Arduino board or shield with JTAG and USB

To avoid having to make yet another board, I’ve been looking for an Arduino board (specifically ATMega32U4, like Leonardo) that actually has a 10 pin JTAG for once. No one seems to cater for that.
I’m using Pro Micro a lot in projects and it’d be nice to proto without having to kynar wire shields with JTAG.
Does anyone know of such a thing?

The closest thing I can find is the Atmel Debug Shield Adapter, which either has a leadtime of 6 months or so, or an exorbitant price and/or massive shipping cost.

I specifically need USB device functionalty combined with JTAG access on-board.

It’d almost be worthwhile designing an Arduino board like Leonardo, but adding a 10 pin JTAg?

The last option seems to be an STK600 which has a hefty price tag to justify one single MCU deploy…

To clarify, I only want to develop bare metal, I have no interest in using the Arduino environment and its potpourri of bugs and horrible code.


Hey @Kris131767 - you might have to resort to esoteric ebay listings / aliexpress dealers to find something like that.

10-pin jtag just simply isn’t implemented in hardware for most on-brand arduino because jtag debugging falls outside the beginner use case.
It seems to be implemented on the Due - presumably because this board caters for pro-users.

For an ATMega32u4 you might have to create that custom board I’m afraid :confused:

Thanks Michael,

Yesh, indeed it seems so.
I guess it kinda makes sense that JTAG isn’t considered “entry/beginner”.
Still, “newbies” quickly become sources of information and advance.
It’s silly on one hand, it’s an addition of a 10 pin IDC, don’t have to use it if not needed.
I really like using the Arduino hardware because it’s so cheap.

The Atmel Debug Shield Adapter pops up a few times on Ebay, but not surprisingly ridiculous prices.

I’d consider going to Due, but the current project is an open source (hardware & code) PLL good perfoirmance Airband receiver with all the bells n whistles and with TFT LCD graphics, but cheap to build, will use a Pro Micro.

I might actually considering laying out a Leonardo, but with JTAG + ICSP… would be fun.


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Hey if you wind up making it and decide to open-source the design, drop a link here so others can benefit too :slight_smile: It’s a pretty niche requirement, but that also means you might be the only person who’s gone the extra mile and done the work.

Sure Michael,

If I go that way, you can count on that.
I kinda quite like Core and what you stand for.