Here’s a little board I used for a while with a JeeNode:
It has 6 female header underneath, which get plugged into a JeeNode with its header pins sticking upwards. It has an LDR, a diode I tried to use as voltage reference, a plugged-in SHT11 temperature / humidity sensor, a 3-pin connector to plug in a Parallax PIR sensor, and a 2-pin header (top right, behind the SHT11) which was used to connect a couple of 1-wire temperature sensors).
There are a couple of issues with this, though some are probably unavoidable for such one-off / ad-hoc solutions. For one: it’s a bit of a mess. One reason is that with this setup the 1-sided perf-board I used has to be mounted upside down to allow soldering in the female headers. That’s awkward, because it means you have to “surface mount” most components.
One option is to use perf-boards with plated-through holes. These are several times more expensive than single-sided boards, though. But more importantly, cheap one-sided boards are often based on “Pertinax” (SRBP) which is a lot easier to handle than FR-4 epoxy: you can simply break them on a sharp edge, with the row of holes acting as perforation.
The other problem with putting everything on a single board is reduced flexibility. In this case I had to add a second 4-pin female header on top to accommodate the SHT11 plug I had already made – which would have fitted just as well directly on the JeeNode.
One nice benefit of per-port prototyping is that it is easy to re-use this stuff in different configurations. In fact, as with the SHT11 plug showing in the picture, that’s precisely what happened.
So I’ve been thinking a bit about ways to use JeeNodes for experimentation. Which happens a lot around here. One simplifying convention is to always use male headers on the JeeNode. That leaves essentially two choices (ignoring sideways mounting for now):
I’m thinking of having a bunch of, ehm, “JeePlugs” made: tiny boards with a 6×8 “prototype” area containing plated-through holes, plus a 6-pin female header and connecting pads. Three ways to use these:
You’ll need male headers for use with a breadboard, but I’m assuming you’ve used the breadboard to figure out the connections with the bare parts, so this post focuses on using female headers for the JeePlugs.
In all cases, the orientation of the pins is the same, so once you have a plug set up with stuff on it, you could still use it in multiple ways. And plug them onto any of the 4 ports at will, of course.
One last refinement is to make these plugs around 20 x 25 mm – i.e. long enough to optionally plug onto two ports in that inverted 3rd example shown above. Here’s a first design:
It’s really not much more than a tiny perf-board of the proper size for JeeNodes with a couple of doubled-up connections. Using plated-through holes so components and wires can easily be soldered from either side.
The plugs are not labeled with pin numbers or signal names, because those depend on the orientation in which you use them. For that, use the markings on the JeeNode itself (starting with v3, that is).
These JeePlugs only makes sense in larger quantities, so I haven’t yet decided whether I really want to order them. I sure could use some, but it wouldn’t be practical to have less than a hundred or so of them produced.
