08/30/2020 at 23:35 •
At least for the initial version, one limitation on the hardware is going to be that for TPI, PDI and UPDI, the unused pins will not necessarily be quiescent. It's on the user to insure that the NC pins of the programming interface are actually not connected, or that unexpected signals on those pins won't do any harm. They will at least be confined to the target power voltage range, but for example, MOSI will have a copy of the transmit data on it and SCK will have a copy of the clock during PDI.
Also, target power will only be applied while programming takes place. If configured, target power will be applied and after a brief delay (perhaps 10 ms or so) the programming cycle will begin. When it's over, target power will be dropped.
08/30/2020 at 23:30 •
At boot, you get the first project on the disk
<PROJECT> <- Remount, -> Select
You use up and down to scroll through the projects. If you go left, the power for the SD slot is turned off and you get:
Insert SD card -> when ready
Click right and you go back to the beginning.
After picking a project and clicking right, you get
<PROJECT> <- or -> last:NONE
This is telling you you can use the left button to go back to the selection menu, or right to start an operation with this project. last:NONE is telling you that the result of the last operation is undefined.
Click right and the operation begins:
SECTION: FLASH WRITE ***
The bottom row is a progress indicator for each sub-task. In general, you can expect first a chip erase operation, then the fuses are set and verified, then flash and lastly EEPROM.
At the end, you go back to the previous screen, with "last:GOOD" instead of NONE, assuming there were no errors. If there were, it would be "last:BAD"
If there are errors, the error is shown and the screen paused for a second before going back with "last:BAD"