VS Electronics and Embedded Development

Per has brought to my attention that the JTAG Wiggler schematic on the “JTAG Wigger Clone” page has an error. I jumbled up the P4/P3 connections on the parallel port when I was adapting the schematic in EAGLE (the schematic is based on this one http://jtag-arm9.sourceforge.net/circuit.txt). I have fixed this error in the JTAG Wiggler schematic image, and I also posted the EAGLE schematic file.

Thanks to Per for bringing up the error.
I apologize for this mistake and I’ll do my best to look out for them in the future.

The other night I came across a 7-segment LED display and decided to interface it to a parallel port. I added a button as well. The 7-segment LED lines (each leg of the display plus the dot LEDs) are connected to the parallel port data pins (D0-D7). I have the button hooked up to nInitialize (bidirectional) and nAck (input only). I’ve never done a parallel port interface project before, so I figured this would be a good start.

I wrote some quick prototype software in Perl, of all languages. It requires Device::ParallelPort for parallel port access, which for some reason didn’t work well with writing data bytes, so I had to resort to doing everything bit by bit in software. For the switch, I bring nInitialize down, and poll nAck for changes. When nAck goes low, the switch has been pressed.

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Yesterday I received the miniLA kit (mini logic analyzer, see more at http://minila.sourceforge.net) from g1powermac.
Some info from a previous post:
“”g1powermac” from the ##microcontrollers IRC channel on Freenode has organized a group PCB and components buy of the “miniLA” mini logic analyzer, freely available at http://minila.sourceforge.net/ . This will be an invaluable tool for FPGAs and CPLDs, which I’m looking to getting into. The device itself has some very impressive features: 32 channels, 100MHz, 128Kb memory for *each* channel, compatible with 3.3v and 5V, and it is of course free. The price will probably end up being under $70 as well. There is also a simple parallel port to USB converter designed for the miniLA, and it looks relatively easy to build.”

Currently there are none available to order, but check periodically because a second run with an improved board is coming along soon.

Here is a picture of it unassembled: