Finding Arduino Pro Mini footprint


#1

I am starting out on my first real project which is based around an Arduino Pro Mini. I tried ‘Place Component’ and looked for the appropriate symbol in the libraries. In the amtel library there are 10 ATMEGA328 symbols listed none of which appear to represent the Pro Mini which I have represented as


(I would appreciate feedback on whether or not this is an appropriate symbol for same or whether I have transgressed some sacred rule of IC representation. :worried:)

My next step would, I assume. be to create a footprint for this beast, but try as I might I have been unable to find a datasheet giving the applicable dimensions. One could assume that the pins along the sides are at 0.1" centres but there are a few more dimensions which are better read than guessed. Would someone please point me to a usable datasheet or dimension drawing?

Thanks


#2

It’s surprising what you can find with a simple google search like this: “arduino pro mini footprint”. For example this: https://forum.mysensors.org/topic/3509/kicad-arduino-footprint which you can use at least as the base of your own footprint.


#3

Remember that for the BOM and .pos file the module approach will not give you all you would need, as
KiCAD only can do 1 footprint per 1 symbol.
If your module is using more than one physical connector, it needs as many symbols as there are connectors, to populate the BOM and .pos file correctly if those are being populated on the mother- or daughterboard.
If this is just for hobbyist use with manual ordering+population work there is no problem, as you’ll handle this stuff yourself anyway and fill in the ‘data gaps’. But for production you have to keep this in mind and react accordingly - the symbol(s) for the module will have to reflect the physical reality then.


#4

I didn’t find anything at that link which was of any use to me. Lots of talk and very little do.


#5

I’m sorry, Joan, but I don’t understand a word you wrote here. That’s probably because I am a rank beginner at this sort of thing and don’t know the jargon.

BOM is Bill of Materials, what’s .pos? And why would I need more than one footprint for one artifact?

That sentence might as well be in Swahili. My Swahili is worse than my Urdu and my Urdu is awful! :rofl:

I am most certainly a hobbyist, but does my symbol not reflect the physical reality? I guess there must be some functionality in the software which creates a BOM and other stuff from a circuit diagram. (1) I don’t know about that. (2) I don’t think that at my stage I need to know about that. Can we please keep this all simple and suitable for the beginner hobbyist, avoiding oversophistication and overcomplication. I am a bear of very little brain and I get confused easily. :upside_down_face: Thanks

[edit by JTS] sorted out the quote mess :wink:


#6

Hmm, how’s that? The second post was:

“Isn’t that already in the Mysensors kicad libraries?”


#7

That’s more use, but what do I do with the ZIP file? Where do I put it? Do I unzip it? Where do I unzip it to? There is no README in the ZIP.


#8

Completely accidentally, while installing a nightly build, I just found out that the pre-5 version has project templates for Arduinos. I haven’t used templates, maybe someone could help a bit further? Do they work with v4?


#9

What KiCad version you are using?


#10

Every template in the v5 libs should also be in v4 (we did not add new ones in quite some time)

The templates in the v5 repo are however not compatible with v4.


#11

Just copy the kicad_mod file into one of your personal libs. (The .pretty folders)
You can also use the footprint editor to import it into a lib.
More about creating personal libs see: Creating a new footprint library from scratch


#12

I am using version 4.0.7


#13

I don’t have that version at hand, but you can try to create a new project from template (in the main window toolbar and menu). The arduino board is represented a bit differently there, as several different connectors.


#14

I have had difficulty finding accurate, dimensioned sketches for anything in the Arduino world. (And, be careful about using the words “sketch” or “drawing” in that land. When the twenty-somethings who live there begin to comprehend what you’re asking for they are likely to respond with something like, "Oh, you want a picture! Give me a moment to get my phone camera out . . . ".)

You may find some of my old posts helpful:
Arduino Nano PCB Files
Help with importing arduino pro mini . . . .

(Late edit) Here are two more, which include a link to a revealing external page:
Arduino Blank Shield Available?
One aspect of the Footprint Editor is confusing me . . .

Dale


#15

.pos is for pick-and-place machines. It’s irrelevant for hobbyist use.

If you were going to put female headers on your board for the Arduino Pro Mini to plug into, then you need two female headers. That’s two parts for the pick-and-place machine to place. So, you would need two footprints, because each footprint can only specify one part for the pick-and-place machine to place. Again, though, that’s not relevant in the hobbyist case.

The most authoritative source would be the source files, but unfortunately they’re in Eagle format.


#16

There’s a previous topic with dimensions and links to 3D models for the Arduino Pro Mini


#17

I have Eagle so that worked. Thanks.
Arduino-Pro-Mini.pdf (78.0 KB)


#18

Thank you for that. PDF of dimensions in last posting.


#19

Be careful with Pro Minis, especially if you use SparkFun modules (or ones based on sparkfun). They aren’t an exact match to the reference standard, a few of the pins (the four that aren’t near the edge, iirc) aren’t the same.

I know I recently found a KiCad library that had both standard and sparkfun Pro Mini footprints and symbols, but can’t recall where. Might be able to find once back on computer.


#20

I thought it was SparkFun who first developed the Pro Mini, thus defined the “standard”. If you look at the picture of the pro mini on the Arduino web site, the SparkFun flame is clearly evident. The other variants are either someone not following the standard properly, or trying to make it “better” and making a new “standard”… See https://xkcd.com/927/

Also, I found this on the product page for the Pro Mini: “The Arduino Pro Mini was designed and is manufactured by SparkFun Electronics.” So, the advise should be to be careful with Pro Minis if you use one not based on the SparkFun modules. Not everyone follows the reference standard.