Move ADC_TO_RES macro to header file

stm-firmware/include/reflow-controller/adc-meas.h

@@ -94,6 +94,11 @@
  */
 #define ADC_PT1000_WATCHDOG_SAMPLE_COUNT 25U
 
+/**
+ * @brief Conversion macro: ADC value to resistance
+ */
+#define ADC_TO_RES(adc) ((float)(adc) / 4096.0f * 2500.0f)
+
 /**
  * @brief This function sets up the ADC measurement fo the external PT1000 temperature sensor
  *
@@ -160,6 +165,16 @@ int adc_pt1000_get_current_resistance(float *resistance);
  */
 int adc_pt1000_stream_raw_value_to_memory(volatile float *adc_array, uint32_t length, volatile int *flag_to_set);
 
+/**
+ * @brief Convert an array of raw adc values to resistance values
+ *
+ * In case \p resistance_dest is NULL, the conversion is done inplace in the
+ * \p raw_source array.
+ *
+ * @param resistance_dest Destination. Maybe NULL.
+ * @param raw_source Source array
+ * @param count Number of values to convert
+ */
 void adc_pt1000_convert_raw_value_array_to_resistance(float *resistance_dest, float *raw_source, uint32_t count);
 
 /**