Power Supply
Everyone is familiar with the problem of needing a simple 5v or 3v3 power source on hand, but instead using AA's or a wall wart. Batteries are much more expensive compared to power from an outlet via wall wart, but a wall wart itself does not always have adequate voltage regulation, the voltage you want, or the current capabilities. Not to mention that it looks extremely unprofessional to have your bread board project powered with a wall wart and its associated wires shoved into the bread board.
My intention with this project is to design and built a power supply that is fully open source, very reliable and powerful, and “future proof” with an expansion bus for future peripherals, and lastly, be a huge learning experience for myself. The chassis is a 2U server rack, inside an MOT (Microwave Oven Transformer) will provide about 2 kV at high currents, and a good bit of monitoring and control logic. A propeller MCU will provide video output for the system, with a 60 MSPS ADC paired with an FPGA and SRAM used for high speed current and voltage measurement.
PCB printer
After standing around waiting for your water to boil (Tea ftw), you get yet another brilliant idea. How about putting a PIC in there with a relay and a small led and photo resistor to sense when you walk by to automatically start boiling the water instead of pressing the switch. Or even add in a WiFi module so you can collect the data and graph it out, spotting interesting correlations. Ah, but now you need to make a board, and wait weeks for it to get back to you, with your enthusiasm probably draining day by day.
I would just etch the board myself at home, but my ink-jet is abysmal at transparencies, and a laser printer seems too far out of my budget, so what do I do? I design a printer myself, inspired by the 3d printers out there, to use a wax directly on copper technique. My goal is to use parts I have on hand to build this, such as a floppy drive for the Y axis, scanner for the X axis, and a printer for the Z axis.
Rover
I want to make a robot! What do I use? I do not want it to be this little tiny car driving around in my living room, but I also do not want it to be this massive behemoth with an often used kill switch. I don't want to design the chassis all from scratch, that would take up far too much time and cost quite a bit. Why not just make it from stuff I have lying around? I could use a wireless land line phone for communication, the batteries from a ups I found near Columbia University are pretty hefty, and I have a toy RC car lying around.
The goal of this is to design a small rover that is capable of reasonable torque, use one of the 22 Wh lead acid batteries I have, and see how eficient I can make a motor driver. The first step is to use a PIC32 with the motor driver to get the rover moving, with the second step being controlling it with the wireless land line phone. The reason I want to use a land line phone is because they are very easy to find and cheap, which means they are very accessible to nearly every hobbyist, and offering an alternative to the much more expensive Xbee.
Xray has always been a subject of interest to me, the idea to be able and see through objects, especially with magnification is an indispensable tool to any hobbyist. You can use it to see inside chips and see the wire bonds, or even the chips under "black blobs" that you sometimes see on PCBs, not to mention being very useful for BGA and PCB inspection.
One day, as I was walking to get myself some food a few blocks away, I spotted this bad boy just sitting on the curb. After dragging it back (it was very heavy), I started to look a bit closer and see just what I found. There was another machine on the Xray unit, but after a few minutes googling the model numbers, it turns out that it is a simple hearing tester. I will save that for another teardown which I will do when I get more time.