User talk:Mrnuke

BM857 PC interface cable

I'm trying to build a PC interface cable for my Brymen BM857. I have used Radioshack 276-142 IR diode and photo-transistor set, and a PL2303 USB to serial converter.

If you have a real cable you'd like to donate, hop on to #sigrok and contact me.

Info

This is an experimental homebrew design. It does NOT work. It is yet unclear which of the following reasons, if any is the cause

• Photo-transistor and/or diode do not support 9600 baud reliably
• The BM857 uses a different wavelength
• The value of the photo transistor pull-up resistor is too high (too sensitive) or too low (not sensitive enough)

TODO

Schematic

Photos

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  The IR diode and phototransistor are prominent on the board

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  Board being held in place by the rubber holster