Linux

• Show git Branch in Shell Prompt

  Jan 20, 2013

  Being able to see which git branch you are working on right in your bash prompt is extremely helpful!

  

• Raspberry Pi WiFi

  Nov 14, 2012

  The Raspberry Pi is a $35 single-board ARM computer that runs Linux. If you don't yet have a Raspberry Pi, you can either order Raspberry Pi from Newark/Element 14 and get on in line waiting for the next batch or pay way too much for a Raspberry Pi from Amazon.com.

  Here are two nano-sized, low-cost, USB WiFi adapters that I have verified work on a Raspberry Pi ("Wheezy") right out of the box.

  

  The AirLink101 AWLL5088 Wireless N (0bda:8176 RTL8188CUS 802.11n WLAN Adapter) is shown on the left and the Edimax EW-7811Un Wireless N (7392:7811 EW-7811Un 802.11n Wireless Adapter Realtek RTL8188CUS) is shown on the right.

  Both of these WiFi adapters are based on the Realtek RTL8188CUS chipset. Drivers are built-in with Raspberry Pi Raspbian ("Wheezy"), the debian-based distro used by most beginners.

  Not only are they based on the same WiFi chipset, they are virtually identical in size too. These are "nano" sized which means they're not much larger than the USB connection itself.

  Since the Raspberry Pi only has 2 USB ports, you're most likely going to want to get a powered USB hub as well. That will allow for a mouse, keyboard, and the WiFi adapter with additional ports available for more devices.

• Setting USB Permissions for USBtinyISP in Fedora

  Aug 09, 2012

  If you try to use the USBtinyISP USB AVR programmer as a regular user in Fedora, you will get a permissions error like the one below.

  avrdude -p m328p -c usbtiny -e -U flash:w:test.hex
  avrdude: Warning: cannot open USB device: Permission denied
  avrdude: Error: Could not find USBtiny device (0x1781/0xc9f)
  
  avrdude done.  Thank you.

  In order to use the USBtinyISP without becoming root you will need to add a udev rule that gives regular users permission to use the device.

  su
  echo "SUBSYSTEM==\"usb\", ATTR{product}==\"USBtiny\", ATTR{idProduct}==\"0c9f\", ATTRS{idVendor}==\"1781\", MODE=\"0666\"" > /usr/lib/udev/rules.d/99-custom.rules
  udevadm trigger
  

  You should now be able to use the USBtiny with avrdude as a regular user.

• CadSoft Eagle 6.2 in Fedora 17 x86_64

  Aug 02, 2012

  I've been using CadSoft Eagle in Linux for years. But it's been a little while since I've had a chance to tinker with my robotics projects. Turns out the installatin isn't quite as simple as it once was. Here is how I got Eagle running in 64-bit Fedora 17.

  
  

• Canon MP560 in Fedora

  Jul 15, 2012

  In order to get my Canon MP560 printer working properly on my Fedora 17 box I had to download the drivers from the Canon Europe website. These drivers should be installed prior to plugging in the printer or you can manually change the drivers in the printer settings.

  Download MP560_rpm_driver_pack.tar from RPM Linux Print Drivers on the Canon Europe website. Extract the tarball and then install the 2 RPMs in the cnijfilter-mp560series-3.20-1-i386-rpm/packages directory. The CUPS driver will now be available (and recommended) as "Canon MP560 series Ver.3.20".