Due pinout diagram

One suggestion for the SPI header. If you print out compiler defined variables MISO, MOSI, and SCK they print out pin numbers as follows: MISO 74, MOSI 75, SCK 76. I believe these are the Digital Pin numbers for these three pins on the SPI header. Variable SS is defined as 10 and that is D10/D77 as you note correctly for SPI-CS0. Could these three Digital Pin values be added? Thanks for your consideration.

Could SCL1, SDA1 be reviewed? Methinks the 9/70 and A.17/A.18 are reversed.

Sorry for my delayed response, I've moved on from this and have other stuff on my mind. I have also completely lost interest in the Due for a couple of reasons.

I have made all the above changes though and will post a new version soon.

@stimmer Negative logic annotated.

@hiduino I don't think I'll add those two LEDs as they are not really part of programming the Due for the normal application. I'm happy to be convinced otherwise though.

@spencoid Hardware pins are now black on light blue, GND still the same. As that's the only use for that combo even if the text blocks out and it just prints black it's obvious what it is I think.

@TheKitty I've added the Arduino pin #s for those three SPI pins, it's a bit of a kludge because there was no room but doesn't look too bad.

@Workalot I think you are right about that, D70 and D71 were correct but the other labels were reversed.

@anyone with a colour printer Let me know if the current colour scheme works, I don't have a printer so can't test. Bear in mind though that all printers are different, if it doesn't look good on a $20 Inkjet I'm not likely to change anything unless a few people have trouble.


quite readable now on my color laser printer. thanks for lightening up the blue. in fact, it looks just like the version i modified in photoshop.

Good, note the errata on the first post as well. I haven't got the energy/time to regenerate the files right now :)


1) This recent activity has made a good document gooder.

2) Your endeavour in time and effort to produce the 'Unofficial Guide' seems out of whack with comments.

3) Noah did, and nr Bundaberg may have somewhat, shared similar water issues.

1) Thanks, but shouldn't that be "more better"?

2) I've currently got the shits with Arduino Inc but I'll get over it. :) Meanwhile I created this document so it behooves me to make it as good as possible.

3) We're up in the hills, apart from the fact that the grass is 5-foot high and it rains every day so we can't cut it the recent events have not affected us thankfully. We just got home in time, Gympie is isolated again today with the highway cut on both sides, we drove through there a couple of days ago. This is Gympie's 4th flood in a year. Poor buggers.


Regarding the two LEDs, I’ve seen several posts of people getting confused about which LEDs they are looking at. So if at all just for identification and clarification so they don’t get confused of what they are, as opposed to the ones used for programming.

OK you talked me into it :), see the first post and advise if the text is not clear/correct.


It looks like the physical pin color was shifted from dark gray to light blue. The LED and SPI physical pin bubbles remain dark gray (no pun intended).

Bugger, I'll fix shortly.


All errata (as far as I know) fixed, new versions uploaded.


Nobody seemed to have asked these questions before, so I'll ask it now: 1. Why do all pins have a "Digital Pin" and "Physical Pin" and "Port Pin" alias? Where are these aliases used to refer to these pins - for instance, when would I need to refer to pin A3 by A.22, or AD4, or D57, or 81? 2. There seem to be many Reset pins. What does the Reset pin in the SPI cluster reset?

Digital pin is the Arduino name and that's what most people would use.

Port pin is for those who are working directly with ports and not the Arduino abstraction layer.

Physical pin is for those who need to actual probe the chip and therefore have to know the real pin.

I don't think there's any programming syntax that uses say "A.22" as such, that's just a common way to indicate bit 22 of port A. Likewise for ADn, but if you are working directly with the ADC hardware you need to know what actual input is being addressed and "AD4" is as good a way as any to do that and the terminology used by Atmel.

Use A3 (for example) for analogRead().

Just the number for digitalRead/Write, ie 57 not D57.

AFAIK all the reset pins go to the same place, it's just that the various connectors use the signal at different times.


Thanks for this - It is really helpful!

Excellent post :). Thanks for this. Very helpfull!

Glad to help.


where did you get the info on the high current vs low current pins? I'd like to map out some other pins from a design i'm working on but i can't figure out whether they are the high current or low current pins. :(

See page 1391: http://www.atmel.com/Images/doc11057.pdf

thanks!! :D