000000);
    spi_max1270.format(8, 0);   // 8 data bits, CPOL0, and CPHA0 (datasheet Digital Interface)
        
    cword |= (chan << 4);   //shift channel
    cword |= (range << 3);
    cword |= (bipol << 2);
            
    max1270_cs = 0;
           
    spi_max1270.write(cword);
    wait_us(15);    //15us
    spi_max1270.format(12, 3);
    
    int result = spi_max1270.write(0);
    
    max1270_cs = 1;
    spi_max1270.format(8, 0);
    return result;
}

float read_max1270_volts(int chan, int range, int bipol){
    float rangevolts=0.0;
    float volts=0.0;
    int adc_res;

    //read the ADC converter
    adc_res = read_max1270(chan, range, bipol) & 0xFFF;
        
   //Determine the voltage range
   if(range)  //RNG bit 
     rangevolts=10.0;
   else
     rangevolts=5.0;
             
   //bi-polar input range
   if(bipol){ //BIP is set, input is +/-
     if(adc_res < 0x800){ //if result was positive
      volts = ((float)adc_res/0x7FF) * rangevolts;      
     }       
     else{  //result was negative
      volts = -(-((float)adc_res/0x7FF) * rangevolts) - (rangevolts * 2.0); 
     }
   }
   else{  //input is positive polarity only
      volts = ((float)adc_res/0xFFF) * rangevolts;   
   }
   
   return volts;     
}

//Motor control routine for PWM on 5 pin motor driver header
// drv_num is 1 or 2 (defaults to 1, anything but 2)
// dc is signed duty cycle (+/-1.0)

/*void mot_control(int drv_num, float dc){        
    if(dc>1.0)
        dc=1.0;
    if(dc<-1.0)
        dc=-1.0;
    
    if(drv_num != 2){           
        if(dc > 0.0){
            mot1_ph2 = 0;
            mot1_ph1 = 1;
            mot_en1 = dc;
        }
        else if(dc < -0.0){
            mot1_ph1 = 0;
            mot1_ph2 = 1;
            mot_en1 = abs(dc);
        }
        else{
            mot1_ph1 = 0;
            mot1_ph2 = 0;
            mot_en1 = 0.0;
        }
    }                
    else{
        if(dc > 0.0){
            mot2_ph2 = 0;
            mot2_ph1 = 1;
            mot_en2 = dc;
        }
        else if(dc < -0.0){
            mot2_ph1 = 0;
            mot2_ph2 = 1;
            mot_en2 = abs(dc);
        }
        else{
            mot2_ph1 = 0;
            mot2_ph2 = 0;
            mot_en2 = 0.0;
        }
    }                   
}*/

//------- MAX522 routines ---------------------------------
/*void write_max522(int chan, float volts){
    int cmd=0x20;   //set UB3
    int data_word = (int)((volts/5.0) * 256.0);
    if(chan != 2)
        cmd |= 0x01;    //set DAC A out
    else
        cmd |= 0x02;    //set DACB out        
    
 //   pc.printf("cmd=0x%4X  data_word=0x%4X \r\n", cmd, data_word);
    
    spi.format(8, 0);
    spi.frequency(2000000);
    max522_cs = 0;
    spi.write(cmd & 0xFF);
    spi.write(data_word & 0xFF);
    max522_cs = 1;    
    spi.frequency(10000000);
}*/

float Tank1,Tank2,dt,h1,h2;
float Ts = 0.5; // 1/Ts Hz
float c1 = 15.0/(2.77+1.24); // cm/V
float c2 = 11.5/(3.58-0.79); // cm/V
float v10 = -0.52; // V
float v20 = -3.35; // V
Timer t;

float cntr;
float dc;
int main ()
{
    pc.baud(921600);
    mot_en1.period_us(50);    
    max1270_cs = 1;
    //Ts = 0.1; 
    //dc = 0.2;
    cntr = 0.0;
    while(cntr*Ts <= 120) {
        t.start(); // start measuring comp time
        // Read pressure sensors
                
        Tank1 = read_max1270_volts(0, 1, 1);
        h1 = c1*(Tank1 - v10);
        Tank2 = read_max1270_volts(1, 1, 1);
        h2 = c2*(Tank2 - v20);
        // drive motor
        //if (cntr*Ts <= 0.05) {
        //    dc = 0.0;
        //} else if (cntr*Ts <= 0.2) {
        //    dc = 0.3;
        //} else {
        //    dc = 0.7;
        //}
        
        if (cntr*Ts <= 5) {
            dc = 0.0;
        } else if (cntr*Ts <= 110) {
            dc = -0.75;
        } else {
            dc = 0.0;
        }
        
        //dc = 0.75;
        //mot_control(1,-dc);
        
        if(dc > 0.0){
            mot1_ph2 = 0;
            mot1_ph1 = 1;
            mot_en1 = dc;
        }
        else if(dc < -0.0){
            mot1_ph1 = 0;
            mot1_ph2 = 1;
            mot_en1 = abs(dc);}
        
       
        t.stop(); // end measuring comp time
        //printf("%f\n\r",t.read());
        dt = Ts-t.read();
        //printf("%f\n\r",dt);
        pc.printf("%5.2f %5.2f %5.2f %5.2f %5.2f %5.2f \n\r",cntr*Ts,Tank1,Tank2,h1,h2,dc);
        //printf("%5.2f \n\r",angleNew);
        t.reset();
        cntr=cntr+1;
        wait(dt); // wait to ensure sampling period set by Ts    
    }//while
    mot1_ph2 = 0;
    mot_en1 = 0.0;
}//main