August 2016 - daangemist Blog

Disable blue blinking light on Odroid C2

Aug 29, 2016 daan

I recently purchases an Odroid C2 unit which I used for hosting some sites. This site, amongst others, runs on it. The unit sits in my livingroom behind the couch. The case is transparent and there was an annoying blue light which blinks ever second. At day time this is not a problem, but during the evening and nights this became a problem. Lucky I found an easy solution on the Odroid forum:

sudo -Hi
echo none >/sys/class/leds/blue\:heartbeat/trigger

By executing these commands on the terminal of the device the blinking will stop. It is removed at reboot however, so you should add the 2nd line to your /etc/rc.local file to have it set at boot time.

Source

Enabling swap on raspberry pi

Aug 11, 2016 daan

Yesterday I was building something from source on my Raspberry Pi B model. It was a text to speech project with some large source files, for the models. Compilation would keep failing because of an out of memory error (which is not surprising, since this model only has 512 MB of memory). Using swap on a raspberry pi is not something you should do normally, but when running into problems like this, I feel it is ok to temporarily enable swap, until compilation is complete.

I decided to grab an old usb stick and use that as the swap partition. You should never use the SD or Flash card of the device itself, since the constant writes will wear it out pretty fast. On stackexchange I found a simple guide to enable swap (raspberrypi.stackexchange):

mkswap /dev/sda
swapon /dev/sda

WARNING: all data will be cleared from the usb drive! This assumes that the usbstick is mapped as device sda after insertion. After you can run the memory-intensive task. Be aware that it will probably very slow, because of the swapping. My build task ran for 1,5 day. When the job is completed, you can run the command below and remove the usb drive.

swapoff /dev/sda