FEZ Panda II Screw Terminal Breakout Shield available soon

NETMF & Gadgeteer
1

I recently purchase this shield:
http://iteadstudio.com/store/index.php?main_page=product_info&cPath=18&products_id=475&zenid=dkc0ff0714daibm3c640budra2
and loved it. HOWEVER, my Panda II has 40 more pins that this, and other similar shields, neglect.

I have created two designs to break out all of the Panda II pins to screw terminals. One is developed in Eagle Freemium, restricting it to a 100mm x 80mm. I managed to squeeze enough screw terminals around and on the board for all the pins; 12 terminals are in-board, the rest are on the board perimeter. The other was developed in Pad2Pad and measures approximately 4x7 inches. In addition to screw terminals for every Panda pin, it has provisions for a reset switch and a CR2032 battery, as well as sporting a 378 hole breadboard area with two each 3.3V, 5V, and Ground rails. Both boards have a jumper for grounding MODE for debugging via serial.

Prototype PCB production is relatively cheap ($30-$45/board), but I can get 3 boards for about the price of one, depending on where I go. Does anyone have any interest in such a board? I would happily give a board to anyone willing to split the cost. Let me know here if you are interested, and which board you are interested in.

2

Hi and welcome to the forum.

I think it will help if you post some pics of your shield.

1 Like
3

great option - screw terminals are always good (but take a lot of space, eh!). As Eric says, show some images of your boards and I suspect you’ll get some takers. A panda II is one of the boards I only have a one-off, so it’s not for me sorry.

4

I would like to see what it looks like as well. Welcome to the club!

5

Unfortunately, it is just a design at the moment, has not yet been produced. Here is a “natural” view out of Pad2Pad of the larger board. Any suggestions are welcome!

6

Here is a slightly better picture, with the power traces widened and copper fill ground plane everywhere possible.

7

Looks good! What do you use to design that board? (I have only used Eagle)

8

I used Pad2Pad. Having a heck of a time converting from Pad2Pad to Gerber, however, and Pad2Pad is a proprietary format. The board is 6.4 x 3.8 inches. I can’t afford a version of Eagle that will do a board that big. Eagle seems a bit more difficult to use, but I assume it’s capabilities justify it. Here is an image export from Eagle of the “small” board. Notice the row of screw terminals on the left and two rows on the right, neither of which I consider good features. I tried to add a little more utility to the 5V, 3V3, and GRD terminals on the right to make up for the inconvenient placement. The board needs a little work, some traces are still a bit too close to each other for some manufactures “protoboard” specs.

9

If you have to run dual-run screw terminals, then I would suggest putting them facing opposite ways is a help; just so the ingress / egress points are opposed. A wire coming in from the inner portion of the board for the inner run of terminals is better (imo) than having to come in over the top of the outside terminal block and it’s cables.

Edit: of course, you could just ditch all the “spare” 3v3/5v/gnd connectors, sometimes they can really add to the space. But then again, having 40+ GNDs from say sensors isn’t going to easily fit in one connector too easily either :slight_smile:

10

Ok, not a bad suggestion. Here is an image with the terminals turned around. Not much visual difference, but functionally…