Tuesday, November 22, 2011

ftdi232 permission on Ubuntu

I'am using the ftdi chip with bitbang mode to control some hardware with linux.
Every time I copy my software to a new desktop, it always take me hours to figure out why it has no permission to run the bitbang mode as a regular user.
Every website or forum I look around tells me about the udev, but I check back on the working desktops and there is no udev rule for the ftdi hardware. And after trying to force permissions with chgrp and chmod directly on /dev/bus/usb/* I figured out that I had to master at least a little about udev rules.

Checking with a little more care at a working machine I´ve found a Virtualbox instalation which created a udev rule for the virtualbox usb driver. Changing that rule to be used with the FTI chip I do the following steps, with had worked perfeclty:

Create the file /etc/udev/rules.d/10-ftdi.rules

Write on it:
SUBSYSTEM=="usb_device", GROUP="dialout", MODE="0664"
SUBSYSTEM=="usb", ENV{DEVTYPE}=="usb_device", GROUP="dialout", MODE="0664"

I have to make sure my user belongs to the dialout group, reboot the machine and that´s done.

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