> Greg London wrote: >>> ...the designer is using AC coupling. Perhaps that's obvious. When DTR >>> goes low, it'll briefly pull down the micro's reset pin. >> >> The AC coupling I understand. > > OK, good. Just to flesh out the rest of the thought to anyone for whom
20 years as a digital engineer... Most of that time spent on crazy, highly complex cores that were part of an even larger, crazy complex ASIC/SOC. This is the first time I've fiddled with an Arduino. I got a starter kit and ran through a bunch of sketches and breadboarded some proof of concept things. It's also the first time that I needed to understand serial. I've work a lot with 32 or 64 bit wide internal busses that handle out-of-order pipelined arbitration. Just never got around to learning serial. ;/ >> I have read some people disconnectiong the USB FTDI DTR/RTS >> pin from the atmega reset... > > Did they say why? Given lots of people are using these FTDI chips with > the DTR attached this way, there should be plenty of reports of flaky > behavior, if that's what is happening. I can't remember. I've been cramming through websites trying to soak up everything I need to know to put an unprogrammed atmega into my own design and turn it into something that can be programmed as if it were an arduino. It might have been because they had RTS connected to reset instead of DTR. Maybe? Can't remember for sure. Connecting DTR to the reset of the atmega chip via a surface trace that can be cut with exacto knife would be cheap insurance. If it works, no sweat. If it has a problem, a quick cut should fix it. Greg _______________________________________________ Hardwarehacking mailing list [email protected] http://lists.blu.org/mailman/listinfo/hardwarehacking
