dyanf
Posts: 1
Joined: Wed Jan 23, 2013 8:56 am

Clock and Data card reader

Wed Jan 23, 2013 9:02 am

Hi Guys,

I purchased my pi yesterday and loving it.

A project I want to start working on is reading data from a "Clock and Data" proximity card reader.

Now my main question is, can I just hook the card reader up to the serial port?

It basically has two wires for data. Data + and Data -. It needs 12V of power which I supply separately.

Hope someone can help, and I look forward to being able to contribute as well.

Regards

prairietech
Posts: 28
Joined: Wed Mar 20, 2013 9:22 pm

Re: Clock and Data card reader

Wed Apr 10, 2013 2:14 pm

I'm interested in doing the same thing. Since there haven't been any replies since your posting in January, this might be uncharted territory?

My application would only involve no more than 6 cards. Scheduling or an audit trail would not be required but more likely not too hard to implement. I have cards that are used for another commercial access system and a spare HID ProxPoint reader.

Maybe my reply will spark some interest or replies?

danneman
Posts: 19
Joined: Thu Jun 21, 2012 9:57 am

Re: Clock and Data card reader

Wed Apr 10, 2013 4:15 pm

You probobly need a levelshifter of some kind because raspberry only talk 3.3V.

Read the manual for your proxy reader but I guess it is 5V and that will kill your Pi.

/Daniel

MangoKid
Posts: 53
Joined: Tue Apr 02, 2013 12:24 pm

Re: Clock and Data card reader

Wed Apr 10, 2013 5:39 pm

If the card reader you are using has a D+ and a D- line that means it is a USB device. For this you can get a USB breakout board from almost any online electronics store and plug it right into the PI. If you put these wires into a serial port you will get nothing and chances are you may damage the device with +12v on the TX pin of a serial port.

danneman
Posts: 19
Joined: Thu Jun 21, 2012 9:57 am

Re: Clock and Data card reader

Wed Apr 10, 2013 5:58 pm

Yes, D+ and D- sound like USB but Clock And Data is not USB.

Clock And Data is a common protocol for Prox anf Magstripe readers. One Clock signal and one data signal. Normally with TTL levels.

/Daniel

MangoKid
Posts: 53
Joined: Tue Apr 02, 2013 12:24 pm

Re: Clock and Data card reader

Wed Apr 10, 2013 8:01 pm

okay that is probably an SPI or and I2C interface. This can not be run into a serial port. There are some FTDI chips which will turn these signals into something interpretable by your computer.

such as -> http://www.robotshop.com/devantech-usb- ... mpaign=jos

User avatar
joan
Posts: 14755
Joined: Thu Jul 05, 2012 5:09 pm
Location: UK

Re: Clock and Data card reader

Wed Apr 10, 2013 8:34 pm

dyanf wrote:Hi Guys,

I purchased my pi yesterday and loving it.

A project I want to start working on is reading data from a "Clock and Data" proximity card reader.

Now my main question is, can I just hook the card reader up to the serial port?

It basically has two wires for data. Data + and Data -. It needs 12V of power which I supply separately.

Hope someone can help, and I look forward to being able to contribute as well.

Regards
Could this be a Wiegand interface device? If it is search the forum for Wiegand.

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