Hacking LS 2208 barcode Scanner

LS 2208 is very rugged bar-code scanner. It is also very versatile capable of generating various output formats like USB, RS-232, IBM 468x/469X etc.  But to use these it needs special wires to do so, on one end there is a RJ50(10p10c) which connects to the scanner, and the other end there can be USB or DB-9 or PS/2 connector. I bought a second hand scanner and only wire came which was a  USB. First thought was to use a RJ50 and make my own wire, but RJ50 is a very rare item here, many computer vendors didn’t even have heard  of it, and one guy told me such a thing doesn’t exist. At the end I opened it up, which was not a walk in the park, took out the circuit and soldered the wires and dremelled an opening.  The scanner uses a Renesas 16bit micro of H8S/2215 group.

Here is the pin out for various interfaces:

Screenshot from 2014-05-19 16:27:07

To use the interface, you have to scan a bar code from the user manual.

Here is a gallery of pictures

So I powered up the scanner and  makes some beeps, connected to the TX line to USB UART(CP2012) board. And I get junk values,  the same junk every time, I scratched my head too long. In comes the Open Bench Logic Sniffer. Updated its firmware and downloaded latest client, hooked up the tx line to channel 0. Scanned it, saw the signal, opened up the UART analyser, same junk there again. Then I inverted the signal and analysed it again in the client, and lo and behold got the sweet sweet data. So hooked up a 7404 and it was golden. With the data at TX line one can do pretty much anything with it. Hook it up with an arduino and display stuff on LCD.

Here are some screen shoots with junk values

Screenshot from 2014-04-14 18:04:42

Screenshot from 2014-04-14 18:06:32

Garbage data and correct data. I just changed the bit encoding.