Arduino connection to Finger print sensor

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TheDevil
 
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Arduino connection to Finger print sensor

Post by TheDevil »

Hi,
First up, this is my first Arduino Project and also my first hardware project. Im actually a software engineer and my knowledge of hardware is limited.
I was following the tutorial at http://learn.adafruit.com/adafruit-opti ... int-sensor and I have made the wiring as it suggested there. The issue I am facing is that the finger print sensor is not on continuously. As in the orange light indicating that the sensor is on does not stay on. It just flickers from on to off when I make the connection. I have tried using a bread board to make the connection, use the different slots(if I can call them that) on the bread board and also tried to make the connection directly to the Arduino board with out the bread board, but the result is the same. The light in the finger print sensor comes on and then goes off. Any idea why this is happening and what I can do to fix it? Any help is appreciated.

Thanks.

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Franklin97355
 
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Re: Arduino connection to Finger print sensor

Post by Franklin97355 »

Could you post the actual code you are loading on the Arduino and the connections you are making between the scanner and the Arduino? Please use the

Code: Select all

 tags for your code. Are you sure the light is supposed to stay on?

TheDevil
 
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Re: Arduino connection to Finger print sensor

Post by TheDevil »

Yes, Im sure that the light is suppose to be on. The code is the one that is downloaded from github posted in that link. It is an example of how to read the input from the finger print sensor. I have not added/modified the code.Also, when the light is on, the output on the serial monitor shows "fingerprint sensor detected" whereas if the light is off (meaning the connection is not proper) there is no such message and it does not detect the finger placed on the sensor.

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Franklin97355
 
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Re: Arduino connection to Finger print sensor

Post by Franklin97355 »

Could you post a picture of your connections?

TheDevil
 
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Re: Arduino connection to Finger print sensor

Post by TheDevil »

The picture of the connections
Attachments
Connections for the sensor
Connections for the sensor
image.jpg (1023.94 KiB) Viewed 498 times

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adafruit_support_mike
 
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Re: Arduino connection to Finger print sensor

Post by adafruit_support_mike »

When you trimmed the insulation off the wires, was the exposed copper a single wire, or a bundle of smaller wires?

I don't have a fingerprint sensor on hand, but the wires for such units tend to be multistrand. Plugging multistrand wire into a header can be an iffy thing, and it sounds like your power connection isn't reliable.

Please post another photo of the ends of the red and black wires.. I'd like to see the part that actually goes into the header.

TheDevil
 
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Re: Arduino connection to Finger print sensor

Post by TheDevil »

I didnt trim the wires as they were already trimmed when I got the sensor. I dont have the sensor with me now as I am at work. Will post a picture once I get back home.

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adafruit_support_mike
 
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Re: Arduino connection to Finger print sensor

Post by adafruit_support_mike »

Please do.

Most devices with attached wiring do strip the free end of the wire, but only enough to make a solder connection.. usually around 3/16" of exposed wire. That might not be enough to make a solid power connection in the Arduino's headers.

TheDevil
 
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Re: Arduino connection to Finger print sensor

Post by TheDevil »

This is pic of the wire strands on the finger print sensor.
I am having the same issue with a magnetic stripe card reader, that I borrowed from a friend. It has a PS2 Connector so I used the second image to make connections and I provided connection to the GND and the 5V pin from the Arduino Board.The reader beeps and the lights on it also blink, but thats it. There is no response after this from the reader. Does this mean its a power supply from the issue? Do I need to get a new board? If yes, then how do I make sure that this does not happen in the new board?
Attachments
The PS2 connection pins.
The PS2 connection pins.
td_libs_PS2Keyboard_pins.jpg (80.62 KiB) Viewed 450 times
The Wire Strands.
The Wire Strands.
photo-2.jpg (225.95 KiB) Viewed 450 times

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adafruit_support_mike
 
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Re: Arduino connection to Finger print sensor

Post by adafruit_support_mike »

Try stripping a bit more insulation off the wires. You want about 3/8" of exposed wire in order to make a good connection in an Arduino header.

TheDevil
 
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Re: Arduino connection to Finger print sensor

Post by TheDevil »

I'll do that once I get home. Thanks. Hope that it works.

TheDevil
 
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Re: Arduino connection to Finger print sensor

Post by TheDevil »

So I stripped of some insulation on the red and the black cables and then connected it to the board. But its still the same result. Is this a problem with the board? Do I need to get a new board? How do I make sure this problem is not there in the new board?

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adafruit_support_mike
 
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Re: Arduino connection to Finger print sensor

Post by adafruit_support_mike »

I don't think there's anything wrong with the Arduino. The problems you've described sound like a loose power connection, and the fingerprint sensor has fairly small wires. It's a common enough problem that it's mentioned in the tutorial: http://learn.adafruit.com/adafruit-opti ... th-arduino

Solder about 1" of 22 gauge wire to the ends of each wire that comes out of the sensor, and plug that into the Arduino's headers. We know 22 gauge makes good connections.

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