First use of Multi-Purpose PCB (UV timer) - Part 1

This was to be a timer system for UV exposures of DIY PCBs. I have already made up and used the UV board, but it was a bit messy to use (pull the power to turn off).

The idea was to have a button for start/stop, and a rotary encoder for adjusting exposure time. Sadly, the encoder was DOA, so I will order a new one. In the mean time I've coded the display, and found out that the atmega8 doesn't have a PC7 (forgot about that), I had wired it to ground on the PCB. This meant I had to some pair wire instead of the 10-pin header.

The FET works brilliantly, and you can see the UV board hooked up, but not on at the moment. When on, the FET doesn't even get hot to the touch, so no need for a cooling rib.

So before I get a new rotary encoder, all that is left to do is to wire up a start/stop button (reset button is already in place).

New PCB service

Made up a sort of prototype PCB in CADStar and sent it away to a new manufacturer I'm trying out. I'm pleased with the quality, two layer eletrical, solderstop, two sided silk screen, and very cheap. Just two minor errors on the PCB on my part: I used 6mm switches instead of 3mm, and there's possibly one air wire, but that could be an auto-router glitch. In the image below, I've mounted the microcontroller, ISP, and a header for unregulated power. This was to test the microcontroller, which worked like a charm.



The board is based around an ATMEGA8, and has most of the standard parts is use: regulator, a few switches, a FET, rotary encoder, USART, I2C, and ISP of course. In addition, all IO ports are fully connected to 2x5 STK500/STK600 type headers with power: Any additional circuitry I can take from the pin headers.

Gerbers, schematics and PCB-file available on request.

Happy hacking!

Combined Accelerometer & Gyroscope

This is from my Master thesis, where I'm building and attitude refference system (ARS) for pitch/roll/heave and vibration compensation for echo location systems.

I've buildt two kinds of accelerometer sensor boards already, based on Freescale and ST-microelectronics chips. The latest addition is the gyroscope board, based on a chip from Invensense. And here they are, finally merged (with the Freescale accelerometer board).



I'll be using Labview and Matlab to implement my ARS algorithm now.

Later I will build a power and interface board, and of course the micro-controller board, making the final system a four stack fully modular design.

Happy Hacking!