hacked a lot of postprocessing

firmware/shared/spi_proto.c

@@ -95,9 +95,7 @@ uint16_t spi_proto_slaveaction(uint8_t opcode, uint8_t addr, uint16_t data) {
 			break;
 		case 7:
 #ifndef SPI_MASTER
-			if(addr < 4) {
-				retval = temperatures[addr];
-			} else return 0;
+            retval = get_temperature(addr);
 #endif
 			break;
 		default:

firmware/slavechip/filter.c

@@ -2,13 +2,52 @@
 #include "filter.h"
 #include <math.h>
 
-#define CHANNELCOUNT 8
+Sensordata sensordata[4];
+float ambient_temp=25.;
+
 
 float avg_cumul[CHANNELCOUNT];
 float avg_lastval[CHANNELCOUNT];
 uint8_t avg_count[CHANNELCOUNT];
 float avg_noise[CHANNELCOUNT];
 
+
+void process_thermocouple_value(int16_t raw_data, uint8_t channel){
+    // This function does everything that needs to be done to raw adc values
+    float a = raw_data;
+    a -= sensordata[channel].offset; 
+    a = a*0.000625;  // adc count to voltage (mV)
+    a = filter_voltage_to_temp(a); // voltage to temp
+    // TODO: first ambient->voltage, add that to a, then voltage->temp
+    a += ambient_temp; // compensate ambient temperature
+    // TODO: lowpass
+    
+    uint16_t result = filter_float_to_fixpoint(a);
+    sensordata[channel].temperature = result;
+}
+
+void process_offset_value(int16_t raw_data, uint8_t channel){
+    sensordata[channel].offset = raw_data;
+}
+
+void process_ambient_value(int16_t raw_data){
+    // 9.625mV after amp  per °C
+    float a = raw_data;
+    a = a * 0.03125; //adc to mV after amp
+    a = a / 9.625;
+    ambient_temp = a;
+    dbgLog("ambient: %3.3f°C (lastval %i)\n",a, raw_data);
+}
+
+
+uint16_t get_temperature(uint8_t channel){
+    if(channel>=4){
+        return 0;
+    }
+    return sensordata[channel].temperature;
+}
+
+
 void filter_average_input(uint8_t channel, float value) {
 	avg_cumul[channel] += value;
 	float noisetmp = avg_lastval[channel] - value;	
@@ -44,8 +83,8 @@ float filter_average_noise(uint8_t channel){
 	return noise;
 }
 
-uint16_t filter_float_to_decimal8(float f){
-	return( (uint16_t)(f / 256.) );
+uint16_t filter_float_to_fixpoint(float f){
+	return( (uint16_t)(f * 256.) );
 }
 
 //uint16_t calc_temp(int16_t val, uint8_t channel) {

firmware/slavechip/filter.h

@@ -1,6 +1,22 @@
 
 #include <stdint.h>
 
+#define CHANNELCOUNT 8
+typedef struct {
+    int16_t offset; // in adc-counts TODO:float?
+    // TODO fir-data
+    uint16_t temperature;
+} Sensordata;
+
+extern Sensordata sensordata[4];
+extern float ambient_temp;
+
+void process_thermocouple_value(int16_t raw_data, uint8_t channel);
+void process_offset_value(int16_t raw_data, uint8_t channel);
+void process_ambient_value(int16_t raw_data);
+    
+uint16_t get_temperature(uint8_t channel);
+
 void filter_average_input(uint8_t channel, float value);
 
 uint8_t filter_average_done(uint8_t channel, uint8_t samples);
@@ -11,7 +27,7 @@ float filter_average_result(uint8_t channel);
 
 float filter_average_noise(uint8_t channel);
 
-uint16_t filter_float_to_decimal8(float f);
+uint16_t filter_float_to_fixpoint(float f);
 
 float filter_voltage_to_temp(float mV);
 

firmware/slavechip/main.c

@@ -54,19 +54,19 @@ int __attribute__((noreturn)) main(void) {
 
 	muxer_set(1);
 
-	uint8_t active_sensor = 0;
 	int16_t data;
 	for(;;){
 
 		// measure temps 5*2 times
 		for(int i=0; i<5; i++) {
-			for(int active_sensor=0; active_sensor<2; active_sensor++) { // only measuring two probes atm
+			for(uint8_t active_sensor=0; active_sensor<2; active_sensor++) { // only measuring two probes atm
 				muxer_set(active_sensor);
 				while(!mcpadc_has_new_data()) _delay_ms(1);
 				mcpadc_get_data(); // first data after switch to trash
 				while(!mcpadc_has_new_data()) _delay_ms(1);
 				
 				data = mcpadc_get_data();
+                process_thermocouple_value(data,active_sensor);
 				float f = filter_voltage_to_temp(((float)data) * 0.000625 );
 				filter_average_input(active_sensor, f);
 				if(filter_average_done(active_sensor,16)){
@@ -77,7 +77,7 @@ int __attribute__((noreturn)) main(void) {
 		}
 
 		// measure 2 offsets
-		for(int active_sensor=0; active_sensor<2; active_sensor++) { // only measuring two offsets atm
+		for(uint8_t active_sensor=0; active_sensor<2; active_sensor++) { // only measuring two offsets atm
 			muxer_set(active_sensor);
 			offset_measure_start(active_sensor);
 			while(!mcpadc_has_new_data()) _delay_ms(1);
@@ -85,12 +85,22 @@ int __attribute__((noreturn)) main(void) {
 			while(!mcpadc_has_new_data()) _delay_ms(1);
 
 			data = mcpadc_get_data();
+            process_ambient_value(data);
 			// TODO: what to do with the offset?
 			
 			offset_measure_stop();
 		}
+        
+        // measure ambient
+        muxer_set(5);
+        while(!mcpadc_has_new_data()) _delay_ms(1);
+        mcpadc_get_data(); // first data after switch to trash
+        while(!mcpadc_has_new_data()) _delay_ms(1);
+        data = mcpadc_get_data();
+        process_ambient_value(data);
 
-		SOFTTIMER(1,8000) { // maybe measure coldjunction comp
+
+/*		SOFTTIMER(1,8000) { // maybe measure coldjunction comp
 			muxer_set(23); // TODO: channel for ntc?!
 			
 			// first measure ntc offset?! maybe?
@@ -108,7 +118,7 @@ int __attribute__((noreturn)) main(void) {
 			while(!mcpadc_has_new_data()) _delay_ms(1);
 
 			data = mcpadc_get_data();			
-		}
+		}*/
 		
 
     

firmware/slavechip/muxer.c

@@ -1,6 +1,13 @@
 #include "muxer.h"
 #include <avr/io.h>
 
+
+/*****************
+ * themor-sensors are channels 0-3
+ *
+ * pt1000 is on channel 5
+ */
+
 void muxer_init(){
 	DDRC |= (_BV(0)|_BV(1)|_BV(2)|_BV(3)); // conf as outputs
 	PORTC |= _BV(3); // inhibit