What is the MightyBoard 1280 IO used for?


While I've worked on fixing my voltage regulator on my MightyBoard, I've noticed an extra set of pins available labeled Atmega 1280 IO. I've tried finding documentation on what these pin can be used for to no avail. I'm curious if there is any use for them within the scope of MakerBot's Conveyor service or even what sort of functionality with regard to the board itself.

Any links to documentation on this subject would be greatly appreciated.


Posted 2016-02-19T05:42:02.453

Reputation: 6 144

Do you mean 8U2 IO? There's also 1280 ICSP and 8U2 ICSP. Those are the only non-obvious pin headers on the Mightyboard RevE .brd file. – Ryan Carlyle – 2016-02-19T05:50:34.727

Or do you mean the big "ATMEGA 1280 IO" section? That's just a bunch of breakout points for diagnostics like all the debug LEDs. – Ryan Carlyle – 2016-02-19T05:55:41.227



If you check the Mightyboard RevE files on Thingiverse (http://www.thingiverse.com/thing:16058/#files) you will find the schematics and PCB files (.sch and .brd) for the version of the board used in Replicator 1s and (with some minor mods) most clones. The Atmega 1280 IO header section is a bunch of breakout pins for debug functions. There are eight sets of signal/5v/gnd groupings. Four of them are currently driving debug LEDs that show flash codes for particular firmware failure modes. The other four are unused as far as I'm aware.

The ninth and tenth pins shown in the schematic are located on the opposite end of the board, near the 8U2 chip, to give some hacking access to that chip as well. (The 8U2 handles USB comms and firmware flashing the Atmega 1280.)

Schematic excerpt

If desired, you can build your own firmware using these pins for other purposes, such as signaling to external equipment. But building Sailfish is a little more difficult than just running the latest Arduino IDE (for compiler stability reasons) so the vast majority of Mightyboard users never bother modifying their firmware.

Ryan Carlyle

Posted 2016-02-19T05:42:02.453

Reputation: 6 346

I came across the Thingiverse page once and was intrigued with the wording "hacking". I found this very vague. Does this mean you have access to an extra serial IO, way to upload firmware, just more LED " hacks", or something else? I'll double check their Git Hub, as they might have something written in their documentation for Conveyor. Thanks for the info. – tbm0115 – 2016-02-19T13:56:08.023

I think they're all GPIO pins and thus could be used for most anything you're willing to program except some of the special comms stuff, I think. (There are extra UART and I2C headers for that.) You'd need to cross-reference with the 1280 datasheet to see what kind of pins they are. – Ryan Carlyle – 2016-02-19T16:11:39.467

Conveyor talks via a pretty dumb USB link to the 8U2, and the 8U2 has a serial link to the Atmega 1280, so I think you'd need to go through the 8U2 chip. But it's possible the extra UART header could be used, I know Jake Borden did some work on that for ethernet control: http://www.extrud3d.com/alt_uart

– Ryan Carlyle – 2016-02-19T16:14:04.760