AVR-Chat

On Tue, 2006-01-10 at 15:36 +0000, Richard Austin wrote:
> I have bought a STK500 and wish to program it/monitor it with my laptop. 
> Only problem is that the laptop only has USB ports. I've looked on the 
> group to find mention of USB>parallel or serial, but there does not seem 
> to be any definitive answer as to which ones work.

You don't mention the OS you are running. My guess is that you may find
better success (with the USB hardware) on Windows vs Linux or other OS.
But the safest thing will probably to go with something known to work or
make sure you can return something that fails.

I recently was playing with a board I made using a Mega8 talking to a
USB to RS232 serial device plugged into a Linux box. I was using the
"real" serial port for programming, and a USB to serial port for IO with
the AVR UART. All was fine at first when my AVR code only wrote. But
when I tried to read data from the computer it did not work. I tried
using this USB device with my AVR programmer and it did not work.

Next step was to jumper pins 7 & 8, and jumper pins 1 & 4 & 6. That
solved the problem of doing IO to the AVR UART. But the programmer still
would not work with this. By the way, I did disable flow control on the
computer side.

This USB to serial device that did not work with the programmer has a
label "DYNEX DX-UBDB9". I picked it up at Best Buy or Circuit City.

I then tried another USB to serial adapter that I had on hand and it
works fine with the programmer. This working unit is made by Iogear,
model "GUC232A".

If you need more ports the Keyspan four port (P/N USA-49WLC) USB to
serial also worked fine for programming.

All this is under Linux but I would be surprised if there were problems
with these under Windows. (Just all the other Windows problems.  Sorry,
can't resist.) So I don't view lack of RS232 ports on a device with USB
to be a serious problem.

Dale