The Goal

Write a CP module that puts SamD21G18A into sleep mode. Wakes up on interrupt.

What works

From a modified Atmel Start project, waking from interrupt works as expected.

What doesn't work

From the mu editor:

import board
import wakey
wakey.zzz(board.D12)

does not return.

Expected behavior

I assume when the CP code is running wakey.zzz(board.D12) it goes into standby model. Applying a 3.3V level to D12 on the Itsy Bitsy m0 (i.e.: PA19) will bring up the next command prompt (i.e.: if started in REPL) or next source line (if in main.py). Specifically:

• apply 3.3V to D12.
• EIC_Handler is called.
• EIC_Handler calls wakey_interrupt_handler in wakey_helpers.c

Debug effort

• I have been using CP's make: make BOARD=itsybitsy_m0_express DEBUG=1 then loading the .elf file into Ozone. For me, Ozone provided the best of what I liked using GDB CLI and Eclipse without the "hard core" GDB CLI or the "heavy (heavy)" Eclipse configuration. I am so enthused, I made a video to show you what I mean.
• Walked through PulseIn to verify registers for EIC and GPIO were set similar to those I set.