Low cost GDB Jtag debugger hw

[JoeyG]

What can you suggest and where can I get.

Something like a J link etc

Any clones?

[ataradov]

You can't go much cheaper than PiPico and CMSIS-DAP firmware like PicoProbe or my Free-DAP.

[fchk]

For STM32 a STLINKV3-MINIE is cheap and fast, and you get a debug uart as a bonus.

https://www.st.com/en/development-tools/stlink-v3minie.html

[GromBeestje]

As suggested before, some CMSIS-DAP firmware running on a micro. Or alternatively have a look at the Black Magic Probe.
-- If you want it really cheap, all these can run on a BluePill.  (but a dedicated board, costs more, but is more convenient)

[JoeyG]

Could a modified DAP PICKit5  work?
 
See here  https://pypi.org/project/pycmsisdapswitcher/

[newbrain]

Another decent and cheap option is NXP's MCU-Link.

Pros:

• Slightly more expensive, but better built than the ST-LinkV3 MINIE.
• JTAG/SWD
• 1.2 to 5 V targets (ST-LinkV3MINE is 1.65 to 3.6 V)
• Serial port accessible through the usual 2.54 mm pins, rather than the odd BTB 2 mm edge connector on the ST.
• CMSIS-DAP

On the cons side, still micro USB instead of USB-C, and possibly a bit slower.

[amymcneil]

I've been using the 1BitSquared Black Magic Probe which has a built in GDB server that you connect to via a USB serial port. There is a second serial port that is broken out to TTL level RX/TX lines for debugging with the uart on your target.
Details here: https://1bitsquared.com/collections/frontpage/products/black-magic-probe

I've been really happy using it with various STM32 series micros, though it is not STM specific, it will work with most ARM Cortex-M and -A micros. Works a treat with the SWD connection on the STM32, haven't needed to go full JTAG yet.

[AVI-crak]

CH347 It can operate in several modes, including JTAG-SWD. Low startup speed must be enabled in the communication settings, otherwise the ARM chips will malfunction. At high speed, the wires should be no longer than 5 cm; it's best to solder them directly to the board nearby.
Pros: it doesn't heat up like the ST-Link V3 MINIE, it can be used as a programmer (very quickly), the active components measure 20 x 12 mm, and it's sold on AliExpress as an original (no counterfeits).