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Topic: Standard pinout/socket for proto Freediuno's (Read 2078 times) previous topic - next topic


I have three different protoboard style Arduino compatibles aimed for use with breadboard and protoboards.

These boards were well designed and aimed at different user needs.

IMO it would be nice if they used a standard wide DIL socket format.  This would allow me to purchase a standard 28 pin or 40 pin socket for use on my perfboard and treat the Arduino clone a replaceable chip.  It would not matter if surface mount components where used.

There would be a need to allow for various supply voltages.  If different pins were used for these various supply voltages, the various manufacturers products could be interchanged.

The problem of sticking a 3.3 volt board in a 5v system would still exist; however: IMO the user would be using all 5v parts or 3.3 volt parts.

I would purchase an ethernet based Freeduino when I had a web interface need, a basic USB Freeduino for simpler projects and no com features for the basic projects all using the same pinout and socket.

It would be simple to upgrade my projects as they developed from basic idea to full web interface.

Any thoughts?


I'm not sure what you mean. Are you talking about a *duino on a wide dip footprint or the 'shields'? There is the nano and the mini that are smaller and fit protoboard spacing.


A breadboard accepts any pin layout that is on a 0.1 inch grid.

There are no standard pin outs or physical size standards for Arduino clones targeted for perfboards or breadboards.

It appears that about half of the Arduino community uses complete Arduino's in their final product/project.

A standard socket would allow different suppliers to create compatible units, thus, I could start out with a bare bones unit and latter replace it with a web-based unit latter on.

IMO it would be useful to use a standard Dual Inline Pin (DIP) IC socket.   The most likely candidates are the 28 pin wide DIP and the 40 pin wide DIP.  These sockets were commonly available; however: most new IC now use TQFN or other surface mount layouts.

Due to the lack of interest in this post, I am assuming the user community is happy with physical incompatibility between nano's, mini's, boarduino's and RBBB product.


While the Nano and the Mini aren't fully pin compatible, we did keep the same pin out at the top end: RX, TX, power, ground, and reset.  That won't allow them to be substituted within a project, but it should allow people to create some accessories which are compatible with both (e.g. a prototyping daughter board).  That might be a place to start if you wanted to work on a standard layout.


Arduino clones seem to fit two basic formats:
  • Original Arduino or
  • Basic Stamp form factor

The connectors to this base unit tends to be:
  • USB or USB connector
  • Serial or serial connector
  • Ethernet (newest trend)
  • ISP programmer connector

The above use commonly accepted formats.

What needs to be standardized is the Arduino clone to external circuitry connection.

Possible candidates are:
  • 28 or 40 pin  wide DIL connector
  • one or more 10 pin ribbon cables
  • USB stick
  • mini USB connectors

The numerous Freeduino's suggest there are limits on the original Arduino format.

Suggestions pleaee.


It is sad that the Arduino team decided not to really discuss the developement of their hardware. The Arduino project is open-source in that you get to see the docs of how things are put together and make some suggestions, not actually have any input into how or what hardware gets created.

It's too bad that the A team rejected the somewhat utopian / anarchist model proposed by Daniel Jolliffe surrounding what gets called an arduino. In my estimation, having an open hardware model may have resulted in more standardized form factors earlier, and maybe fixed some of the clunky things, such as the infamous pin 7-8 gap before it got standardized. On the downside, more discussions and democracy does tend to slow things down, as David Mellis has pointed out.

So ironically, the most popular Arduino standard has an admitted flaw in it that at least a minority of Arduino users is really exercised about. Incidentally, this illustrates perfectly the dual nature of standards, benefitting users while also locking in deficits that will eventually make a new standard necessary.

Perhaps following the more or less secretive A team hardware model, the Freeduino community also seems to be working mainly in isolation, with a few exceptions - I have coordinated somewhat with at two other designers and builders and know of coordination between several others. But the standardization may take a long time. That being said there are wonderful additions to the Freeduino universe, (with not all using the Freeduino label - but that doesn't stop anyone from calling them Freeduinos - unlike the Arduino label) happening daily. 1000 flowers are really blooming.

It's so easy to create Freeduinos that anyone with even a bit of electronics knowledge and an interest in microcontrollers is almost guaranteed to succeed. This is probably going to hinder standardization for some time.

I would like to see some standards proposed in the playground with discussion pages following the proposed standards. I think price and manufacturing standards might also be discussed, opening up some of the not-too-hard-to-guess-at secrecy with which hardware is developed. Who knows, open source hardware might even result from the effort. One model would be to put up some public domain designs that anyone can manufacture and sell. This kind of openness may have been what Daniel Jolliffe had in mind when he proposed Freeduino as kind of unlimited brand open to anyone.

Incidentally, this was also one of my hopes in making the RBBB public domain, although I haven't really said that publicly anywhere. I'll be happy to put up the RBBB that way (especially if someone else builds the pages), having made the design public domain, I can't really control what people do with it anyway.


It is sad that the Arduino team decided not to really discuss the developement of their hardware.

Bah.  Too many cooks never finish the soup.
It would be nice if the various on-grid and mini *duino clones had more compatibility, but I don't think it's really necessary, and there would probably be good reasons to ignore whatever standards were adopted anyway (say, "mini" vs "RBBB")


I think the whole OSH model really denies standards to a certain extent. In designing the Pico one of my interests were to break a standard the Arduino Mini had adhered to that was first established by the BS2. A standard can really get in the way sometimes... look at the .1" pin spacing issue. With that said I still tried to stick to the Tx, Rx, +5v, Gnd, Rst pin order that Paul has somewhere on his BBB. I also bumped the Pico down to 24pins so that it could be used in a standard ic socket although Im not sure myself how practical that is. In the end Baskin Robins style every flavor has a purpose...


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