Diff: main.cpp

Revision:

3:5467a013d0a0

Parent:

2:9bab1d673af9

Child:

4:e784c25594d7

--- a/main.cpp	Fri Nov 18 15:58:36 2016 +0000
+++ b/main.cpp	Mon Nov 21 13:59:38 2016 +0000
@@ -1,13 +1,13 @@
 #include "mbed.h"
 
-#define VREF                   3300.0f    /* Device power supply in mV */
+#define VREF         3300.0f  /* VRef in mV */
 
 // Parameters for temperature sensor only
-#define AMBIENT_TEMP             25.0f    /* Ambient Temperature in °C */
-#define VSENS_AT_AMBIENT_TEMP   760.0f    /* VSENSE value in mV at ambient temperature */
-#define AVG_SLOPE                25.0f    /* Average slope in mV/°C multiplied by 10 */
+#define AMBIENT_TEMP   25.0f  /* Ambient Temperature in °C */
+#define V25           760.0f  /* VSENSE value in mV at ambient temperature (see product datasheet) */
+#define AVG_SLOPE       2.5f  /* Average slope in mV/°C (see product datasheet) */
 
-//AnalogIn vbat(ADC_VBAT); // To measure VBat
+AnalogIn vbat(ADC_VBAT); // To measure VBat
 AnalogIn tempsensor(ADC_TEMP); // To measure Temperature sensor
 
 DigitalOut led(LED1);
@@ -21,23 +21,15 @@
 
     while(1) {
 
-        /*
-        Note 1: As VBAT voltage could be higher than VDDA, to ensure the correct operation of the ADC, the
-        VBAT pin is internally connected to a bridge divider by 4.
-        Note 2: On some devices the VBAT and temperature sensor are connected to the same ADC internal channel
-        Only one conversion, either temperature sensor or VBAT, must be selected at a time.
-        When both conversion are enabled simultaneously, only the VBAT conversion is
-        performed.
-        */
-        //printf("\nVBat = %.1f mV\n", vbat.read() * VREF * 4);
+        // Measure VBat
+        // Note: As VBAT voltage could be higher than VDDA, to ensure the correct operation of the ADC, the
+        //       VBAT pin is internally connected to a bridge divider by 4.
+        printf("\nVBat = %.1f mV\n", vbat.read() * VREF * 4);
 
+        // Measure temperature sensor
         meas_f = tempsensor.read();
-
-        /* Compute the Junction Temperature value
-        JTemp = ((Vsens - V25)/Avg_Slope) + 25°C
-        The internal temperature sensor supports a temperature range of –40 to 125°C with an accuracy of +/-1.5°C. */
-
-        JTemp_f = (((meas_f * VREF) - VSENS_AT_AMBIENT_TEMP) * 10.0f / AVG_SLOPE) + AMBIENT_TEMP;
+        // Compute the Junction Temperature value: JTemp = ((Vsens - V25)/Avg_Slope) + 25°C
+        JTemp_f = (((meas_f * VREF) - V25) / AVG_SLOPE) + AMBIENT_TEMP;
 
         printf("Internal Temperature = %.1f degree C\n", JTemp_f);