These boards also used the Atmega 16u2 chip instead of the 32u2 chip. The only real difference this causes is that the autoprint feature had to be disabled as it could not fit in the 16u2's memory. A future run of boards will use the 32u2.
The firmware shipped with this board is also slightly improved. Older versions did not include the following functionalities (see main board page for details):
- Programmatically enter board configuration mode: Send ASCII character SYN (Synchonous Idle, or 0x16) to board from computer
- Issue FIGS from computer (with ITA2↔ASCII translation enabled): Send ASCII character RS (Record Sepatator, or 0x1E) to board from computer
- Issue LTRS from computer (with ITA2↔ASCII translation enabled): Send ASCII character US (Unit Separator, or 0x1F) to board from computer
Note that the above non-printable characters (SYN, RS, and US) were programmed purely with ITA2 ↔ ASCII translation in mind, but I did not think clearly enough to realize that even with ASCII translation disabled, sending the SYN (0x16) character for entering configuration mode conflicts with the ITA2 passthrough for the letter "P". This means that whenever a letter P is passed through to the board for printing with ASCII translation disabled, the board would enter configuration mode. This obviously is a big problem for those leveraging ITA2 in passthrough mode (I typically have been using the ASCII translation functionality and thus missed this when testing the boards). This can be remedied with updated firmware that can be flashed to the board if you know how to do it. That can be downloaded from here <need to add link>. If this kind of thing escapes you, I would be happy to reprogram the board for you and pay for shipping since this was my oversight. Contact me if you're in this pickle.
Gerbers, Eagle Files, BOM