I've just uploaded a zip file to the archives, a work in progress KiCAD Schematic for an Arduino shield that supports 3 calculator networking. The shield footprint and schematic are in separate zip files. Put the Arduino shield files in the library path for KiCAD, as well as the files in kicad_diy_libraries, and put the gCnBridge files in a project directory. There's a PDF of the schematic in there as well, although it's mostly the same as the schematic in the Calcnet documentation, apart from the connectors.

I've cross checked with the Sparkfun zigbee shield, and that seems to use D2/D3 on the Arduino, so there's some compatibility there. Wifi seems to be a bit up in the air, the Sparkfun Wifi shield takes up most of the data lines. I haven't looked at the new, offical Arduino shield yet, nor have I looked at the Ethernet shields yet.

I have 3 2.5mm connectors for serial connections to calculators, but I haven't broken out the calipers yet to figure out how many I can add to the end of the board, it may be a couple of more.


KiCAD
http://www.kicad-pcb.org/display/KICAD/KiCad+EDA+Software+Suite

Have you prototyped this to see how well it works yet, rfdave? This looks like great work so far, though; your upload is here:
http://www.cemetech.net/programs/index.php?mode=file&id=768

I've got it breadboarded, but the Libusb isn't cooperating on my xp machine, so I'm a little hung up on that.

Ah, that's unfortunate. Well, assuming I can get some of my current projects cleared off my plate, I will definitely grab the materials to give this a try and see how it goes.

I've finished up the first pass of a PCB layout for a 4 2.5mm connector Arduino shield, based on the Schematics in the gCalc net documentation. Is anyone else interested in a board before I order them?

I am extremely interested. Would you might posting a PNG of your board layout, and perhaps the Gerbers as well if you feel like it?

This should be a direct link

http://keystoneradio.com/wp-content/uploads/2014/02/gCalcNet.png

Looks great! Will you be using OSH Park for the fabrication, or something else? I will almost definitely want at least one of those.

OSHpark for sure. I'm trying to figure out what features to add, as there's a lot of empty board space, which costs the same as traces and feedthroughs

Would you consider adding space for a wireless module of some sort? Maybe pads based on Tari's design? That would mean the enterprising user could use it as an Arduino shield, or as a standalone wireless gCn adapter.

Hmm. There's a bunch of wireless shields for the arduino, so for anything hooked up to an arduino there are already debugged solutions. For something stand-alone, this would be pretty big. I'm not sure that would be a good solution.

Fair enough, it would indeed be a great deal to add. Our design uses a CC430F61xx microcontroller from TI, which combines a wireless transceiver, a lot of helpful support circuitry, and an MSP430 microcontroller in one package, so a bit different from the Arduino-based wireless solutions. I suggested it so people who were so inclined could use the shield as a wired hub, then eventually disconnect it from the Arduino and use it as a standalone wireless adapter once they soldered the necessary components on. As I said, though, it's a great deal to add, even if the space is there.

So took a look at the schematic looks good to me only a few things I see that are worth noting.

1) D1-3 should be combined into a single rgb Led takes less board space and iirc will be cheaper then buying 3 individual colored leds.

2) D4 D5 I am assuming they are status Leds but I am not completely sure. Mind verifying?


After I make those few changes I will start a bom for it.

What else could we add that is not going to increase dev time hardware wise on this board but will increase the amount of use. I'm tempted to say lets stuff it full of more pads for upright connectors. (I have things like the flourish demo in mind here where we have 6 calcs interconnected.)

1 - Good point. I'll take a look at RGB diodes.

2 - It looks like D4 and D5 are activity indicators, as they are hooked up to the TI data lines.

I'll also add an array of 0.1 spaced via's as a prototyping area, as well as via's connected to each Arduino line. I won't get to this until next week, though.

So the schedule slipped a little to the right I just uploaded gerbers to OSHpark for the 1st version. I should have 3 boards in a couple of weeks.


http://imgur.com/f1ytI4R

Dave

awesome! hopefully they work as well as intended!!!

Good choice of fabrication house. I look forward to seeing how the first final product looks, and as geekboy said, I hope everything works as you intend the first time around.

OK, I guess I better close on the BOM and order parts.

http://imgur.com/cONFoG4

Need help with finding a parts list paste a bom and i can build it on digikey for you.

Thanks for sending along two of the prototype, rfdave! I must say that it worked perfectly from the get-go, with the exception of a green LED that I had to carefully reverse. We'll be using the shield this weekend at Maker Faire to connect two calculators to globalCALCnet: