ABOUT DAMN TIME, is all I can say! (and that would be all caps, if this infernal site didn’t make all my first-person pronouns improper along with slaughtering my grammar!)

Seriously, good job, guys! I’ve tossed this idea around for a while and never got into it enough to implement it. Now, can it be expanded to ports that have extra unrelated pins? How much extra time would that add to the detection process?

Posted at 12:00 pm on Sep 29th, 2007 by Myself

Nice. Why not just program the AVR to function as a JTAG programmer over USB once it has found the pins?

Posted at 2:35 pm on Sep 29th, 2007 by tom61

Is it just me, or is the schematics link wrong?

Posted at 6:57 pm on Sep 29th, 2007 by TheShagg

This is a great project, but I’m not sure about the choice of microcontroller. It’s clear that AT90USB would be better suited since it has a USB controller built in, no USBSerial gateway needed. Even the Cypress EZ-USB/FX2 would have been a good choice, and it has been around for a while. Both chips would achieve the future USB goal, and should perform much better since they can be clocked higher (16 MIPS for the AT90USB, 4 MIPS for the EZ-USB/FX2).

As for easy, right-now implementations, perhaps SparkFun’s USB Bit Wacker board would suffice. It’s a PIC 18F2455/18F2550 on a board for $25 assembled, $20 kit. Add in some glue and you’re set. There’s not enough pins for 30 wires at a time, but that can be fixed with a few extra ICs.

Anyway, great project. I’d love to hear success stories using this software.

Posted at 7:15 pm on Sep 29th, 2007 by pc486

This is an idea that should of been up this way before and it’s an idea that deserves a microcontroller. Actually as we’ve seen a few variations of the ultra low budget logic recorders… seeing a few variations of a JTAG pinout detector would be a cool thing.

I wonder who can develop the most functional detector that’s the easiest to build!

Posted at 5:08 am on Sep 30th, 2007 by Bhima

This is awesome!

Funny enough, I was just looking for a JTAG pin detection method 1 day before this got posted.

I personally like the PIC18L2550 (it has a USB interface built-in). I may try implementing this just for fun.

Posted at 2:27 pm on Sep 30th, 2007 by alex

Yeah that is awesome !

This: http://nsa.unaligned.org/jrev.php deserves mention as well ;)

Posted at 2:42 am on Oct 1st, 2007 by phpCypher

When I can’t find the appropriate datasheets, I just find the most obvious 4 pins/pads, check out the impedance and do automatic checking of the 3 inputs. With just a parallel port.
Of course it becomes less obvious when dealing with more than 4 available pins/pads.

Posted at 5:42 pm on Oct 1st, 2007 by DarkFader

Someone should make an idiot-proof howto for this. I know virtually nothing about EEE, but I’d still like to be able to fiddle with the jtag port on my 2Wire 2700HGV router and some other hardware too :( I can’t figure out how to do it manually with a multimeter/oscilloscope :(

Posted at 9:01 pm on Oct 1st, 2007 by Kris

There are no schematics anywhere on that site?? How do you built it?

Posted at 9:12 am on Oct 15th, 2007 by kocoman