Jack, Thanks for that example to the group on how com with the USB port will need to be handled differently.
Yes there are going to be a few quirks and software tweaks, but I still don't see any major roadblocks, yet.
It's also a total disappointment that hardware supported I2C SDA/SCL are pinned out differently.
Ron, Thanks for pointing that out.?
Right now, I think that's a mistake on the part of Protoneer.? They may have their reasons, but ???
Thankfully, I2C is pretty easy to bit bang out for com with the SI5351.? We shouldn¡¯t be scared either, someone has already done that for us.
I shouldn't assume anything here, but is seems logical that those who want to add I2C for other peripherals are going to convert?the display first.
If you want a hardware I2C, You can pick up:
SERCOM1 PAD_0? on PA16 = "D11"
SERCOM1 PAD_1 on PA17 = "D13"
You can check my work fromthe SAMD21 datasheet.? I picked my version up from:
https://cdn.sparkfun.com/datasheets/Dev/Arduino/Boards/Atmel-42181-SAM-D21_Datasheet.pdf
The Protoneer board has a 3.3V voltage regulator, so feeding 5V from the Raduino regulator should work fine.
Like Jack said, you can¡¯t drive 5V directly into the I/O pads.?
I haven't built and testing anything.? Just ideas towards a project to serve a lower budget incremental upgrade.
My?Protoneer?board is on the slow boat from ZK land.? Where evidently shipping to the US is much cheaper than the other way.
Regards,
Gary
Ag5TX
