Managed to squeeze DAP42 down to a DIP24 package size. (huge image alert)

[technix]

technix, what is the maturity of DAP42 (your version or the original one)?
Are there any rough edges or does it work OK for the most common things (debug, breakpoints, SWO etc.)?
The Readme files a re bit sparse in details but the original one says:

his project is currently in alpha - features generally do 80% of what's needed, but the last 20% is generally untested.

Sorry to bring the thread back on topic !

Do you have any idea how to debug a CMSIS-DAP firmware? Something must be wrong with my implementation since I am getting RDDI-DAP errors in SWD modes but proper JTAG bus scans in JTAG mode against a STM32F407 target. As of actually programming and debugging that is another can of worms I have yet to open.

[newbrain]

Do you have any idea how to debug a CMSIS-DAP firmware? Something must be wrong with my implementation since I am getting RDDI-DAP errors in SWD modes but proper JTAG bus scans in JTAG mode against a STM32F407 target. As of actually programming and debugging that is another can of worms I have yet to open.

With another debugger?

I have only got my toes wet adding support for Texas MSP432 and NXP Kinetis KE04 (not yet merged) to Black Magic Probe, but all the SWD infrastructure was already in place.

I'm not promising anything, but if I have time I might try to clone your repo and flash it on a Nucleo F042, to see what happens.

[technix]

Do you have any idea how to debug a CMSIS-DAP firmware? Something must be wrong with my implementation since I am getting RDDI-DAP errors in SWD modes but proper JTAG bus scans in JTAG mode against a STM32F407 target. As of actually programming and debugging that is another can of worms I have yet to open.

With another debugger?

I have only got my toes wet adding support for Texas MSP432 and NXP Kinetis KE04 (not yet merged) to Black Magic Probe, but all the SWD infrastructure was already in place.

I'm not promising anything, but if I have time I might try to clone your repo and flash it on a Nucleo F042, to see what happens.

What I mean is finding out the details behind the error message.