|
Software
Hardware
- Car MP3 Player On the cheap.
- Conversion of a $30,000 Indigo2 workstation into a Celeron.
- Bit-Addressable ISA Card (2000): On a whim (took about 3 months to get working) I built an ISA card with bit-addressable I/O pins.
- Initial Concept: The idea started out to be a christmas light controller that would control the lights through a WinAmp plugin. I ordered all the parts, built most of the circuit, and promptly found out that christmas lights cannot be separated from their strands. So, the card sat on the table for the rest of the summer.
- Revised Concept: Once college started again I had the urge to get the card working, and possible use LED's instead of lamps. So I finished the card, and it promptly didn't work. Fortunately the school has several $3000 digital logic analyzers which allowed me to take a look at control signals lasting only a few microseconds. As it turns out, I had wired everything perfectly (minus the wires I had crossed but caught earlier, the problem was that I had decoded the address select lines backward (actually, inverse - the 1's were 0's). Switching how those were written down (and changing the jumpers to match) got the card working. I could read and write bits (turn on a fan via an optoisolator) and reading (pull-up resistor on a jumper block).
- How it Works: The ISA card connects the address and data bus to an 8051 family microcontroller. The CS line on the 8051 is connected to the address lines of the ISA bus through some gates and some jumpers. Thus, the card can recieve configuration bytes as well as data bytes by simply writing to the port that the jumpers correspond to. The system could be altered to allow interrupts, as well.
- Current State: Right now it is waiting for an application, but it may turn into a robot controller, or a home automation something. Regardless, I'm proud of it :)
Other
|
