Merge pull request #49 from rlogiacco/feature/esp32

Configurable ADC resolution

Battery.cpp

@@ -19,7 +19,7 @@
 #include "Battery.h"
 #include <Arduino.h>
 
-Battery::Battery(uint16_t minVoltage, uint16_t maxVoltage, uint8_t sensePin) {
+Battery::Battery(uint16_t minVoltage, uint16_t maxVoltage, uint8_t sensePin, uint8_t adcBits) : adc(0x01 << adcBits) {
 	this->sensePin = sensePin;
 	this->activationPin = 0xFF;
 	this->minVoltage = minVoltage;
@@ -30,15 +30,12 @@ void Battery::begin(uint16_t refVoltage, float dividerRatio, mapFn_t mapFunction
 	this->refVoltage = refVoltage;
 	this->dividerRatio = dividerRatio;
 	pinMode(this->sensePin, INPUT);
-	if (this->activationPin < 0xFF) {
-		pinMode(this->activationPin, OUTPUT);
-	}
 	this->mapFunction = mapFunction ? mapFunction : &linear;
 }
 
 void Battery::onDemand(uint8_t activationPin, uint8_t activationMode) {
-	if (activationPin < 0xFF) {
-		this->activationPin = activationPin;
+	this->activationPin = activationPin;
+	if (activationPin < 0xFF) {	
 		this->activationMode = activationMode;
 		pinMode(this->activationPin, OUTPUT);
 		digitalWrite(activationPin, !activationMode);
@@ -59,16 +56,16 @@ uint8_t Battery::level(uint16_t voltage) {
 	}
 }
 
-uint16_t Battery::voltage() {
+uint16_t Battery::voltage(uint8_t msDelay) {
 	if (activationPin != 0xFF) {
 		digitalWrite(activationPin, activationMode);
 		delayMicroseconds(10); // copes with slow switching activation circuits
 	}
 	analogRead(sensePin);
-	delay(2); // allow the ADC to stabilize
-	uint16_t reading = analogRead(sensePin) * dividerRatio * refVoltage / 1024;
+	delay(msDelay); // allow the ADC to stabilize
+	uint16_t reading = (analogRead(sensePin) * dividerRatio * refVoltage) / adc;
 	if (activationPin != 0xFF) {
 		digitalWrite(activationPin, !activationMode);
 	}
 	return reading;
-}
+}

Battery.h

@@ -32,8 +32,9 @@ class Battery {
 		 * @param minVoltage is the voltage, expressed in millivolts, corresponding to an empty battery
 		 * @param maxVoltage is the voltage, expressed in millivolts, corresponding to a full battery
 		 * @param sensePin is the analog pin used for sensing the battery voltage
+		 * @param adcBits is the number of bits the ADC uses (defaults to 10)
 		 */
-		Battery(uint16_t minVoltage, uint16_t maxVoltage, uint8_t sensePin);
+		Battery(uint16_t minVoltage, uint16_t maxVoltage, uint8_t sensePin, uint8_t adcBits = 10);
 
 		/**
 		 * Initializes the library by optionally setting additional parameters.
@@ -69,8 +70,9 @@ class Battery {
 
 		/**
 		 * Returns the current battery voltage in millivolts.
+		 * @param delay is the amount of milliseconds to wait to allow the ADC input voltage to stabilize (defaults to 2ms)
 		 */
-		uint16_t voltage();
+		uint16_t voltage(uint8_t delay = 2);
 
 	private:
 		uint16_t refVoltage;
@@ -81,6 +83,8 @@ class Battery {
 		uint8_t activationPin;
 		uint8_t activationMode;
 		mapFn_t mapFunction;
+
+		const uint16_t adc;
 };
 
 //