Objective Development Forums

ok, I've resoldered everything and it works like a charm the 54kOhm between VCC and GND on the ISP side were not because of a faulty capacitor, but because of the 22kOhm and 33kOhm resistor that are between there took me some time to figure that out anyways, I'm happy that it works now and while I'm...

forgot to log in again
the post above is from me...

There is definately no wiring error on the AVR-Doper - I've checked it so many times... I don't think the new type of wire will be better for the circuit neither, but "Klingeldraht" is way easier to solder than "Litze" and you can control its path on the PCB much better. That's w...

I am such a fool, I had VCC and GND exchanged on the AVR to be programmed. I hope I didn't do any damage - I corrected the mistake, but the described behavior still applies. The AVR Doper is not recognized when the other AVR is attached to it, but it is recognized when it is alone. AVR Studio also r...

There is a 0.1µF ceramic capacitor between VCC and GND on the AVR-Doper and it is very close to the AVR. I didn't have a capacitor between VCC and GND of the other AVR though, but I have a capacitor between each connector of the quarz and GND - both on the AVR-Doper and the other AVR. I'll try if it...

ne, ich hab nen andern ATmega8 auf n Steckbrett gesteckt, Quarz und 2 15pF Kondensatoren dazu gesteckt und das dann an den AVR-Doper angeschlossen. Den Jumper für "Provide ISP supply" hab ich gesetzt und dann das ganze Gespann dann an den Laptop angeschlossen (nirgendwo ne externe Stromver...

hm, I guess it has to do with the brownout - I just tried to program another ATmega8 using the AVR-Doper and I set the jumper to provide the ISP power supply and when I connected the device to my laptop it was not recognized at all (Gerät wurde nicht erkannt), but when I connected it again to the la...

um, now that you mention it bad routing could definately be a cause if it can lead to such behavior - that was why I was thinking about re-wiring the beast in the first place... I'll check for differences in the voltage and if there are none I'll get out my soldering iron again and re-solder that th...

I don't have an oscilloscope, but I do have a multimeter - I used it to check that there are no short circuits and that everything is connected the way it should be that was me - I didn't notice that I was not logged in anymore... PS: I looked up what you meant by EMI problems - I don't think elect...

hm, sorry, I don't know what EMI problems are, but I've checked the soldering more than a dozen times. I have also no Idea what you mean by coupling to the RESET line - I guess you mean that the AVR gets a reset signal in the middle of working. I don't know where that should come from, but I'll chec...

I am not sure if both modes really do work, because I didn't have the chance to program an AVR with the device yet - I'm building a PCB at the moment that will have an ATmega8 that I will try to program with this home-made AVR-Doper. All I can say for sure is that I can get the device to be recogniz...

I just tested without the 74HC126 - same behavior
so it is not the 74HC126?
that's good because I don't have to replace it, but what else could it be if neither the buffer nor a capacitor, resistor or diode?

I've just re-checked everything: I made sure everything is connected exactly the same way as it is on the plan, I've made sure all solder joints are ok and still ist shows the same behavior that I described in the initial post. I've checked that there is no short circuit anywhere, too. Could it be s...

I definately have the 74HC126 chip - at least that is what the bill says and what is printed on the IC. Would a wrong buffer chip also account for the device not even being detected when the jumper is not set? Can you imagine anything else causing this behaviour? I could of course just hardwire what...

Hi, I've built the AVR-Doper without the HVSP parts accorfing to the schema found at http://www.rototron.info/?Page=USBAVR/USBAVR.aspx and it works - kind of... When the HID jumper is set, AVR Doper is recognized in CDC mode. When the HID jumper is set and I connect pin 27 of the ATmega8 to GND with...