John Rehwinkel wrote: >> I simply couldn't get avrdude to >> "find" the device named usbtiny on my Fedora 7 (linux) box. (I built a >> USBTinyISP programmer, produced as a kit by Limor Fried.) It doesn't >> work when I m an ordinary user. I think that is significant because >> running `lsusb` as a user will not show me any output, but running >> `lsusb` as root will. > > That's your clue. It's a permissions problem. Probably the USB node > in /dev is owned by root and not read/write by other users. There's > probably a way to configure the driver to create nodes usable by > everybody. > >> Well, I had gotten my feet wet with the code, and I suppose that is a >> good thing. I have a feeling there are not too many people who use >> avrdude on Fedora 7 and it hasn't had an extended amount of testing as a >> result. > > That may be the case. I use it on MacOS, which is a BSD variant, an > entirely different code tree than the various Linuxes. > >> Bob Cochran >> Greenbelt, Maryland, USA > > Heh, I'm local to you (northern VA)! > > -- John > > > Hi John,
I'm glad we are local to each other. Maybe we can meet some time. Preston suggested I try the usbtiny programmer on Windows XP and it turns out it at least initializes the target device normally. Here is the sequence of my actions: 1. I booted to XP and logged into my user account (which has administrative privileges...) 2. I plugged the usbtinyisp programmer into an powered USB hub. The programmer in turn is connected to an AtMega644 circuit on a breadboard. The breadboard circuit isn't powered on yet. 3. The green LED goes on to my great pleasure! 4. In a command prompt I issued `avrdude -c usbtiny -p m644' 5. avrdude is able to talk to the programmer, but not the Mega644 since that circuit isn't powered on. 6. I connect power to the ATMega644 circuit. 7. issuing `avrdude -c usbtiny -p m644' now results in avrdude saying it can't find the usbtiny device. 8. I disconnect the usb cable from the usbtiny device, and connect it back in again. 9. issuing `avrdude -c usbtiny -p m644' now results in avrdude connecting to the ATMega644 and reporting that initialization succeeded and the fuses are okay. That is, it suddenly works fine. I'm using a 6 foot long USB cable. I am using the 'AVR breakout board' (SKU BOB-08508 from Sparkfun Electronics on http://www.sparkfun.com/ ) so that I can connect a 10-pin IDC connector to it and plug this directly into my breadboard with the ATMega644 circuit. I have the breakout board connected to the power and ground on the breadboard. Breakout Board's Reset pin is connected to pin 9 of the Atmega644 Breakout Board's MISO pin is connected to pin 7 of the Atmega644 Breakout Board's SCK pin is connected to pin 8 of the Atmega644 Breakout Board's MOSI pin is connected to pin 6 of the Atmega644 Pins 10-11 on the AtMega644 are connected to VCC and ground. Each pin has one leg of an 0.1uF ceramic capacitor (marked "104Z") installed on it to smooth out the VCC. Pins 30-31 are connected to VCC and ground, the same as above, complete with ceramic capacitor. Pin 4 (PB3) is connected to an LED which is connected to a 150 Ohm resistor. All other ATMega644 pins are left floating. I wish I could test the usbtinyisp programmer for soldering defects of my own making...I'm not sure why avrdude can't find the programmer after I connect power to the Mega644 circuit. But it does find the Mega644 once I unplug and replug the USB cable. Now to continue testing this in Linux! I really want to do AVR development from a Linux account and I plan to submit a "Bugzilla" bug to the Redhat people because avrdude as installed doesn't seem to work for unprivileged users. Also, I think the USBTinyISP device can stand a little more testing as a circuit. The reason for wanting Linux to work doesn't really have noble open source roots...I just don't want to have to set up the laptop again and again each time I want to test something. Kindest Regards Bob Cochran > _______________________________________________ AVR-chat mailing list AVR-chat@nongnu.org http://lists.nongnu.org/mailman/listinfo/avr-chat
