EZ Protoboard News
Copyright © 2001-2002,
Permission granted to use under the terms of the GNU GPL.

04-25-2002

The Volkswagen CD Changer interface work has been moved to its own project web page now: The VWCDPIC. Please check there for updates instead of here.

Not much news regarding EZ Protoboards, now that I've got my Volkswagen interface ported to a PIC16F628 microcontroller. Well, except that I will have my first EZ Protoboard freed from use in the car soon. :-)

Finally got the button push data from the head unit properly decoded, except for the six CD number buttons. I can now detect and discern scan, mix, up, down, seek forward, seek backward, and mode button pushes with 100% accuracy. Credit goes to Andy Wilson for pointing out to me that this data is pulse width encoded, not synchronous serial.

I want to provide a low cost device for people with Volkswagen cars to hook up their own audio devices to the OEM head unit using the 12 pin rectangular CD changer plug. I am porting my code to a PIC microcontroller, which should reduce cost a great deal. However, I still don't have a good source of those strange 12 pin rectangular CD Changer plugs. My closest is this cable from Crutchfield for $20. Does anybody know of a cheaper source of those 12 pin rectangular plugs? Email me!

After sitting around lusting over the Bitscope I mentioned last time, I had one of those forehead slapping "Duh!" moments. The Bitscope only samples 8 bit digital data at a maximum 50MHz. Using the EZ-USB FX's GPIF engine, my EZ Protoboard should be able to sample 8 or 16 bit data at the hardware clock speed (48MHz). There's no reason to buy a Bitscope. With the appropriate firmware and software, the EZ Protoboard should be an almost perfect substitute for the Bitscope's digital sampling oscilloscope capability. Duh!

Time to dust off that second EZ Protoboard.

Well, it's been a long time since I've updated the news page (forgot I even had one!). Wonder if anyone noticed that I updated the EZ Console firmware on Nov 14th to make it compile properly on the new SDCC v2.3.0?

Have not done a whole lot more with the project since the last update to this page and the firmware update. I'm currently using my first EZ Protoboard in my VW New Beetle to provide CD Changer emulation for the PJRC MP3 Player I bought. It works, but unfortunately my recieve data emulation is not perfect. About 90% of the time, user commands from the head unit are recognized by my firmware. The other times I have to push the button again to get it recognized. Useable, but not polished enough for release. If I just had a nice digital capturing oscilloscope like Bitscope, I could probably reverse engineer the button push data stream better to get a 100% recognition rate. However, I don't think I'm willing to spend $400 to do this (could almost buy a PhatNoise instead).

By the way, anybody wanna buy a barely used Volkswagen 6 CD Changer off me? I'm not using mine at all since getting my MP3 player hooked up with my CD Changer Emulator firmware. If you have the rectangular CD changer plug in the trunk of your 1997 or later Volkswagen Golf, Beetle, or Jetta it should work fine. $300 or best offer.

Firmware imperfection aside, I'm still really pleased with my EZ Protoboard. That specific one was my first built and I never quite got around to conformal coating the bugger. The thing flops around loose in the trunk of my car and I'm sure there is plenty of static electricity (I've had the PJRC MP3 player reset itself from static discharges many times), yet that EZ Protoboard with the Cypress EZ USB FX microcontroller remains completely reliable.

My second built EZ Protoboard is currently sitting on my desk gathering dust. I fooled around with trying to get it to do ATA stuff a little over the summer, but kind of lost interest in that project when it didn't take off immediately. I can read the hard disk status, tell the drive to spin down/up, or any other command. But I can't seem to get it to read or write a sector properly.

I bought an Archos Q-Disk ATA USB bridge and have been fairly happy with that. There aren't any Linux drivers for it yet, but oh well. I just leave it hooked up to my brother's Windows machine and then access it over the network using SMB.

Finally finished cleaning up the web page and uploaded it all for you to see! :-) I'm really pleased with this new board. It only took one day to build: etching, drilling, soldering, testing, the whole sheebang. The soldering wasn't very hard, especially when you brush a little flux on the pads and pins before trying to solder. Now if only I had some flux cleaner, I could conformal coat my board.

Almost finished building an actual EZ Protoboard 2.2. I don't have any 82 or 330 Ohm 0603 resistors in stock, so I can't quite finish the construction of the IDE interface. However, everything else is done and it seems to be working quite well! No cold start up problems at all like the old 128 pin EZ Protoboard 1. I didn't do anything differently in the circuitry, so maybe the old board's cold start problem was due to a poor solder connection somewhere. Highly likely given that we had to bend the pins inwards to solder that board and then the pins were spaced so closely together that I couldn't see what I was doing.

Finished the EZ Protoboard revision 2.2. I cut out the 56 pin dual row male header and put a 40 pin ATA interface in its place. Made a few other layout modifications as well. Haven't finished updating the parts list below for the new ATA interface, but will get there eventually. Hopefully I wired everything up correctly... I've been feeling rather icky due to allergies and could have made a mistake somewhere between sneezes. Also, my 128 pin EZ Protoboard 1 seems to have totally kicked the can, so I'm microcontrollerless until I get this new board etched and built. :-(

Finished the EZ Protoboard revision 2.1. This one adds optional auxilary I/O capability and some layout improvements.

Finished the first draft of the new EZ Protoboard. This schematic and board layout should work, but it has not been built and tested yet by myself. Still, I have confidence that it will work fine, since it does very little different from my older 128 pin ez protoboard that I did build once and got working.

This single layer design takes up half the space of a standard 100x160mm PCB, and even then it still has a lot of free space left inside. I plan to add some more circuitry (LEDs, buttons, maybe a latch) in the remaining free space before I build one. I'm putting up what I've got now so people can start studying the new design and maybe catch some errors for me. :-) Besides, I'm pretty tired of working on it right now and it might be a while before I get around to adding the final extras to this board.

Just starting to put together the second generation protoboard. This one will use the CY7C646x3-80NC chip because it is easier to obtain and easier to solder. The 128 pin one was virtually impossible for a hobbiest!