Computer Interfacing
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Magnetcard reader/writer

Magnetcard reader/writer


       Computer Interfacing Forum Index -> General electronics
Author Message

Aug 24, 2008 3:18 pm

Recently i started experimenting with a MSR(Magnetcard reader/writer)

I bought a cheap reader with 3 output signals of which only 2 are used, data and clock.
Commercial devices are sold with a keyboardwedge, something like an interface

I have cut a 5 wire cable with a 5pin din plug, male and female, into two parts, connected the wires and soldert them on a peace of coperplated epoxy. with an 5 pin header, to connect the cardreader.

The purpose is to emulate a keyboard with the reader, that is, al data from the reader,( card data !!) appears on screen.
But no dice, it does not work quit well, it blocks my keyboard.

data and clock of the reader are connected to keyb data, and keyb clock.
I have not tried it yet, but could it be a data problem, something like inverted data and clock

Any one who has an answer? see also my wedge topic
Site Admin

Joined: 13 Mar 2007
Posts: 145
Location: Netherlands and Kazakhstan

Aug 25, 2008 7:39 am

I have had problems with commercial barcode scanners and wedge interfaces in the past. The barcode scanner worked when connected directly to the computer, but refused to work when the keyboard was also attached. After much testing it appeared to be caused by cable length. Reducing the cable made both the scanner and keyboard work. Unfortunately in that setup a cable of minimum five meters was necessary to make the application work in practice so we had to change the whole setup with the scanner separately connected to an RS232 port of the computer.
Junior Member

Joined: 28 Mar 2011
Posts: 20

Mar 29, 2011 12:59 am

May i ask where you get the cheap msr ? Is it available online to purchase, i need one for my next experiment.

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