# Installing heat sink on ALIX.3D3

A few days ago, while I was compiling some stuff on my ALIX.3D3, I discovered a very high CPU temperature by chance:

M/B Temp:    +59 C  (low  =    +0 C, high =   +70 C)
CPU Temp:  +71.1 C  (low  =  +0.0 C, high = +70.0 C)   ALARM

Alix.3D3 with heat sink

I downloaded the datasheet of the AMD Geode LX800 CPU to check which temperatures are OK. On page 598 I found that my model (ALXD800EEXJ2VD) is fine for temperatures from 0 °C to 85 °C. Anyway I looked in my spare part box if I could find a suitable heat sink and fortunately I found a 40mm x 40mm x 9mm one. So I ordered some thermal adhesive and installed it.

# Adding additional I²C sensors to ALIX.3D3

J8: SMBus

The manual of the ALIX.3D3 board mentions a lot of pin descriptions of all pin headers on the board. J8 interfaces the SMBus of the AMD CS5536 Geode companion (which is compatible to I²C if bus speed is below 100kHz, see Maxim’s Appnote for detailed comparison). So why not add additional I²C sensors. As an example I connected an LM75 temperature sensor.

First of all we need to add some pin headers to J8 found on board next to the USB port. Continue reading

# Temperature sensor on ALIX.3D3

LM86 on ALIX.3D3

The schematics of the ALIX.3D3 mention a temperature sensors LM86 on page 2 which external sensors pins are connected to the TDP/TDN pins of the Geode LX800 CPU. So this sensor should be able to measure CPU and mainboard temperature.

The LM86 ist connected by the SMBus (which is compatible to I²C if bus speed is below 100kHz, see Maxim's Appnote for detailed comparison) via the AMD CS5536 Geode companion. Continue reading