Added MeasureVoltageAndResistance measurement

Author: ArminJo

SBMInfo/ADCUtils.cpp

@@ -334,24 +334,37 @@ float getVCCVoltage(void) {
 }
 
 /*
- * Read value of 1.1 volt internal channel using VCC as reference.
+ * Or getVCCVoltageMillivolt() * 1023 / 1100
+ */
+uint16_t getVCCVoltageReadingFor1_1VoltReference(void) {
+    checkAndWaitForReferenceAndChannelToSwitch(ADC_1_1_VOLT_CHANNEL_MUX, DEFAULT);
+    uint16_t tVCC = readADCChannelWithReferenceOversample(ADC_1_1_VOLT_CHANNEL_MUX, DEFAULT, 2);
+    /*
+     * Do not switch back ADMUX to enable checkAndWaitForReferenceAndChannelToSwitch() to work correctly for the next measurement
+     */
+    return ((1023L * 1023L) / tVCC);
+}
+
+/*
+ * Read value of 1.1 volt internal channel using VCC (DEFAULT) as reference.
  * Handles reference and channel switching by introducing the appropriate delays.
  * !!! Resolution is only 20 millivolt !!!
  */
 uint16_t getVCCVoltageMillivolt(void) {
-    uint8_t tOldADMUX = checkAndWaitForReferenceAndChannelToSwitch(ADC_1_1_VOLT_CHANNEL_MUX, DEFAULT);
+    checkAndWaitForReferenceAndChannelToSwitch(ADC_1_1_VOLT_CHANNEL_MUX, DEFAULT);
     uint16_t tVCC = readADCChannelWithReferenceOversample(ADC_1_1_VOLT_CHANNEL_MUX, DEFAULT, 2);
-    ADMUX = tOldADMUX;
     /*
-     * Do not wait for reference to settle here, since it may not be necessary
+     * Do not switch back ADMUX to enable checkAndWaitForReferenceAndChannelToSwitch() to work correctly for the next measurement
      */
     return ((1023L * 1100) / tVCC);
 }
 
-void printVCCVoltageMillivolt(Print *aSerial) {
+uint16_t printVCCVoltageMillivolt(Print *aSerial) {
     aSerial->print(F("VCC="));
-    aSerial->print(getVCCVoltageMillivolt());
+    uint16_t tVCCVoltageMillivolt = getVCCVoltageMillivolt();
+    aSerial->print(tVCCVoltageMillivolt);
     aSerial->println(" mV");
+    return tVCCVoltageMillivolt;
 }
 
 /*
@@ -362,9 +375,8 @@ float getTemperature(void) {
     return 0.0;
 #else
     // use internal 1.1 volt as reference
-    uint8_t tOldADMUX = checkAndWaitForReferenceAndChannelToSwitch(ADC_TEMPERATURE_CHANNEL_MUX, INTERNAL);
+    checkAndWaitForReferenceAndChannelToSwitch(ADC_TEMPERATURE_CHANNEL_MUX, INTERNAL);
     float tTemp = (readADCChannelWithReferenceOversample(ADC_TEMPERATURE_CHANNEL_MUX, INTERNAL, 2) - 317);
-    ADMUX = tOldADMUX;
     return (tTemp / 1.22);
 #endif
 }

SBMInfo/ADCUtils.h

@@ -126,7 +126,8 @@ uint16_t getVCCVoltageMillivoltSimple(void);
 float getTemperatureSimple(void);
 float getVCCVoltage(void);
 uint16_t getVCCVoltageMillivolt(void);
-void printVCCVoltageMillivolt(Print* aSerial);
+uint16_t printVCCVoltageMillivolt(Print* aSerial);
+void printVCCVoltageMillivolt(Print* aSerial, uint16_t aVCCVoltageMillivolt);
 float getTemperature(void);
 
 #endif // defined(ADATE)