thermocouple/firmware/slavechip/main.c

#include "main.h"
#include "spi.h"
#include "muxer.h"
#include "i2c_simple.h"
#include "mcp_adc.h"
#include "debug.h"
#include "filter.h"
#include "offset.h"

#include <math.h>
#include <util/delay.h>
#include <stdio.h>

uint16_t timertmp;
uint16_t temperatures[4];

/* pinout
 * - i2c:
 *		C5
 *		C4
 * - multiplexer:
 *		C3: inhibit
 *		C0-C2: muxer select
 *
 * amp 0 is on muxer channel 2
 */


/* initializes the hardware */
void hardinit() {
  // enable softtimer isr
  TCCR1A = _BV(WGM10);
  TCCR1B = _BV(WGM12) | _BV(CS11); // clk/8 prescaler, 4kHz PWM-freq.
  TIMSK1 |= _BV(TOIE1);

  spi_init();

  muxer_init();
  
  i2c_init();

  sei();
}

void softinit() {
	mcpadc_init(ADC_GAIN_2|ADC_CONV_CONT|ADC_BITS_16);
    dbg_init();
    stdout = &mystdout;
    printf("======= starting logging\n");
}


int __attribute__((noreturn)) main(void) {
	hardinit();
	softinit();

	/*muxer_set(1);
    offset_measure_start(1);
    for(;;);*/

	int16_t data;
	for(;;){
        printf("====== loop iteration\n");
        


		// measure temps 5*2 times
		for(uint8_t i=0; i<5; i++) {
            printf("====== now measuring temps\n");
			for(uint8_t active_sensor=0; active_sensor<2; active_sensor++) { // only measuring two probes atm
                printf("=== active sensor: %i\n",active_sensor);
				muxer_set(active_sensor);
                _delay_ms(1000);
				while(!mcpadc_has_new_data()) _delay_ms(10);
				mcpadc_get_data(); // first data after switch to trash
				while(!mcpadc_has_new_data()) _delay_ms(10);
				
				data = mcpadc_get_data();
                process_thermocouple_value(data,active_sensor);
			}
		}

		// measure 2 offsets
		for(uint8_t active_sensor=0; active_sensor<2; active_sensor++)
            if(offset_measure[active_sensor]) {
                printf("=== measuring offset, sensor: %i\n",active_sensor);
                muxer_set(active_sensor);
                while(!mcpadc_has_new_data()) _delay_ms(10);
                mcpadc_get_data(); // first data after switch to trash
                while(!mcpadc_has_new_data()) _delay_ms(10);
                
                offset_val[active_sensor] = mcpadc_get_data();
                
                while(offset_measure[active_sensor]) {
                    offset_val[active_sensor] += mcpadc_get_data();
                }
            }
        
        // measure ambient
        printf("====== now measuring ambient\n");
        muxer_set(5);
        while(!mcpadc_has_new_data()) _delay_ms(10);
        mcpadc_get_data(); // first data after switch to trash
        while(!mcpadc_has_new_data()) _delay_ms(10);
        data = mcpadc_get_data();
        process_ambient_value(data);
	}
	
}


ISR(TIMER1_OVF_vect,ISR_NOBLOCK){
    timertmp=timer1_acc;
    timertmp++;

    /* the ATOMIC is acutally only needed if timer1_acc is never read from an ISR, which
     * is probably the case.
     * ATOMIC_FORCEON: the ISR_NOBLOCK sets sei() a few cycles before.
     */
    ATOMIC_BLOCK(ATOMIC_FORCEON){ 
        timer1_acc=timertmp;
    }

}