barcode scanner emulator


Posted on Feb 6, 2014

Build primarily as proof of concept and because I found the challenge interresting, this little unit is able to send an ascii string terminated with a CR/LF via a RS232 connection. It`s emulating the transmission of a barcode and can be used with any kind of equipment that is expecting a barcode. I have been a little lazy on this project, as I hav


barcode scanner emulator
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e based it on the arduino serial V2 layout. This is also the reason I don`t have a neat schematic to show. But I have the reference schematic from the arduino board. And my handdrawn notes on the wiring and keypad. Please note that I have replaced the transistor version of the TTL to RS232 circuit with a MAX232 chip. This makes a more stable signal for the RS232 communication. Oh, and there is also a connection to pin1 on the SUB-D (not shown on the schematic) for supplying the BAR-X with a 5 volt from the RS232 port. (only available on specific equipment) And finally to make the whole thing work. Here is the sourcecode for the embedded program. Mind you it`s nothing fancy. I tried using some procedures to shorten the code. But it never worked So I took the sequential approach instead. /* * Barcode Emulator V0. 1 * * = * * A pre-defined ASCII code will be send * * using RS232 to a PC or other equipment * * connected via the serial connection. * * A Carriage Return(CR) and * * Line feed (LF) char will be appended. * * = * * Programmed by Rene Rasmussen 2011-09 * * This software released under the GPL * */ #include // define _delay_ms(). // for the delay to work correctly the compiler optimization must be set to -O2 #define UART_BAUD_RATE 9600L #define UART_BAUD_CALC(UART_BAUD_RATE, F_CPU) (F_CPU)/(UART_BAUD_RATE)*16L)-1) // wait ms Milliseconds void delay_ms(uint16_t ms) { uint16_t t; for(t=0; t<=ms; t+) _delay_ms(1); } void...




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