FEZ Domino Mega

I just got my Domino and really like it but it seems a waste to not use most of the I/O capability of the processor. Have you considered Doing a FEZ Domino Mega. Something more like the Arduino Mega? Even if it was not pin compatible stretch the Domino board to expose more of the I/O of the controller. It seems for a few dollars more you could have a dramatically more powerful learning platform. You could leave the existing headers pin compatible with the Arduino to use existing shields but then make the board longer and expose more of the I/0.

If you did that the $99 price would seem a lot more reasonable (at least closer to the Mega but with at lot more power)

USBizi (the core of FEZ) has about 70 IOs but we only exposed few so the pinout is compatible with Arduino. You or anyone with little experience in PCB design can take the FEZ Domino board design (we provide it for free) and modify it to have more IOs.

Now, if all you need is more IOs then there are many ways to get more IOs. Our free ebook explain how this can be done. For example, our 16relay board only need 2 pins to give you 16 relays. It uses I2C. Other way is using shift registers, for example, this board will take 3 pins from FEZ Domino and give you 16 outputs.


We actually just got one yesterday and will be making an example on how it is used…and we may add it (or a better one) to our website.

If anyone is contemplating putting together a customised board with the USBizi as the cornerstone of it, and exposing all the IOs, please let me know. I haven’t got the skills or expertise to take the base design from the Fez and extend it, or to create a design myself, but if someone else was going to do this then I wouldn’t mind piggy-backing on that and i’d be happy to pay for a board.

I took the opportunity of a trip to the US to buy my Fez Domino, and also picked up a USBizi chip, but i have no idea how to build a circuit from the released design - and in fact even the soldering piece might be a challenge, but I’ll tackle that if/when this ever moves to the next step :slight_smile:


Why would you need larger board? More IOs? What are you connecting to the IOs?
Maybe this will give us some ideas on making a larger FEZ!

Yes, more IOs is my desire - see my other post for a few ideas.

I’d like Ethernet, wireless (UART type comms), LCD, a few i2c devices, a few other SPI devices, a few strings of one-wire devices, a few analog inputs (power consumption monitors), a few relay controls, and I’m sure a few other things I’ve forgotten.

In hindsight, the USBizi devboard might have been a better buy for me, with 40+ IOs, but I’d still love to have a board where all the IOs are available (I’m sure it’d be a routing nightmare though :slight_smile: )

and yes I know a lot of the things I outline there are probably easily adapted to use an IO-expander; so I’m not that stressed :slight_smile:

My original idea was to create a board with sockets for some of the standard experimenter stuff. So a socket for Xbee, LCD, built in keypad, socket for Ethernet, and a few sockets for expansion like on the component shield. I can never seem to get the sheilds I want stacked properly. If they were just sockets I could use the ones I want and leave the ones I don’t need for the project unpopulated. I would leave the arduino compatible shield as it is so I could add other shields. I don’t know how hard the layout would be, but I’m thinking of a board like this for my students to experiment with. If I can find someone over in the EE department to help with the board layout I might see if I can find someone to build them.

It should be very easy. You are taking the existing design and just routing more traces. Obviously it is ease for someone that knows eagle. Maybe this can be a comunity effort where we all share in to make a perfect board for everyone. We do not mind helping and even add the board as a standard offer if this help but to that we need to see enough interest plus some serious comunity collaboration

So, who is going to start making the new board :wink:

Oooh, pick me, I’ll start.

I’ve installed Eagle, and I’ve opened the Fez Domino board. I can see both the schematic and the board layout. I’ve even figured out how to switch what layers I can see !

Next!! Whose turn is it now?


I would suggest leaving everything in place whenever possible so the new board is compatible with old one. First, extend the board out from the UEXT side…push it out about 2 inches or more then add more headers. Then, start connecting the USBizi free pins to the headers, there are quite a few of them!

If you look here http://www.ghielectronics.com/downloads/USBizi/FEZ%20boards%20to%20evaluate%20USBizi%20chipsets.pdf
You will see that we used about 30 IOs on FEZ Domino but USBizi has 70 that are directly supported in software so you can add another 40 IOs!!
Not only that, there are another 40 or more IOs that are not directly supported but they can still be used. This USBizi chip is 144 pins so you do the math :wink:

OK, I have to now say I’m in over my head :slight_smile:

Anyone with simple pointers on getting up to speed on Eagle? I have done what I think increases the board dimensions, but I can’t figure out how to place new headers :confused:

I accidentally started another thread on this subject and was redirected here.

The “FEZ Mega” is an obvious next step. While I have used Eagle for simple through hole designs, this one is over my head.
Also even if we have the board, consider soldering a 160 pin surface mount device by hand. Ugh!

I have a friend who is a serious hardware designer as well as an Arduino fan. Perhaps I can coax him into giving a try.

I plan to show off the FEZ at the Boston Arduino Group. Lets see if they like it.


The chip is 144 pin not 160…still not fun to solder :confused:

In one of your responses (7th from initial post) you mentioned:

‘Not only that, there are another 40 or more IOs that are not directly supported but they can still be used.’

Are you referring to the P4 port pins (and others…like some of the P3…those that are ‘N/A’ or blank in the usbizi manual)?
Accessable via GHI specific Register class?

Yes those are the pins I am referring to.

Joe, if you can “coerce” your hardware guy into helping out on the design piece, that would be awesome. A Community driven activity like this would be seriously cool, for the community and I’m sure GHI as well through greater adoption of the USBizi.

I can see a number of hurdles, using the GHI board as a starting point. First, you can’t just take the board and solder it yourself (if you’re an average hardware hacker like me), it’s all SMT and that 144 pin processor looks scary. Second, it’s not the kind of board you can make at home, it’d probably need to be made in quantities to make it cost effectively.

There are companies like http://www.screamingcircuits.com that would solder the boards for you but they will charge you about $100 each!!

We might be able to use something like the open source hardware bank to get a project like this going.


It seems that the folks at liquidware.com sponsor this and must have the ability to help with the manufacturing. I’m in the middle of finals right now, but after this is over I’m going to work on this (a couple of weeks).

Seeed Studio also have a prototyping / open source hardware service, including a kit option, http://www.seeedstudio.com/wiki/index.php?title=Quick_FAQ, and I’ve seen them release assembled OSHW designs/products (Ian Lesnet’s Dangerous Prototype kits, http://dangerousprototypes.com/)

Forgive the naive question. How many layers does the current open source board design use? I only have Eagle freeware which is limited to 2 layers so maybe I’ll be useless in this exercise anyway :frowning:

it is 2 layers…the free version should be able to do everything you need