On Sun, 15 May 2011 14:20:16 Nick Rout wrote: > On Sun, May 15, 2011 at 2:45 PM, Steve Holdoway <[email protected]> wrote: > > http://www.newit.co.uk/forum/index.php?topic=1810.0 any use?? > > Certainly worth bookmarking for the future, but you can't get the > serial console without the proprietary jtag connector. > > However I wonder if I can jimmy one up. The device has two ports that > plug into the jtag box. One is a 'uart' connector, the other is > specifically for jtag. The proprietary box seems to serve two > purposes, a proper jtag connector AND a gateway between the uart port > on the device and a ftdi serial usb chip. So... I guess someone with > knowledge of the pinouts on the 4 pin uart connector, and some > electronics nous could try and get the serial part going...
Hi Nick, The adapter kit is US$39. It's hardly expensive. This wiki indicates the order of the 4 pins in the serial connector (at the bottom of the page): http://www.plugcomputer.org/plugwiki/index.php/GuruPlug If you only need the serial interface (not the JTAG) then you could probably hack a USB->RS232 converter. Inside the converter (an FTDI one would be best) is a USB UART chip and a level shifter. The UART deals with the USB interface and the RS232 protocol. There are three key wires between this chip and the level shifter: Data In, Data Out, and Ground. The level shifter simply converts the 5V or 3.3V from the USB UART into +/- 12V or so needed by a true RS232 device. If you buy a converter you need to peel off or crack open the case and identify the two chips. Find out if the level converter is running at 3.3V or 5V, and the model number of the FTDI chip (the USB UART). If the level converter is running at 3.3V then you can hook up two wires directly from the Data In and Data Out pins on the FTDI. You also need a Ground wire. Run these to the serial connector on the GuruPlug. (You don't need the 3.3V wire). If the level converter is running at 5V then remove it and discard it. Find out which pin on the FTDI chip sets the output to 3.3V and change it, then hook up Data In, Data Out and Ground as above. Assuming you don't need another level of inversion this should give you a console interface on /dev/ttyUSB0 ...or buy the kit. Andrew Disclaimer: I don't own a GuruPlug and I've never tried this procedure. I have looked at changing an off-the-shelf FTDI USB->serial converter to run at 3.3V to hook up to my radio. I think I know what to do, but I didn't do it yet. _______________________________________________ Linux-users mailing list [email protected] http://lists.canterbury.ac.nz/mailman/listinfo/linux-users
