Re: RP400 40-pin connector

On a sunny day (Sun, 11 Aug 2024 11:53:20 -0700) it happened John Larkin
<jjlarkin@highlandtechnology.com> wrote in
<d21ibjdvt6odqium3ado62ob1e7sa6n9hc@4ax.com>:

I want to use an Raspberry Pi 400 (the keyboard thing) as the
dev/debug system for an RP2040 based product.
>
https://www.amazon.com/Raspberry-Computer-Keyboard-Layout-Kabel/dp/B08QCQVWH2
>
It has a 40-pin connector on the back. Various sources say that pins 1
3 and 5 are either GPIO ports 8 9 and 7 or maybe 2 3 and 4.
>
Sometimes the pins are labeled WPI and BCM. Wot's that?
>
https://www.amazon.com/Coolwell-Waveshare-Raspberry-Adapter-Expansion/dp/B08RZCR7S8

Expensive
Just some ideas... things I used with normals Pis :-)
https://www.panteltje.com/pub/rtl_sdr_dump1090_via_FDS132_matrix_display_Raspberry_Pi_driver_IMG_4149.JPG
https://www.panteltje.nl/pub/FDS132_matrix_display_Raspberry_Pi_interface_board_IMG_4129.JPG
https://panteltje.nl/pub/raspberry_pi_interface_to_pic_programmer_IXIMG_1345.JPG

I can fix most mistakes there in software, just by reassigning port
names. But two pins are critical, the SWDIO and SWCLK debug lines out
to a Pi Pico or to the 2040 chip.
>
I suspect that on the Pi 400 pin 18 is GPIO5 = SWDIO and pin 22 is
GPIO6 = SWCLK.
>
Is that right? Does that actually work?

I dunno, have no 400 here.

I also note that some people also connect the UART tx/rx between the
Pi400 and a Pico for debugging. Should I do that too? Does it help
software development?

Debugging via RS232 is a good thing.