Re: using a pi 400 to debug a pico

On Sat, 9 Mar 2024 01:26:48 -0000 (UTC), Jasen Betts
<usenet@revmaps.no-ip.org> wrote:

On 2024-01-18, john larkin <jl@650pot.com> wrote:

On Wed, 17 Jan 2024 12:16:29 -0800 (PST), whit3rd <whit3rd@gmail.com>
wrote:
>

On Tuesday, January 16, 2024 at 11:02:40?AM UTC-8, john larkin wrote:
>

This is a first pass at the dev board.   https://www.dropbox.com/scl/fi/709v4pqjhe91jnwqh4wvg/Z566_Sch_2.jpg?rlkey=fjq3a9re53cv5l0zn9ya00akk&raw=1   It would be used in development and production test. Every RP2040-based board would have the small-pitch 20 pin ribbon cable header.

>
Why bother with pins, and ribbon connector insertion force?   Just print
test point pads, a few alignment holes, and make a plug of
spring pins.    It's not like you need this access while the unit is
bolted into its box and racked into a larger system.
>
Do it with two different diameter alignment pins, so it doesn't get
reversed.   A captive  nut to retain it would be useful, too.

>
Too much work!  We can buy the ribbon cables and connectors from
stock.

>
True, you'd have to order from digikey and wait a day to get such a
connector (tag connect)
>
we use the Tag Connect TC2030IDC connector intended for PIC programming to
program our ESP32 boards one end plugs right into the ESP-prog, no
modification is needed.
>
The price seems to have dropped recently, perhaps a patent has
expired, also I'm seeing Chinese clones now.

A 20 pin half-pitch ribbon cable would take, if anything, less board
area, and be less wobbly. And has 20 connections! I could use a 16 pin
ribbon connector, but I have plans for all 20. I want to do more than
just JTAG a CPU.