I just bought a pic 32 starter kit, and since I did little reading before I picked up the product I found that it came with no simple way of accessing the pic32's input and output. I know there is a pic32 expansion board but I am feeling a little bit burnt by microchip for even suggesting that I need to get an expansion board for my starter kit... anyways before I start ranting, What options do I have to getting simple access the pins? there is a connector on the bottom of the starter kit, I was wondering if there was a standard cable that would fit into that? I just don't see the need buying a 72 dollar board when a bit of wire should do the trick? anyways I would greatly appreciate any advice that can be given
According to page 48 of the user manual here, it's actually a 120 pin connector. According to the schematic on page 57 (and according to Pingswept) it's a 132 pin connector. Digikey has the 120-pin plug which would be on the expansion board here for $7.22. This is probably a discrepancy between different revs of the datasheet, you should call Microchip on this.
The Eagle part layout is here if you want to make the board. It seems that Adafruit or Sparkfun would want to sell such a board, and, if they don't do so now, this is your opportunity! I'd go with batchPCB for this application.
I've previously made a few conversion boards for stuff like this (yes, 0.5mm pitch can be done!) by placing the connector onto some kapton tape on a piece of perfboard (make the tape just short enough so that you can solder the mounting posts on the end of your connector to the perfboard for a secure mount), and then running 30-gauge jumpers to whatever connector your heart desires. I only needed 28 connections on my biggest job (had to do it twice), but the process is doable. A few words of advice:
- Flux is your friend. Lots and lots of flux! Get a jug of liquid flux (a quart should last you just about forever) and a bottle with a small tip that will dispense it one drop at a time, so that you don't bend the leads of your connector or break previous joints with the tip of your flux pen. Clean excess, dried up, and sticky flux off occasionally with some isopropyl alcohol and blot dry, then reapply clean flux.
- Using two or three colors (depending on the number of rows you're breaking this out to) will make organization much easier.
- A good stereo microscope and fume extractor will make this job a lot more pleasant. Not necessary, but nice to have.
- Be careful to avoid heating the connector pins to much: You'll soften the plastic, which will then stop holding the pins parallel.
- Cut your 30-guage wires to a constant length, and just bunch them with loops of bus wire through holes in the perfboard. Don't do too much until they're secured, which brings me to:
- Secure your delicate connections and wires from shorts and provide strain relief by coating the whole thing with hot glue once you're done. Don't use so much that you can't see which wires go to which pins, or at least determine that from your color coding.
- When connecting to a nice, big post on a nice, big .1" header :), just give the wire a 270 degree bend, pull it reasonably tight (hold the other side!) coat it with flux, and burn the insulation off. Pick any remnants off with tweezers, and then apply more flux and solder. Don't try to strip it and endanger your delicate connections.
So, your process is: Put flux on the wire. Put solder on the wire, trim it if you burned the insulation too far back. Flux the tinned wire and connector. Hold the wire on the connector lead. Tin soldering iron, clean the tip, and apply heat to flow the joint. Repeat x 120.
It would seem that digikey has a breakout board for $33.66. http://search.digikey.com/scripts/DkSearch/dksus.dll?FullDetail&name=876-1000-ND#usewithchildren
The mating connector is a Hirose 132-pin FX10. Digikey sells the mating connector, but I haven't seen a version that attaches to a cable. Sparkfun doesn't have an expansion board that I can find.
Maybe try asking in the Adafruit or Sparkfun forums? It's pretty likely that someone has made a breakout board that will be cheaper than $72.