Hello everyone, I’m working on a fingerprint-based attendance system using an Arduino UNO and the R307 fingerprint sensor. I have connected all the wires correctly, written the code, and uploaded it without errors. However, the fingerprint sensor is not responding at all — no LED, no serial output,…

R307 Fingerprint Sensor Not Working with Arduino UNO – Need Help Troubleshooting

manojhitkari July 18, 2025, 7:47am 5

Hi Tom George

please suggest me