Read out the stm32 temperature sensor

The value is output using
1. the LCD
2. the UART

The CPU load calculation has been removed/commented out, as it is no
longer used.

src/main.c

@@ -38,7 +38,7 @@ enum OperState {
 
 volatile int wait_frame = 1;
 
-#define ADC_NUM_CHANNELS 3
+#define ADC_NUM_CHANNELS 4
 volatile int16_t adc_values[ADC_NUM_CHANNELS];
 
 static void unlock_rtc_access(void)
@@ -198,11 +198,15 @@ static void init_adc(void)
 	uint8_t channels[ADC_NUM_CHANNELS] = {
 		0, // VInSense
 		1, // VOutSense
-		2  // CurrentSense
+		2, // CurrentSense
+		16 // Temperature sensor
 	};
 
 	adc_power_off(ADC1);
 
+	// enable the temperature sensor
+	adc_enable_temperature_sensor();
+
 	// configure ADC
 	//adc_enable_scan_mode(ADC1);
 	adc_set_single_conversion_mode(ADC1);
@@ -325,11 +329,32 @@ static void init_systick(int freq)
 }
 #endif
 
+/* Temperature sensor calibration value address */
+#define TEMP110_CAL_ADDR ((uint16_t*) ((uint32_t) 0x1FFFF7C2))
+#define TEMP30_CAL_ADDR ((uint16_t*) ((uint32_t) 0x1FFFF7B8))
+#define VDD_CALIB ((uint16_t) (330)) /* calibration voltage = 3,30V - DO NOT CHANGE */
+#define VDD_APPLI ((uint16_t) (330)) /* actual supply voltage */
+
+/* function for temperature conversion */
+static fxp_t calc_temperature(uint16_t adc_val)
+{
+	fxp_t temperature = fxp_from_int(
+			((int32_t)adc_val * VDD_APPLI / VDD_CALIB) -
+			 (int32_t)*TEMP30_CAL_ADDR);
+
+	temperature = fxp_mult(temperature, fxp_from_int(110 - 30));
+	temperature = fxp_div(temperature, fxp_from_int(*TEMP110_CAL_ADDR - *TEMP30_CAL_ADDR));
+
+	return fxp_add(temperature, fxp_from_int(30));
+}
+
 struct PowerState {
 	fxp_t vin, vin_avg;
 	fxp_t vout, vout_avg;
 	fxp_t current, current_avg;
 
+	fxp_t temp, temp_avg; // junction temperature
+
 	fxp_t power_avg;
 };
 
@@ -358,6 +383,10 @@ static void report_status(struct PowerState *power_state,
 
 	fxp_format_int((int32_t)operState, number);
 	debug_send_string(number);
+	debug_send_string(":");
+
+	fxp_format(power_state->temp_avg, number, 1);
+	debug_send_string(number);
 	debug_send_string("\r\n");
 }
 
@@ -505,7 +534,7 @@ static void load_off(void)
 
 int main(void)
 {
-	uint32_t cpuload = 0;
+	//uint32_t cpuload = 0;
 	uint64_t timebase_ms = 0;
 	uint32_t time_in_state = 0;
 	char msg[128];
@@ -577,6 +606,7 @@ int main(void)
 	power_state.vin_avg = 0;
 	power_state.vout_avg = 0;
 	power_state.current_avg = 0;
+	power_state.temp_avg = fxp_from_int(-999);
 
 	mpp_state.mppMaxPWM = CONV_PWM_MAX;
 
@@ -624,6 +654,13 @@ int main(void)
 				lcd_send_string(msg);
 				lcd_send_string("V ");
 
+				lcd_set_cursor_pos(0, 0);
+
+				fxp_format(power_state.temp_avg, number, 1);
+				fxp_right_align(number, msg, 4, ' ');
+				lcd_send_string(msg);
+				lcd_send_string("C");
+
 				lcd_set_cursor_pos(0, 10);
 
 				fxp_format(power_state.power_avg, number, 2);
@@ -633,19 +670,6 @@ int main(void)
 
 				force_display_update_time += 500;
 			}
-
-			if((timebase_ms % 1000) == 10) {
-				cpuload /= 1000;
-
-				lcd_set_cursor_pos(0, 0);
-
-				fxp_format_int((int32_t)cpuload, number);
-				fxp_right_align(number, msg, 3, '0');
-				lcd_send_string("L:");
-				lcd_send_string(msg);
-
-				cpuload = 0;
-			}
 		}
 
 
@@ -674,9 +698,12 @@ int main(void)
 			power_state.current = fxp_add(fxp_mult(fxp_from_int(adc_values[2]), ADC2CURRENT_M), ADC2CURRENT_T);
 		}
 
+		power_state.temp = calc_temperature(adc_values[3]);
+
 		power_state.vin_avg     = fxp_add(fxp_mult(power_state.vin, AVG_FACT),     fxp_mult(power_state.vin_avg, AVG_FACT_INV));
 		power_state.vout_avg    = fxp_add(fxp_mult(power_state.vout, AVG_FACT),    fxp_mult(power_state.vout_avg, AVG_FACT_INV));
 		power_state.current_avg = fxp_add(fxp_mult(power_state.current, AVG_FACT), fxp_mult(power_state.current_avg, AVG_FACT_INV));
+		power_state.temp_avg    = fxp_add(fxp_mult(power_state.temp, AVG_FACT),    fxp_mult(power_state.temp_avg, AVG_FACT_INV));
 
 		power_state.power_avg = fxp_mult(power_state.vout_avg, power_state.current_avg);
 
@@ -972,8 +999,18 @@ int main(void)
 			report_status(&power_state, pwm, operState);
 		}
 
+		/*
+		if((timebase_ms % 1000) == 10) {
+			cpuload /= 1000;
+
+			// use CPU load values here
+
+			cpuload = 0;
+		}
+
 		// cpu load = timer1 value after main loop operations
 		cpuload += timer_get_counter(TIM3);
+		*/
 
 		timebase_ms++;