Arduino Shield - field of dreams

i don't like the beautifully tinned and evenly spaced at .010 through-holes which I find on shields where i need to add a bunch of stuff to make the thing work.

I don't doubt that this is a highly controversial topic, but I could much better use holes maybe three to a pad, so i can bring a trace in from somewhere else, and make two connections to it. I see some of the generic shields have good spots to add dips and even smds. My current problem is with a logger shield, adafruit (a work of art), but I have to make really bogus bridges to the data pins and then more bogus bridges to the diodes and ICs i need. If there were even additional holes for each of the Uno's pins it would be easier.

What are you guys who figured this out doing?

Something like this?

Search your favorite supplier for "protoboard" or "perfboard"

I don't know of any shields that have that pattern.

You want it to look nice and professional? Or you want it to be in use permanently? Don't use an arduino. Arduino is a Development Platform. It is used for rapid prototyping, where wires are everywhere and solder bridges are the PCB traces. Once your prototype works, you get a PCB made.

have you tried wire wrap

I'm with you on this. Perfboard without little stripes for you takes much longer to wire up, and is more prone to wiring problems because of the additional mess of wires. Plus - you want to include a DIP package? No problem, just solder the wires onto the bottom of each lead... Whereas with board where there are strips of 3-4 holes, you just put in the DIP part, solder it down, and then put all the wires going to it onto the strip, where you've got holes to stick the wires in, and it's easy to connect multiple parts to each pin.

And you could use perfboard to make your own prototyping shield, except one of the headers is a half-pitch off, so you can't get the holes to line up. I thought I saw a shield with strips a few holes long on each pin, but I don't know where that was - I tend not to use shields in general.

Uh, wirewrap? I didn't know people still did that (all the wirewrap stuff that's ever gone by me is older than I am) :wink: Doesn't wirewrap require long pins, which would block you from plugging the shield onto the arduino?

I got it. I have prototype boards which have the sort of pads shown on the photo above. I'll cut one down to fit in the space available and mount it with the copper side up. this way I can solder on through-hole components and other devices with assurance that they are where i want them on the pads. I will mount it by running 4 leads through both boards and soldering top and bottom. Obviously this won't be as strong mechanically, but I can handle that by other means.

Actually this probably makes more sense for the dedicated shield makers because if they did what I was thinking, probably two thirds of their customers would hate whatever they did.

I'll post a photo of what this looks like when I get it done.

As to not using Arduinos for revenue work, you guys are likely a lot sharper than I am. It takes me several iterations to get something to work at all, then two or three more to get it to work well, be elegant, and stout enough to use. it doesn't make sense to go to board for the two or three of these things which finally find their way into service, but it could make sense to breadboard the whole thing with the atmega chip and just the additional functions actually needed.

Here's what I did:

I'll post this when It's done.

Wouldn't it be more convenient to make a protoboard with male headers on the bottom so you can plug it
into the UNO ? If I were going to make one that's what I would do but I bought a protoshield which is exactly that so I don't have to. (for $7 , why bother making one ?)

PROTOSHIELD

I had a height problem. This thing is going into the little case which ADAfruit, among others, sells and it has to fit under the connectors to the LCD. The case can't hold two stacked shields. Case also has to hold a 9 volt battery. I'll post pictures in a day or two.

Here is what I did:

I still need to tidy up the soldering. I also realized that a serial backboard for the lcd would have been a better idea and have one on order. I've been using these pin connectors for years where I have room and found them reasonably reliable and compact. I thought about using locking Molex or JST connectors but they all take more room.

If any of you sees anything which could be done differently and maybe better, fire away. I cannot be insulted.

john

Looks great ! Nice job !

raschemmel:
Looks great ! Nice job !

Thanks much. When I realized how easy this was, it made more sense to leave the purpose specific shield developers to themselves. no good reason why they should try to guess how to lay out pads to please everyone.

I would say that a few years back I bought a development shield from someone (not Arduino, or the usual suspects) and it had a pattern of two and three hole pads that wouldn't agree with anything I could think of. I think there was a fair amount of agreement in the comments on their site, that no-one else had been able to sort them out either. The current official arduino development shields for both the uno and mega are pretty good.

john

Keep in mind that there is always the option of designing (or purchasing) an extension port for the arduino
that contains all the header pins you need, but in a different connector package , so the arduino would go
inside a box and the expansion port would be a Canon plug or some kind of high quality connector mounted
on the side of the box. The other end of the cable from the connector is just a standard plug in shield used
to tap into the bus but has female headers on it so you can stack another shield on top. You lose nothing in
the way of access to the arduino but you extend it to the outside world. The panel mount connector should be femaile gender and the mate is basically a base PCB shield with rubber feet on the bottom. It provides
all the signals , plus power but is external to the arduino box. This can be useful to interface sensors that you didn't include in your initial build. Other useful things is an extension for the External Power Barreljack
mounted on the case using a male female extension cable. The added panel mount barreljack is connected
via a male plug on the end of the wires connected to the panel mount . The plug plugs into the arduino
barreljack. Now you connect any size battery (or an ac/dc adaptor) you want to the barreljack on the outside of the box that houses the arduino.

Tomorrow, I'll photograph the rest of this. I've found that sending 9 volts out the cable to the sensor box and reducing to 5 and 3.3 with buck regulators there saves two wires in the cable - also reduces voltage drop I'd get if I tried to run 3.3 out and back. The i2c mux saves two more and the single wire signal from the thermocouple amplifiers is just one. So I can do this with 5 conductors and get two honeywell pressure sensor signals and two thermocouple signals. not too shabby. The clock on the datalogger shield uses i2c as well but no address conflict. I suppose when i replace the parallel lcd wiring with serial i could also throw that on the i2c bus.

I don't know yet how violent a ride this thing is going to get going aloft in the engine compartment of a WW1 replica D7, but I guess I'll find out. I usually expect to do three tries on something like this to get something that works, is elegant AND sturdy.

This is the result:

What's in the box(the one with the hoses and thermocouple wires coming out):

NICE ! You should package it with the code and post it in the Exhibition/Gallery with the photos.

Too bad about the LCD serial interface. If I added the board for that on the back of the LCD, it became too thick for me to get the 9 volt battery in, so I stuck with all the wires the parallel interface takes.

If this thing does what I hope, I'll make another one in an aluminum case which is big enough to hold a proper battery case. I would say that Adafruit's plastic case is pretty nice.