Arduino based Fire Alarm – Circuit and Working Fig. 2 presents the circuit diagram for the fire alarm using a flame sensor and Arduino Nano. The system is powered by a step-down transformer (X1), a ...

Build Your Own Arduino Voltmeter Circuit and Voltage Divider Which Can Measure Voltages From 0V to 30V, Including 12V. Visit To learn More. ... in the circuit diagram provide some over-voltage ...

Voltage Divider Circuit: Safely steps down the battery voltage to a range compatible with the Arduino’s ADC. Low Battery Alert: Activates a buzzer/LED when voltage falls below 3.8V. Display Output: ...