Arduino Fingerprint Project Help Please!!

I am a beginner and using Arduino Uno, a fingerprint sensor and a servo motor to build a door lock (school science project). I followed many videos and tutorials which are pretty much the same, use the same code. I am using R307 fingerprint module.

The project looks like this https://youtu.be/9Uo8IhTL7zM


I used this library https://github.com/adafruit/Adafruit-Fingerprint-Sensor-Library

I followed this code for servo https://pastebin.com/ps2sgykY

enter image description here

The project works as far as enrolling fingerprint. It can detect, store and recall fingerprints. But the problem is, none of these work for the servo the way it should work. The servo motor rotates automatically even if I touch the yellow wire with my hand. And when the servo is connected to the board (yellow wire, pin 6 or 9 (corrected accordingly in the source code), as soon as I upload the code, it starts spinning automatically. I want the fingerprint sensor to work as a toggle switch for the servo, as shown in the video. But the servo starts automatically and when I place my finger on the sensor, sometimes it stops for a little then starts spinning again. The sensor doesn’t even work repeatedly after this.

Any solution?? As I said, I need the sensor to work as a toggle switch that turns on and off the servo. This code is used almost in every tutorial and they show it works, I did exactly what they say, but clearly something is wrong.

  • Can you show us he sketch you're using? – VE7JRO Sep 30 '19 at 18:40
  • Do you have a contineous rotation servo? – chrisl Sep 30 '19 at 18:47
  • I am using the same sketch as the picture attached in the post, just the RX and TX wires are connected to the 2 and ~3 pins, not on A4, A5. As shown in the first video link, I followed that. – Omar Khalid Shohag Sep 30 '19 at 19:02
  • The servo I am using is TowerPro SG91R – Omar Khalid Shohag Sep 30 '19 at 19:03
  • make the servo work correctly with an input from a push button first .... add the code for the reader afterwards – jsotola Oct 1 '19 at 3:04

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