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. :-)
03-31-2002
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!
12-29-2001
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.
12-07-2001
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.
03-29-2001
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.
03-20-2001
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.
03-16-2001
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. :-(
03-03-2001
Finished the EZ Protoboard revision 2.1. This one adds
optional auxilary I/O capability and some layout improvements.
02-25-2001
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.
02-21-2001
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!