Thanks for coming back to this @peekay123!
Indeed, I recompiled my "FPS_IDFinger" sketch after adding some fingerprints with the "Enroll" sketch.
After that, it started to disconnect and blink green.
Even with the original example "FPS_IDFinger" sketch the same happens now...
To be honest I should say also that I changed the connections slightly: Instead of using 3.3V I now use 5V to power the FPS module.
I did not add any specific instructions in that direction.
Suggestion: Shall we focus on testing the standard example, included with your (old) library?
Here it is:
FPS_Enroll.ino - Library example for controlling the GT-511C3 Finger Print Scanner (FPS)
Created by Josh Hawley, July 23rd 2013
Licensed for non-commercial use, must include this license message
basically, Feel free to hack away at it, but just give me credit for my work =)
TLDR; Wil Wheaton's Law
This sketch will attempt to identify a previously enrolled fingerprint.
Modified for Particle Photon by Paul Kourany (peekay123), Oct 24, 2105
// Hardware setup - FPS connected to:
// digital pin 4(arduino rx, fps tx)
// digital pin 5(arduino tx - 560ohm resistor fps tx - 1000ohm resistor - ground)
// this brings the 5v tx line down to about 3.2v so we dont fry our fps
// Identify fingerprint test
int id = fps.Identify1_N();
if (id <200)
Serial.println("Finger not found");
Serial.println("Please press finger");
Today, I will try to find some time to try out a few more things.
1) I found also another similar thread where you helped making this device work: LINK
2) Here is the 'old' library ported by Paul: LINK