Household electrical wiring (the same which powers lights and appliances) is used to send digital data between X10 devices. This digital data is encoded onto a 120 kHz carrier which is transmitted as bursts during the relatively quiet zero crossings of the 50 or 60 Hz AC alternating current waveform. One bit is transmitted at each zero crossing.
I was wondering if anyone has created any hobbyist X10 to serial/spi/i2c modules or anything of the like. There are tons of commercial dongles that are $10+ for receive or transmit only. However I haven't found anything that lends itself to open source design.
X10 doesn't necessarily need to be the exact protocol used, just anything that functions like it. I am just looking for something that allows basic communication over in-home wiring/power lines.
My buddy has a diesel Chevy truck that has 'old ugly amber lights' in the dash that match no other part of the lighting on the car from the stereo to the push button indicators - the color also does not match the light on his a-pillar boost or egt gauge. We found a brief instruction (text only) on how to do the mod for previous year trucks. We set off and made a reasonable tutorial for this truck. Abstracting the steps we went through - it should work on nearly any car or truck as well.
Some of the pitfalls we ran into were the orientation of the original lamps/bulbs was not uniform. Each lamp/bulb had two of four leads soldered to the gauge cluster, and we found no pattern. We used a simple multimeter to figure out which side was hot and marked them accordingly.
We will be making some other (electronic) mods to this truck later as well. Hopefully things like this interest people on here. If not, I'll stick to the uC and logic projects =)
I've been thinking about re-doing the project with different LEDs to try to get rid of the 'hot spots' of light behind the gauges, but I'm not sure what would work out best. I was thinking even shaving/filing down the rounded tip of the LED to diffuse the light a bit more, but I'm not sure on effect as a whole.
I received my Lattice CPLD Free PCB a few days ago. I had the parts on order from mouser a week or two before. The build went ok for my first time ever using 603 size components. The lattice CPLD IC was a reasonable package size and I have used ICs with higher pincount before. I used the drag soldering method because my solder was of improper size to do individual pins, and drag soldering is just plain easier.
Here are the images - one by itself and the other next to my handy bus pirate:
