working temperature measurement on ch0

newcode/main.c

@@ -1,6 +1,9 @@
 #include <avr/io.h>
 #include <util/delay.h>
 #include <avr/interrupt.h>
+#include <avr/pgmspace.h>
+#include <stdlib.h>
+#include <stddef.h>
 #include "yaMBSiavr.h"
 
 uint16_t inputStatus[9];
@@ -35,13 +38,44 @@ void init_timer_100us(){
     TCC0.INTCTRLA |= TC_OVFINTLVL_MED_gc;
 }
 
+void adc_init(void){
+    ADCA.CTRLB = 0x00;
+    ADCA.REFCTRL = ADC_REFSEL_VCC_gc;
+    ADCA.PRESCALER = ADC_PRESCALER_DIV512_gc;
+
+    uint8_t CalibrationByteL;
+    uint8_t CalibrationByteH;
+    NVM_CMD = NVM_CMD_READ_CALIB_ROW_gc;
+    CalibrationByteL = pgm_read_byte(offsetof(NVM_PROD_SIGNATURES_t, ADCACAL0));
+    CalibrationByteH = pgm_read_byte(offsetof(NVM_PROD_SIGNATURES_t, ADCACAL1));
+    NVM_CMD = NVM_CMD_NO_OPERATION_gc;
+    ADCA.CALL = CalibrationByteL;
+    ADCA.CALH = CalibrationByteH;
+
+    ADCA.CTRLA = ADC_ENABLE_bm;
+
+    ADCA.CH0.CTRL = ADC_CH_INPUTMODE_SINGLEENDED_gc;
+    ADCA.CH0.MUXCTRL = ADC_CH_MUXPOS_PIN0_gc;
+}
+
+uint16_t adc_read(void){
+    ADCA.CH0.CTRL |= ADC_CH_START_bm;
+    while(!(ADCA.CH0.INTFLAGS & ADC_CH_CHIF_bm));
+    ADCA.CH0.INTFLAGS = ADC_CH_CHIF_bm;
+    return ADCA.CH0.RES;
+}
+
 void modbusGet(void) {
 	if (modbusGetBusState() & (1<<ReceiveCompleted))
     {
         switch(rxbuffer[1]) {
-            case fcReadHoldingRegisters:
-                inputStatus[0]=(~PORTC.IN) & 0xFF;
-                modbusExchangeRegisters(inputStatus, 0, 8);
+            case fcReadHoldingRegisters: ;
+                float tmp[4];
+                tmp[0] = adc_read() - 170;
+                tmp[1] = (tmp[0])/ 3926 * 1.95;
+                tmp[2] = (tmp[1]*993)/(3.3-tmp[1]);
+                tmp[3] = (tmp[2]-100)/0.3927;
+                modbusExchangeRegisters(tmp, 0, 8);
                 break;
             default:
                 modbusSendException(ecIllegalFunction);
@@ -54,6 +88,8 @@ int main(void){
     init_clk();
     PORTD.DIRSET = 1 << 5;
 
+    adc_init();
+
     PORTCFG.MPCMASK = 0xFF;
     PORTC.PIN1CTRL = PORT_OPC_PULLUP_gc;