After several tries, i was successful with reading stable battery voltage using internal voltage reference of 1.1v, now the issue i face is that i cannot read stable sensor voltage, could you please let me know how can i read my sensor voltage? or do i need additional voltage divider (my sensor goes directly to A0 and GND pin).
void setup(){ Serial.begin(9600); } void loop() { //REFS1 AND REFS0 to 1 1 -> internal 1.1V refference ADMUX |= B11000000; //We read A1 (MUX0) for battery voltage ADMUX |= B00000001; //We read A0 for sensor voltage ADMUX |= B00000000; // for my sensor // Start AD conversion ADCSRA |= B11000000; // Detect end-of-conversion while (bit_is_set(ADCSRA,ADSC)); float val = ADCL | (ADCH << 8); val = val * 5.7; // Using 4.7k and 1k voltage divider Serial.println(val); } Something like the code below must workout but unfortunately it does not help!
int sensorValue = analogRead(A0); voltage = ((sensorValue/ val) * 1023.); delay(1000); Serial.println("voltage: "); Serial.print(voltage); if (voltage<=215){ digitalWrite (led, HIGH); } else if (voltage>=215){ digitalWrite (led, LOW); } I cannot find the issue, it should work, i believe.
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const long internalReference = 1078L; //measured AREF to be 1.078 ~ 1.078*1000= 1078V void setup() { // put your setup code here, to run once: Serial.begin (115200); } void loop() { analogReference (INTERNAL); ADMUX |= B00000000; ADCSRA |= B11000000; //ADEN and ADSC equal to 1 (Start conversion) while(bit_is_set(ADCSRA, ADSC)); //Wait for conversion to end long val = ADCL | (ADCH << 8); //Get analog read value float voltage = (val/internalReference)*1024; Serial.println (voltage); } 
