Serial reset with every new USB device

I understand the what the the auto reset feature is and what it is used for. However Every time a new USB device ( any device ) is plugged into the USB bus it triggers one of these auto resets. I've tried this on 2 XP machines and one windows 2000 and they all did this. However when I tried this on a Mac there was no auto reset. I did not think that this is the correct behavior, is it?

Is this a driver issue?

Is this operating system setting?

This is very inconvenient for my project!


Every time a new USB device ( any device ) is plugged into the USB bus it triggers one of these auto resets

Well. if the device is powered by the USB bus, then a reset is probably expected on power up. If resets are being triggered by other devices being pluged in to the USB bus, then you may need a powered USB hub to meet the power requirements.

Ok I seem to have figured it out.

I did a little research and found that if the Serial Enumerator setting was checked in the FTDI driver, then the control lines toggle whenever a new device appears on the same hub. This is what was toggling the the DTR line and causing the reset.

In order to get the setting to take I had to uncheck the Serial Enumerator option ( which was under the device manager -> USB Serial Port driver properties-> port setting ->advanced )then unplug and replug my Arduino.

I'm kinda surprised that no one has seen this before being that this was the default settings of the FTDI driver for the three windows machines that I tried this on?

You know what really pisses people off on this board is cross posting:-

Why so much grumpyness?

It seemed relevant to both categories to me.

Crossposting can be helpful if the message is of interest to a larger audience.

Had this info been more readily available, it could have saved me a lot of legwork. And as I actually did bother to do the legwork and provided the forum with some useful info I'm not really worried about it.

Why so much grumpyness?

Did you see his name? :wink:

But is his correct, cross-posting only cutters the forum and potentially pisses people off.

It's very annoying to spend time answering a post only to find that someone else already answered it in another forum. It can also lead to dead ends when searching.

Besides that, I think it's very uncommon for readers here that do most of the answering to limit themselves to certain sub forums.