Interconnecting with other things via wires

Forum 2005-2010 (read only) Hardware Development
1

This is probably old hat for many of you, but I haven't been building in quite a while and am just getting back into it again.
I was looking for ways to connect a Mini Pro to 2 CCAs I am making up that will house 3 groups of LEDs, 3 transistors to drive them, a 7805 for +5V, and another transistor to invert a serial stream that uses +5V to represent 0s and 0V to represent 1s (= to RS232 spaces), just the opposite it seems of what that Duemilanove wants to see coming in the Rx pin. (that had me stumped as to why my mask for a certain MSB = to 1 wasn't working for a while -yet the same data thru a serial to USB adapter showed up just fine to the PC).

Am making up 12 boxes with a Mini and 2 CCAs, needing 15 interconnects between them and also to a panel mount connector.
Was looking for a way to make it modular without having to wire up 12 harnesses. Started looking for things like surplus floppy drive ribbon cables (can be had for $0.35, but kind of wieldy at 20 pins x 2
rows).
Then saw 3-pin servo motor cables, that had promise.
Saw in the forum someone had used crimp-on connectors for ribbon cable to make a harness; selection at mouser & digikey didn't look too promising.
Think I finally stumbled across my solution at pololu.com - packs ot terminated wires in different lengths and housings to load them into. If I put male pins on the three boards, and organize the outputs I want a little differently than I had in my prototype sketch, I think I can use two 1x6 headers on the mini, two 1x5 (cheaper than a 1x10 it looks like) on one CCA, and two 1x3 headers on the other, and connect everything up with 15 female-female terminated wires in housings, cutting off a couple of ends to connect to a 9-pin D connector for the panel connector, and only have to solder 4 pins in the whole thing.
These might go together cleaner than I thought!
Pololu P/Ns 1800 for wire, and 1901, 1902, 1904, 1905 for headers.

Gotta see what panel connectors they might have, box will be at the end of a 25' cable with 12V Gnd, and Tx/Tx Rtn going thru it at 4800 baud, so I don't think the harness will be all that critical.

Robert

2

I buy wide multi-colour ribbon cable, then split it as required and add the crimp connectors myself. You get a perfect fit and is cheaper than buying ready-made cables.

Might be a little more work, but the results are great, and I personally enjoy making even the most mundane things - such as cable harnesses! :slight_smile:

G.

3

Where do you get your crimp on connectors? I haven't come across single row connectors, and for less than 10 pins across.
Sometimes its just not knowing the proper name to look things up as.

Also found that the symbol I picked for the socket I have on my CCA are too small for normal male 0.1" pitch headers. Have had to revise the plan to use female headers from pololu - lucked out and had a couple in a shield prototype board that fit the holes, saw what looked like the same thing & called them to check the pin size before ordering.