Fingerprint Sensor GT-511C1R is Not Communicating with Arduino Uno

Recently I bought a GT-511C1R fingerprint sensor to use in a project where it will unlock my front door. This is the site where I got it from: Fingerprint Scanner - TTL (GT-521F32) - SEN-14518 - SparkFun Electronics
I used the JST SH cable to and a voltage divider circuit to connect to the arduino uno which connects to my computer. On the Sparkfun website there is a demo software which can be used to download fingerprints directly to the sensor, however this software does not work for me. I have watched all of the videos on youtube, so I've put it in the correct baud rate, port, and clicked open, yet it still does not work. This is my first problem.

After that I tried to test to see if the sensor is even working so I downloaded multiple libraries and tried testing to see if the LED inside of it would blink using the code provided by many websites. It did not blink, however I do know that I wired the circuit correctly and the green indicator light is telling me that it is still receiving power despite the fact that it is not communicating with the Arduino UNO. The only time that the LED on the sensor blinks is when I plug it in, and even then it only does it once. This tells me that the sensor still works. I know that the arduino is communicating with the computer because the sample blink sketch that arduino provides makes the LED blink, however I don't know how to make it communicate with the sensor.

I do not know why the demo software isn't working, which is a big mystery for me. The multiple libraries that I have downloaded for the GT-511C1R don't work when I try to upload them as a library in the arduino. The one that was made for the GT-511C3 did actually work, but it still doesn't communicate with the FPS. I've also heard differen't things from different sites. Some say that the library for the GT-511C3 works with the GT-511C1R, while others say it doesn't.

These are the sites with the libraries that actually did download for me: http://wordpress.hawleyhosting.com/ramblings/?p=375

There were many other libraries made specifically for the GT-511C1R that I tried but none of them worked. Also communicating with serial did not work either. I tried doing the tutorial I got from this website too: http://startingelectronics.org/articles/GT-511C3-testing/ I didn't get anything in the serial monitor when I tried that.

Any help would be greatly appreciated. Thanks!

I was able to get the sensor to blink finally! I have no idea why it wouldn't before and I didn't change anything. I found which library works, and all of the others do not. It turns out that the only one that worked was the original one for the C3. That answered a few of my questions.

Now my only questions are why doesn't the demo software work and how can I communicate with the sensor using the serial monitor? I don't know what to type in and nothing makes the serial monitor do anything even after I selected the correct port.

I am using the same setup, Arduino Mega with the GT-511C1R, and I was having the same issues, earlier today I found this article:

http://sparkfun4.rssing.com/chan-8965065/all_p1252.html

About halfway down it says to switch the pins from (4, 5) to (10, 11) I tried when I got home and I was able to make the blink program work finally, I have yet to try anything else but I hope this will at least help someone and set them in the right direction.

Hey guys,

@Ben - thank you for opening this topic. I had the exact same problem.

@Jaqueel - thank you A LOT! I spend many hours overdoing the same scheme (which I knew was correct) without success of course. Thanks to your advice, I got the blink example works.

Just an advice to anyone, who's bumping his head - after you follow Jaqueel advice, even if the Blink example still does not seem to work, upload the example a few more times, and try disconnecting the FPS from the arduino before the upload process starts. And that kind of hacky stuff. For some reason, I needed to do that and kind of flush something in order to the FPS to start blinking.

Best to you guys!

Just an update for anyone who can help, I’ve managed to get the blink sketch to work. I downloaded the correct library for the C3 and it works now. The SDK Demo software now works if I upload the XBee Shield sketch that I got from this website XBee Shield Hookup Guide - learn.sparkfun.com The Enroll sketch and ID sketch still don’t work though. The blue light turns on but nothing shows up in the serial monitor. Serial communication works for other sketches but not for this one. Anything would be helpful.

Still I'm having a trouble in compiling it. it always leads lead to result of:

FPSBlink.ino:12:25: error: FPS_GT511C3.h: No such file or directory
FPSBlink:20: error: 'FPS_GT511C3' does not name a type
FPSBlink.ino: In function 'void setup()':
FPSBlink:25: error: 'fps' was not declared in this scope
FPSBlink.ino: In function 'void loop()':
FPSBlink:33: error: 'fps' was not declared in this scope

thank you for your answer.

FPS_GT511C3.h: No such file or directory

That means it didn't install/use that library.
Leo..

Do you know where i can found the library that works? still all the library i found didn't work with arduino uno. I installed the library but still can't compile it. Thank you for your help

Not a good coder here. I tried installing the library files the “include library > add zip” way.

Didn’t work. So I copied the .ccp and .h files inside the sketch folder.
Now the sketch compiles.
Leo…

BenRosenberg4:
I was able to get the sensor to blink finally! I have no idea why it wouldn't before and I didn't change anything. I found which library works, and all of the others do not. It turns out that the only one that worked was the original one for the C3. That answered a few of my questions.

Now my only questions are why doesn't the demo software work and how can I communicate with the sensor using the serial monitor? I don't know what to type in and nothing makes the serial monitor do anything even after I selected the correct port.

I am having the same problem. Can you post the link to the working library?

Hi, everyone.

During my last project with fingerprint technology, I ended up with quite a few of these exact (GT-511C1R) sensors. They are all new, unused, in mint condition. Since my current project aren't within the fingerprint field, I'm willing to sell them to anyone who'd be interested in using them.

Shoot me a private message/email if you're interested.

Regards,

tilen

I wrote this after some trouble with the Sparkfun libraries last year.