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My second mod, The Lego RCX microcomputer and PC collide!

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Nov 22, 2001
Blacksburg, Virginia, USA
Hey, I'm really excited after finishing this mod. It uses the lego RCX microcomputer to control an internal fan by reading from a temperature sensor that is in the computer or you can controll it from a vb6 program that sits on the background image transparently.
It also light up your keyboard with an overhanging led lamp when the lights turn out.
How it works:

The Fan Controll:
1: a 5v line from the computer powersupply runs into the negative wire of the RCX's motor output A.
2: The RCX can then add voltage to the 5V line depending on: user input from the VB6 program, remote control signal to cycle high, med, low, or it can decide the voltage by itself using the temperature sensor.
3: then the new amount of voltage comes out of the positive wire of motor output A to the fan, then grounds into the comp.

The light:
I placed a small light sensor on the back of the RCX that senses when it get's dark in the room and if it does it shines a litle bit of light on the keyboard. The VB6 program can also turn the light on/off.

The RCX is $150 and running upto 14V through it when it's meant for 9V can easily damage it or the computer if you screw up so DO IT AT UR OWN RISK!

The Diagram:

Here's all the pics:

If you wanna do this I'm a post or PM away.