fingerprint sensor doesn't work
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- lina
- Posts: 21
- Joined: Fri Mar 01, 2013 12:51 pm
Re: fingerprint sensor doesn't work
The time varies before the error message pops up
- adafruit_support_rick
- Posts: 35092
- Joined: Tue Mar 15, 2011 11:42 am
Re: fingerprint sensor doesn't work
How about the RX and TX leds?
If the error message does not pop up instantly, then that suggests to me that SFGDemo is trying to communicate with the sensor, but it is timing out.
That would mean that you have a problem with your connections. If I knew whether or not either of the LEDs was blinking, that might narrow it down a little.
Also, I asked before if the sensor flashes when you first apply power. Does that happen?
If the error message does not pop up instantly, then that suggests to me that SFGDemo is trying to communicate with the sensor, but it is timing out.
That would mean that you have a problem with your connections. If I knew whether or not either of the LEDs was blinking, that might narrow it down a little.
Also, I asked before if the sensor flashes when you first apply power. Does that happen?
- lina
- Posts: 21
- Joined: Fri Mar 01, 2013 12:51 pm
Re: fingerprint sensor doesn't work
Rx blinks tx does not. The red light comes on and off when arduino is connected to the usb port
- adafruit_support_rick
- Posts: 35092
- Joined: Tue Mar 15, 2011 11:42 am
Re: fingerprint sensor doesn't work
Alright. That means that the sensor has power, and that SFGDemo is connected to the Arduino and trying to talk to the sensor.
So, the problem is in the serial connection between the arduino and the sensor.
First of all, make sure the connector on the sensor is pushed in all the way. Here's what mine looks like: Next, try a different way of connecting the two serial wires to the arduino. I'll share my experiences with fingerprint sensor connections:
I soldered my wires to regular square header pins, and inserted those into RX and TX on my Uno - similar to what you have done. Believe it or not, this did not work very well at all. SFGDemo could connect, but it really didn't work at all for enrolling or scanning fingerprints.
So, I tried going through a small breadboard. With the wires still soldered to the header pins, I connected the sensor to the breadboard, and then used jumper wires to the Uno. This worked flawlessly. The lesson is that the serial connections from the sensor are tricky. You have to be certain that the connections are rock-solid.
Here's a couple of pictures of my breadboard (Ignore the GPS breakout board - it's not connected to anything...)
So, the problem is in the serial connection between the arduino and the sensor.
First of all, make sure the connector on the sensor is pushed in all the way. Here's what mine looks like: Next, try a different way of connecting the two serial wires to the arduino. I'll share my experiences with fingerprint sensor connections:
I soldered my wires to regular square header pins, and inserted those into RX and TX on my Uno - similar to what you have done. Believe it or not, this did not work very well at all. SFGDemo could connect, but it really didn't work at all for enrolling or scanning fingerprints.
So, I tried going through a small breadboard. With the wires still soldered to the header pins, I connected the sensor to the breadboard, and then used jumper wires to the Uno. This worked flawlessly. The lesson is that the serial connections from the sensor are tricky. You have to be certain that the connections are rock-solid.
Here's a couple of pictures of my breadboard (Ignore the GPS breakout board - it's not connected to anything...)
-
- Posts: 1
- Joined: Tue Apr 30, 2013 6:20 pm
Re: fingerprint sensor doesn't work
I have the same problem, the Rx blink but not the Tx.
- adafruit_support_rick
- Posts: 35092
- Joined: Tue Mar 15, 2011 11:42 am
Re: fingerprint sensor doesn't work
All I can do is to recommend the same solution.vincent1234 wrote:I have the same problem, the Rx blink but not the Tx.
Please be positive and constructive with your questions and comments.