I have always been interested in shoving electronics into mineral oil. How can you not be after seeing the computer (and Pi) aquariums function so well? Ali was on board with the plan but didn’t want to deal with getting large quantities of laxatives to fill a small fish tank. We ended with the idea of mixing water and mineral oil with some flowers. The water sinks to the bottom since it is ‘heavier’ than the mineral oil, so we hope that the plants get water without absorbing too much of the mineral oil and dying immediately. We really didn’t do any leg work to validate this idea but at least we kept a control, right?
I don’t really have any large goal behind this project. I do hope to learn a couple things like, will the wireless still work, how does the CPU and GPU react, will it work after we wash it and now, will the flowers wilt?
Raspberry Pi+Mineral Oil Setup and Configuration
This Model B 256mb Raspberry Pi is running the latest Raspbian and firmware in ‘turbo’ overclock mode. Raspbian is on a Transcend Class 10 8gb card. The wireless adapter was of the $5-6 variety and works pretty well but there has always been some jitter. We hooked up 3 LEDs to the GPIO pins for the lolz (and basic error reporting). The last element is the battery – one of the best things I have purchased for the Pi.
Using the command ‘vcgencmd measure_temp’, we had an average idle temperature of 36.9° Celsius (~98.42 F) in a 20.5° C (~69 F) room before we pushed it to turbo. After turbo the temperature idle temperature was 40.1° Celsius.
We were able to push the temperature to a high of 54.1° Celsius running ‘sysbench’ and playing with the GPIO LEDs.
Post Mineral Oil Dunk
We saw an immediate impact. The idle temperature was 27.7° Celsius (~81.86 F). With the same ‘sysbench’ and GPIO test, we could not get the temperature over 36.9° Celsius.
The wireless still works under the mineral oil! The dongle is only a quarter of an inch under the mineral water but I still expected it to fail. Alison on the other hand, was positive and it turns out correct.
Update 1/10/2013: Carnations are the cockroaches of flowers. Flowers still look good. Pi still function well with the idle temperature between 28-30° Celsius. Wireless has worked great without noticeable interruption. We will lose a couple pings every once in a while but really not bad.