I finally did the version of this that I had envisioned.
https://oshpark.com/shared_projects/Sk27mJwq
The idea here is you just buy a cheap modem cable for $2 and cut off the
9-pin. No dupont crimping, no backshell assembly, least possible strain
from stuff hanging off the 2x4 header in the tpdd. The tpdd-end only
needs heat-shrink and maybe some hot-glue. I think I actually prefer
that to making the pcb any larger to make a dedicated place for
strain-relief.
One thing not in the pics yet is, to get a polarity bump, I'll try
replacing the 2x4 header with a 2x3 standing on two in the middle,
flanked by two 1x2's. Should work fine and be less finnicky than trying
to glue something onto the top of the 2x4.
--
bkw
On 6/1/19 8:47 PM, Fugu ME100 wrote:
I went for a slightly different solution and made a level shifter
board that fits into the TPDD 8x2 plug on one end with a DB25 towards
the Model T, then used an off the shelf straight through serial cable
to connect the TPDD to the Model T. Works really well no need to
crimp anything just all very straightforward soldering :)
Did need to ‘extend’ the board a little to get the connector to fit
properly into the TPDD. I used an edge solder approach as you can see
(Hope the image is OK to attach?) I didn’t bother with a enclosure
the board is really tiny, although thought about using shrink tubing.
It could of been a DB9 but I had a lot of DB25s to use up :)
From: M100 <m100-boun...@lists.bitchin100.com
<mailto:m100-boun...@lists.bitchin100.com>> on behalf of Brian White
<bw.al...@gmail.com <mailto:bw.al...@gmail.com>>
Reply-To: <m...@bitchin100.com <mailto:m...@bitchin100.com>>
Date: Saturday, June 1, 2019 at 5:14 PM
To: <m...@bitchin100.com <mailto:m...@bitchin100.com>>
Subject: Re: [M100] dsub 25 hood that fits
<snip>
Another idea is make a different pcb which goes on the tpdd end
instead of the m100 end. A crimp-on 2x4 idc (he said, redundantly,
given what idc stands for) plug does not fit in the hole in a
tpdd, but maybe a female 2x4 pcb header does. If you could just
extend a female pcb header to stick up off a pcb surface just a
little more, then you could have a small pcb that sits flat
against the back of the tpdd, and has a plug that sticks in to the
tpdd. That would eliminate the *excruciating* process of crimping
individual tiny dupont connector pins I'm using right now. Then
just cut the db9 off a common modem cable and solder that to the
pcb, and you have a full cable that was much easier to build, and
which fits in a M100. (Rick's original cables were easy enough for
him to build only because he used FB100 cables to provide the tpdd
plugs. I'm going for more available parts.) Only remaining problem
there is some sort of enclosure for the pcb. Maybe the 2x4 header
can be a right-angle type, and so the pcb sticks out 90 degrees
from the tpdd in line with the cable. Then, assuming the whole pcb
is small so it doesn't stick out too far, and give it a little
dog-bone shape, you could zip-tie the serial cable to it and
enclose the whole thing in simple heat shrink. I don't know if you
can get a right-angle header to stick out far enough from the side
of a pcb to allow it to reach in to the pins in the tpdd though.
And I don't think there's enough room for the pcb to extend inside
the hole either.
<snip>
