36 lines
1.3 KiB
Arduino
36 lines
1.3 KiB
Arduino
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void readBattery(){
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long millivolts = readVcc();
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//long measured = analogRead(batteryPin);
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//long voltage = millivolts * measured / 1023; // answer is in millivolts
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valBattery = constrain(int(map(millivolts,1500,3400,0,100)),0,100);
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}
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long readVcc() {
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// Read 1.1V reference against AVcc
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// set the reference to Vcc and the measurement to the internal 1.1V reference
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#if defined(__AVR_ATmega32U4__) || defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)
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ADMUX = _BV(REFS0) | _BV(MUX4) | _BV(MUX3) | _BV(MUX2) | _BV(MUX1);
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#elif defined (__AVR_ATtiny24__) || defined(__AVR_ATtiny44__) || defined(__AVR_ATtiny84__)
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ADMUX = _BV(MUX5) | _BV(MUX0);
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#elif defined (__AVR_ATtiny25__) || defined(__AVR_ATtiny45__) || defined(__AVR_ATtiny85__)
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ADMUX = _BV(MUX3) | _BV(MUX2);
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#else
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ADMUX = _BV(REFS0) | _BV(MUX3) | _BV(MUX2) | _BV(MUX1);
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#endif
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delay(2); // Wait for Vref to settle
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ADCSRA |= _BV(ADSC); // Start conversion
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while (bit_is_set(ADCSRA,ADSC)); // measuring
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uint8_t low = ADCL; // must read ADCL first - it then locks ADCH
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uint8_t high = ADCH; // unlocks both
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long result = (high<<8) | low;
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result = 1125300L / result; // Calculate Vcc (in mV); 1125300 = 1.1*1023*1000
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return result; // Vcc in millivolts
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}
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