bc Cal External Temp With Heat Sink

PiRobot Build 2: Adding Heat Sink & Temp Tests Raspberry Pi

I wanted to add heat sinks to keep the core Raspberry Pi temperature down while running cpu intensive processes. I have made some huge strides on the PiRobot project, I just need get may act together and make all the posts. Here is one of the last things I have done but it is going to be an easy blog post so I decided to publish this 1st.

I checked the Raspberry Pi core and external temperatures during 3 stages for both OEM and after the heat sinks were installed. As a control the device had an external temperature reading of 24.7°c off and unplugged. While Idling the OEM average core temperature was 43.29°c with a max of 44.4°c and a min of 42.2°c. The external temperature was just about 40°c.

The 1st load test I did was using Python finding prime numbers. It found 78497 primes in 5:42.61 but the CPU usage never went above 25% so I needed to find another test. After reading how I can use the basic calculator as the CPU benchmark I modified the original equation so that the CPU would be maxed out for at least 20 minutes:

 $time echo "scale=10000; a(3)*8" | bc -l

You may need to install the bc package:

 $sudo apt-get install bc

After 20 minuets of 100% CPU usage the average core temperature was 45.38°c on the OEM Raspberry Pi, it maxed out at 47.1°c.

After installing the heat sinks on the Raspberry Pi the core and external temperatures definitely dropped. After idling for 24 hours the external temperature was 38.5°c and the  core temperature was 39.5°c. After ruining the same bc equation for over 20 minutes (100% CPU usage) the average core temperature was 42.67°c with a miximum temerature of 44.4°c. For more details of temperatures download this: HeatSinkTests.xls.

Raspberry Pi Heat Sink:

raspberry pi

IALEDPants v0.1b: WS2801 + Arduino

Here is the demo of my new WS2801 individually addressable RGB LED pants. The pants are lined with WS2801 RGB LED strips. The strips are controlled by an Arduino and powered by 4 AA batteries. I wanted to create this video quick before I add some additional features. I plan to add a microphone to code them to be noise active as well as add a pot to control the intensity of the LEDs.

WS2801

ws2801