PC Fan Controller for Athena Power Cases

This repository contains the circuit board and firmware for a fan controller which I designed to replace the splitter which ships with the Athena Power RM-1UC138 rackmount computer case.

Instead of running the bundled 12 V fans at full speed, this controller allows you to install your own PWM fans, and set a fixed speed via a potentiometer, with no involvement from the motherboard.

Parts list

Qty.	Description	Installed at	Product ref.
1	0.1 µF ceramic capacitor	C1	Adafruit 753
1	PC power "Molex" connector	J1	Sparkfun PRT-15700
4	4-pin PC fan header	M1, M2, M3, M4	Molex 47053-1000
1	10 kΩ Potentiometer 0.1" spacing	RV1	Core Electronics CE09096
1	ATtiny85 microcontroller	U1	ATtiny85-20P
1	Optional: DIP-8 socket	U1	TE 1-2199298-2

More info

• Controlling computer fans with a microcontroller - which shows the use of a TL-866II+ to program the ATtiny85.
• Building a 1U quiet NAS - information about the computer build which this project was created for.

Licensing

While you are free to use these files to build this project yourself, you do so at your own risk. No warranty or support is offered.

The code for the ATTINY85 microcontroller is based on "4-Wire-FAN-Arduino" by Marcelo Aquino, which is licensed under the GNU GPL.

The hardware files in this repository are additionally licensed under the Creative Commons Attribution 4.0 International License.