Arduino breadboard with CP2102 module

I recently bought two of these Serial Converter USB 2.0 To TTL

Mainly because they were considerably cheaper than the FTDI adapter.
I have one installed on a breadboarded AT328 project I am working on.
The good news is - it works! (after downloading and installing XP drivers from Silicon Labs).

My problem however is this: It doesn't do the auto reset on upload OR if opening the Serial window. I have had a pretty thorough look through the forums, and it looks like the problem is that there is no DTR on the output pins. They are:
+5V, Gnd, Rxd, Txd, Rst and 3.3v. I can upload using the manual reset method, and I can run the Serial Monitor after a reset to get all the data stored, but it would be nice if it worked properly!
Any help would be much appreciated!

it looks like the problem is that there is no DTR on the output pins.

Yes this is the problem. The possible solutions are not easy. :frowning:

  1. Modify the drivers to toggle the RTS line when the port is open. However, I am not sure if the source code is available, I do remember seeing some at one time.

  2. Modify the arduino environment code to toggle the RTS line just after it opens the serial port. Source code is available.

  3. Hack into the converter and bring out the DTR line, it is on the chip but it is a small surface mount part and you might struggle.

Thanks Mike. The physical solution seems the most likely to succeed. DTR is pin 28, so at least it is on the corner of the very small chip!. Looks like it would be possible to solder a lead to it. When I find my close-up glasses ..... :-/