batt display, low batt shutdown, timeout shutdown

lib/BatterySense/src/Battery.cpp

@@ -0,0 +1,74 @@
+/*
+ Battery.cpp - Battery library
+ Copyright (c) 2014 Roberto Lo Giacco.
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU Lesser General Public License as 
+ published by the Free Software Foundation, either version 3 of the 
+ License, or (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "Battery.h"
+#include <Arduino.h>
+
+Battery::Battery(uint16_t minVoltage, uint16_t maxVoltage, uint8_t sensePin) {
+	this->sensePin = sensePin;
+	this->activationPin = 0xFF;
+	this->minVoltage = minVoltage;
+	this->maxVoltage = maxVoltage;
+}
+
+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->activationMode = activationMode;
+		pinMode(this->activationPin, OUTPUT);
+		digitalWrite(activationPin, !activationMode);
+	}
+}
+
+uint8_t Battery::level() {
+	return this->level(this->voltage());
+}
+
+uint8_t Battery::level(uint16_t voltage) {
+	if (voltage <= minVoltage) {
+		return 0;
+	} else if (voltage >= maxVoltage) {
+		return 100;
+	} else {
+		return (*mapFunction)(voltage, minVoltage, maxVoltage);
+	}
+}
+
+uint16_t Battery::voltage() {
+	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;
+	if (activationPin != 0xFF) {
+		digitalWrite(activationPin, !activationMode);
+	}
+	return reading;
+}