Sunday, August 31, 2014

configuring the Yun wifi access

To change/select which WLAN access point the Yun should use you can just edit the following file:

     /etc/config/wireless

Just change the SSID and key.

Getting the status of the wifi:

      iwconfig wlan0

Sunday, August 24, 2014

Reset or reboot not working

I had an issue that when typing reboot, or pressing the reset button, the Yun (open wrt) would not correctly reboot (e.g. the white LED did no go on anymore). The only way the reboot worked correctly was by power cycling the device. Also a watchdog based reboot didnt work.

Cause: my running sketch was sending stuff to the Console. This will interrupt the boot. The "old" Uboot version will be interrupted by any char. A bridge operation will cause the same problem (I think even a get as this is implemented as transfer)

Solution:
 - newer uboot version (with openwrt-yun 1.3) is more strict and will only interrupt on the characters "ard". The upgrade is unfortunatley a manual step that will void warranty. See http://arduino.cc/en/Tutorial/YunUBootReflash  (you can do only the uboot stuff)

extra info: takes about 4sec to enter uboot (so probably a good idea to let a sketch do nothing the 4 first seconds)

Saturday, August 2, 2014

Python - fix indent on existing files

To fix indentation on existing python code on Ubuntu:
sudo apt-get install python-examples
Then to fix all files in the current directory:
/usr/share/doc/python2.7/examples/Tools/scripts/reindent.py .