<![CDATA[Please allow jtag or jtag over usb on next version]]>The current M5Stack module is excellent other than the the fact that it does not support jtag.

This major omission reduces its usability for anything but the most trival applications.

I am sure there is another pin which could be used for the lcd chip select.

Regards

Richard

]]>https://community.m5stack.com/topic/1135/please-allow-jtag-or-jtag-over-usb-on-next-versionRSS for NodeThu, 05 Mar 2026 17:56:21 GMTMon, 15 Jul 2019 20:55:36 GMT60<![CDATA[Reply to Please allow jtag or jtag over usb on next version on Sun, 23 Feb 2020 13:50:33 GMT]]>@thrasher
As always, GPIO 14 is already in use for the display.

“All the pins other then GPIO14 are availiable, however for some reason it was used for LCD CS on the M5Stack rendering JTAG unuseable.”

]]>https://community.m5stack.com/post/7548https://community.m5stack.com/post/7548Sun, 23 Feb 2020 13:50:33 GMT<![CDATA[Reply to Please allow jtag or jtag over usb on next version on Fri, 21 Feb 2020 18:40:19 GMT]]>@sgallou said in Please allow jtag or jtag over usb on next version:

@ajb2k3 But is it possible to debug (put breakpoints, show variables, callstack...) through USB or UART ? How ? Works with VSCode/PlatformIO ?

If your asking about REPL then yes it works with VSCode

]]>https://community.m5stack.com/post/7527https://community.m5stack.com/post/7527Fri, 21 Feb 2020 18:40:19 GMT<![CDATA[Reply to Please allow jtag or jtag over usb on next version on Fri, 21 Feb 2020 17:20:22 GMT]]>@ajb2k3 But is it possible to debug (put breakpoints, show variables, callstack...) through USB or UART ? How ? Works with VSCode/PlatformIO ?

]]>https://community.m5stack.com/post/7526https://community.m5stack.com/post/7526Fri, 21 Feb 2020 17:20:22 GMT<![CDATA[Reply to Please allow jtag or jtag over usb on next version on Thu, 13 Feb 2020 12:54:11 GMT]]>I've spotted this interesting article https://www.cnx-software.com/2020/02/12/esp32-jtag-debugging-microsd-card-socket/

But haven't tried it yet

]]>https://community.m5stack.com/post/7383https://community.m5stack.com/post/7383Thu, 13 Feb 2020 12:54:11 GMT<![CDATA[Reply to Please allow jtag or jtag over usb on next version on Tue, 03 Sep 2019 16:58:48 GMT]]>@ajb2k3 Of course we are talking about two different levels of debugging.

The BBC micro is also for beginners but allows both.

microbit jlink upgrade

]]>https://community.m5stack.com/post/5442https://community.m5stack.com/post/5442Tue, 03 Sep 2019 16:58:48 GMT<![CDATA[Reply to Please allow jtag or jtag over usb on next version on Tue, 03 Sep 2019 15:45:17 GMT]]>@repligon said in Please allow jtag or jtag over usb on next version:

@ajb2k3 Are you saying that m5stack has built-in full-fledged debug server that lets you put breakpoints and examine any variables or are you talking about debugging with printf? Because when I was looking for the infro on the first I couldn't find anything.

REPL Explanation

]]>https://community.m5stack.com/post/5441https://community.m5stack.com/post/5441Tue, 03 Sep 2019 15:45:17 GMT<![CDATA[Reply to Please allow jtag or jtag over usb on next version on Tue, 03 Sep 2019 15:26:42 GMT]]>@ajb2k3 Are you saying that m5stack has built-in full-fledged debug server that lets you put breakpoints and examine any variables or are you talking about debugging with printf? Because when I was looking for the infro on the first I couldn't find anything.

]]>https://community.m5stack.com/post/5440https://community.m5stack.com/post/5440Tue, 03 Sep 2019 15:26:42 GMT<![CDATA[Reply to Please allow jtag or jtag over usb on next version on Tue, 03 Sep 2019 07:28:46 GMT]]>@lukasmaximus
Thanks, I've deleted all my posts, so if you have enough privelegies on this forum you can purge them

]]>https://community.m5stack.com/post/5438https://community.m5stack.com/post/5438Tue, 03 Sep 2019 07:28:46 GMT<![CDATA[Reply to Please allow jtag or jtag over usb on next version on Tue, 03 Sep 2019 07:13:06 GMT]]>@thrasher I struggle to see how your webserver on ap question is in anyway related to jtag. I did already give you quite a lot of pointers to how to make a webserver on the M5Stack AP, please keep that to your other discussion instead of going off topic here.

]]>https://community.m5stack.com/post/5436https://community.m5stack.com/post/5436Tue, 03 Sep 2019 07:13:06 GMT<![CDATA[Reply to Please allow jtag or jtag over usb on next version on Sat, 31 Aug 2019 14:13:33 GMT]]>@thrasher Raw micropython is available as standered as UIFlow is built on it. REPL is also available over USB.
You can also Used VSCode and Xcode on OSX to program the M5Stack.
@lukasmaximus89 made a good video on VScode on youtube.
https://www.youtube.com/watch?v=Y9pOWgsNgKk

]]>https://community.m5stack.com/post/5407https://community.m5stack.com/post/5407Sat, 31 Aug 2019 14:13:33 GMT<![CDATA[Reply to Please allow jtag or jtag over usb on next version on Sat, 31 Aug 2019 13:44:58 GMT]]>@thrasher The M5Stack is aimed at the beginners market and so JTAG is not required, Debug over usb or uart is all we need. JTAG is also a dying standard and getting dropped from alot of hardware. its only certain categories of hardware designers who make use of it now, basically enterprise companies.

]]>https://community.m5stack.com/post/5403https://community.m5stack.com/post/5403Sat, 31 Aug 2019 13:44:58 GMT<![CDATA[Reply to Please allow jtag or jtag over usb on next version on Sat, 31 Aug 2019 12:46:44 GMT]]>@thrasher But don’t you need the LCD display operating while you use JTAG to debug your code?
Some kind of demultiplexer hardware added maybe?

]]>https://community.m5stack.com/post/5401https://community.m5stack.com/post/5401Sat, 31 Aug 2019 12:46:44 GMT<![CDATA[Reply to Please allow jtag or jtag over usb on next version on Sat, 31 Aug 2019 11:38:24 GMT]]>@thrasher said in Please allow jtag or jtag over usb on next version:

As far as I understood from different forums/github, we dont have jtag available because one of the pins is used to work with LCD. This case, it appears to be possible to hardmode m5stack, Im thinking of cutting pcb trace of this pin, add 2 point switch which will either connect it to lcd or work as jtag. With some skill you can even dremel a small hole on the side and put switch there

Now that sounds like a good plan for an enterprise version of the M5Stick.
If you have facebook post this on the Official group and PM Jimmy Lau!

]]>https://community.m5stack.com/post/5397https://community.m5stack.com/post/5397Sat, 31 Aug 2019 11:38:24 GMT<![CDATA[Reply to Please allow jtag or jtag over usb on next version on Fri, 30 Aug 2019 12:27:17 GMT]]>@repligon you can debug over the usb connection or over UART

]]>https://community.m5stack.com/post/5387https://community.m5stack.com/post/5387Fri, 30 Aug 2019 12:27:17 GMT<![CDATA[Reply to Please allow jtag or jtag over usb on next version on Thu, 29 Aug 2019 12:42:46 GMT]]>The lack of debugging is literally the only reason that stops me from buying the stack.

]]>https://community.m5stack.com/post/5368https://community.m5stack.com/post/5368Thu, 29 Aug 2019 12:42:46 GMT<![CDATA[Reply to Please allow jtag or jtag over usb on next version on Fri, 16 Aug 2019 12:34:46 GMT]]>@rleinfellner
Wouldn’t you want the JTAG scan path clear for automated factory testing?

]]>https://community.m5stack.com/post/5189https://community.m5stack.com/post/5189Fri, 16 Aug 2019 12:34:46 GMT<![CDATA[Reply to Please allow jtag or jtag over usb on next version on Fri, 16 Aug 2019 06:25:14 GMT]]>This is a major omission from the M5Stack's capabilities.
No JTAG debugging, what were they thinking?

]]>https://community.m5stack.com/post/5183https://community.m5stack.com/post/5183Fri, 16 Aug 2019 06:25:14 GMT<![CDATA[Reply to Please allow jtag or jtag over usb on next version on Sun, 21 Jul 2019 13:15:08 GMT]]>Agree, vote plus 1 for JTAG.. Sales will definitely increase. M

]]>https://community.m5stack.com/post/4835https://community.m5stack.com/post/4835Sun, 21 Jul 2019 13:15:08 GMT<![CDATA[Reply to Please allow jtag or jtag over usb on next version on Sat, 20 Jul 2019 23:11:14 GMT]]>I find JTAG great for real time debugging with H/W breakpoints and variable watching, its also fast. I think its fine it has the other methods also, however its would be good to have JTAG availiable. Even better would be using a dual channel USB chip which could handle JTAG without the seperate programmer like the WROVER DevKit.

All the pins other then GPIO14 are availiable, however for some reason it was used for LCD CS on the M5Stack rendering JTAG unuseable.

]]>https://community.m5stack.com/post/4834https://community.m5stack.com/post/4834Sat, 20 Jul 2019 23:11:14 GMT<![CDATA[Reply to Please allow jtag or jtag over usb on next version on Tue, 16 Jul 2019 10:43:55 GMT]]>I don’t understand why you would want jtag when you can program OTA, USB and UART

]]>https://community.m5stack.com/post/4812https://community.m5stack.com/post/4812Tue, 16 Jul 2019 10:43:55 GMT