I have just published my design for a Universal Regulator Board in the Non-AVR Projects section. The idea behind it was that I was using much the same power supply for the majority of my projects, a 7805 and associated components. I thought it would be a good idea to design a PCB that could be configured to accommodate any of the 78XX devices and also the 78(X)XX devices (i.e. 78L05).

Universal Regulator Board v1.0 Gerblook.org Front

It features a polarity protection diode on the input, an optional power LED fed from the output and a snap-off heatsink support. Having built and tested one I found the snap-off to be a little stronger than I had imagined! However, it’s still functional.

I have already begun designing a new version with capability for more regulation devices. This will be released once fabricated by my favorite PCB fabrication house, www.hackvana.com, and tested but to whet your appetite:

Universal Regulator Board v1.1 Eagle Preview

This new version will be configurable for 78(X)XX, LM1117T and LM317 Variable Voltage regulators.

Another up and coming project is an AVR/Z80 Hybrid board. I’ve been a fan of the original Z80 microprocessor since the 80s when I used to program/hack and generally muck around with Sinclair Spectrums. For a goodly while now, I’ve had an itch to do some Z80 machine code programming just like in ‘The Old Days’ so I designed a board that accommodates a Z80 with 32Kb of SRAM, supervised by an Atmega1284.

Z80-Arduino Hybrid v1.01 Gerblook.org Front

The board includes a power light, an M1 indicator to show the Z80 running, reset switches for both the AVR and Z80 and an 8-bit output port for testing. This is very much a prototype and won’t be published on this site, however, if it proves to be successful, I have plans to double the SRAM and give the board a ‘proper’ expansion port. That design, if successful, will be published along with some sort of basic I/O expansion.

Initially, the AVR will have Z80 binary hard-coded into it so that when the board starts up, the AVR will suspend the Z80 with it’s /WAIT line, load the SRAM with the binary, assert the Z80’s /RESET line, drop the /WAIT and then drop the /RESET releasing the Z80 to run through the code in the SRAM. That’s the plan anyway.

Stay tuned…