No GSM. Suspect dead Calypso. What to do?

danek daniel at
Sun Apr 12 05:14:18 CEST 2009

You need a 2.5mm 3-pole plug and then something to listen to the
115200 8N1 serial data coming the middle pole. This is 0..3V so you
can't just plug into serial port of your PC (which is -5..5V afaik). I
am trying to use my AVR microcontroller to do that but I was told a
MAX232 chip can do the conversion for you.

Please read the whole #1024 thread at --
it mentions how this cable can be built.

Unless I'm not looking carefully enough, all I can see is a pinout to the headers on the debug board (which I don't have) -- I'm assuming I can just wire this up to a DB-9 connector using the standard RS-232 pins for TX and RX, though you say that the voltage won't work... I'm assuming this would go for my USB-Serial adapter as well, since it is meant to take the place of a PC serial port. :(

I will have a look at the docs for MAX232... though if you have a link to detailed info (pinouts, plus schematic for any supporting components for MAX232, etc.) from anybody who has built a suitable cable using this IC it would be helpful.

Thanks again for your help and suggestions.
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