Hi guys, I just would like to detect the power of charger when connected. I saw few recommendations to use a voltage comparator but for simplicity and reduce component I'm finding simpler. I try this: [Untitled] Why it's not working? :face_with_raised_eyebrow: even with a Vout voltage close to 5V (4.5V). Maybe because it's not an analog pin? Edit: const int INTERRUPT_PIN = 2; // Set interrupt pin void setup() { pinMode(INTERRUPT_PIN, INPUT); attachInterrupt(digitalPinToInterrupt(INTERRUPT_PIN), chargerConnected, RISING); Serial.begin(9600); } void loop() { // Check if chargeis connected Serial.print(digitalRead(INTERRUPT_PIN)); delay(1000); } void chargerConnected() { // Interrupt service routine // Charger is connected, handle it here Serial.print("UP"); }

I do not know what I did wrong from my first circuit (post #19) but it's working now. [image] const int INTERRUPT_PIN = 2; // 2 // Set interrupt pin volatile bool temp = false; void setup() { pinMode(INTERRUPT_PIN, INPUT); Serial.begin(9600); attachInterrupt(digitalPinToInterrupt(INTERRUPT_PIN), chargerConnected, RISING); } void loop() { // Check if chargeis connected Serial.print(digitalRead(INTERRUPT_PIN)); Serial.println(temp); delay(1000); } void chargerConnected() { // Interrupt service routine // Charger is connected, handle it here temp = true; // digitalRead(INTERRUPT_PIN); Serial.print("up"); } Thanks All!

Do you mean it won't work if separated power source?

[image] paulpaulson: Consider this voltage monitor sketch. constexpr uint8_t PotPin {A8}; constexpr uint16_t LowVoltage {1000}; // milli volt It could work if i check it constantly, but i would like to use interrupt because i will be in sleep mode.

Yes. To wake up the Arduino is one task. The scond is to run the voltage monitor. These are two different task to be done. Or I´m wrong? confused

Do you have a common ground now???

Euhh actually no because it's a separated power source.

[image] Common ground and why you need one General Electronics A common mistake for people new to electronics is to have 2 circuits fed from different power supplies with signals passing between the circuits, but with the grounds not connected. This leads to questions asking why the project doesn't work. You don't have to spend long reading the questions on this forum to see this is asked often. Here I attempt to explain the problem and why it matters to connect the grounds. Note that in all of the schematics that follow I have used a battery as a power sup…

Good reading, I admit I always warring to mix connections of different voltage. Is it risk if voltage battery is higher than voltage supported by the Arduino (12V BAT for example)? I still need to read about common ground. [image] Now HIGH detected in loop with 2.5V but interrupt still not working (even with 4.55V).

Maybe add a push button in your battery line. You are waiting for a rising edge. But it is already high before you start your sketch.

I already change for easy testing to: attachInterrupt(digitalPinToInterrupt(INTERRUPT_PIN), chargerConnected, HIGH);

Try digitalread and boolean variable in your interrupt. Temp is now a 2 byte variable. The next interrupt may change it during reading... You now may have a million interrupts per second... So the rising edge combined with the button might be an option.

How to interrupt Arduino with voltage input?

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PerryBebbington April 14, 2023, 6:44am 18

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How to interrupt Arduino with voltage input?

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