On Sat, 7 Oct 2006, Greg Thomas wrote: SNIP > Any links for details on the serial line driver chip mod? > > Greg
A lot of embedded h/w has at least one serial port available on the system board, however most vendors went cheap and didn't provide the serial line driver chip. So what you get to do is build an rs232 serial cable using either a max232(5v) or max2323(3.3v) chip. BTW, you may get lucky and find a max232 onboard, if so all you need to do is build an ordinary serial cable. I start with the obvious, look for a 4 pin header or 4 pads close together that look like a header should be there. While the power is off use your trusty ohm meter and find out which one of the pins/pads are connected to ground. Now power up the board, and using your new found ground see what the voltage is on the other 3 pins, look for one that is either 5v or 3.3v. Once you have pwr/gnd you have a 50/50 chance of picking Tx/Rx corerctly, actually you have a better than 50/50 chance, 'cause you'll probably see a little bit lower voltage on the Tx pin and nothing on the Rx pin. Anyway, there's lots of information on how to build a serial cable for embedded systems on the web. have fum hacking diana
