Problem with executing udev rules for olimex's avr-usb-jtag

Question

I'm using Ubuntu 12.04 for programming purposes and recently decided to bring my previous atmel's micro-controller projects from Win to Linux. Namely AVR.

I installed the tool chain all right. It includes: avrdude binutils-avr gcc-avr avr-libc gdb-avr.

To test my connection to the micro-controller I used an olimex avr-usb-jtag programmer. When I plug it in and it is seen as /dev/ttyUSB0 (being an FTDI usb-com chip). The programmer is Atmel JTAGICE compatible.

Now when we try to

avrdude -p c128 -c jtag1 -P /dev/ttyUSB0 -t

And we get

avrdude: ser_open(): can't open device "/dev/ttyUSB0": Permission denied

So far it seems that without root's permissions we can't write nor read from the device. And it proves to be true when we actually try

sudo avrdude -p c128 -c jtag1 -P /dev/ttyUSB0 -t

The response is:

avrdude: AVR device initialized and ready to accept instructions
Reading | ################################################## | 100% 0.01s
avrdude: Device signature = 0x1e9781

Now I want to enable usual users (like programming IDE's for example) to access the programmer without giving them root permissions. The FIRST QUESTION for me is how to do that better?

I tried the udev approach and wanted the system to distinguish the plugged in device and apply permissions to the device file (ttyUSB0 by default for me). But the only option that worked was making a new file:

/etc/udev/rules.d/10-usb-avr-jtag.rules

It contained

KERNEL=="ttyUSB*" MODE="0666"

This configuration works, but I'm curious why something like this below doesn't work for me at all (the default ttyUSB0 is appearing, no rules are applied to the file)?:

SUBSYSTEM=="usb", ATTR{idProduct}=="6001", ATTR{idVendor}=="0403", MODE="0666"

Any ideas on how to make it work, or why it doesn't work at all?

Here's my output udevadm

Answer 1

If the former works, I suspect the latter should read

SUBSYSTEM=="usb", ATTRS{idProduct}=="6001", ATTRS{idVendor}=="0403", MODE="0666"