PCB_GPIO Input Signal 12v to Arduino

⚙ How the Module Works:

1. A 12V signal is applied to the +12 BUTTON terminal, passing through a current-limiting resistor before reaching the internal LED of the PC817 optocoupler.
2. When 12V is applied, the LED inside the optocoupler lights up, activating the internal phototransistor.
3. The phototransistor then connects GPIO to GND, generating a LOW logic signal on the microcontroller.
4. If no 12V voltage is present, the phototransistor remains off, and the GPIO stays at HIGH logic (depending on the pull-up resistor).

📌 Module Specifications:

✔ Input Voltage: 12V
✔ Output Voltage (GPIO): 3.3V / 5V (Depending on the microcontroller)
✔ Main Component: PC817 (Optocoupler)
✔ Galvanic Isolation: Separates the input signal from the microcontroller to prevent electrical interference
✔ Safer than direct input since it does not connect 12V directly to GPIO

🔗 Connections to Arduino / ESP32:

💡 Note: When using this module with an ESP32 (which operates at 3.3V), ensure a pull-up resistor is used or enable the internal pull-up (pinMode(pin, INPUT_PULLUP);).

✅ Benefits of Using This Module:

🔹 Protects GPIO from high voltage (12V to 3.3V/5V conversion)
🔹 Reduces electrical noise in the microcontroller system
🔹 Isolates the sensor circuit from the main system, minimizing damage risks due to voltage spikes