Manual wakeup in additon to card.attn

I am currently in the design phase of a gateway using a notecard plus a carrier (A, maybe F).

I have read about low-power design and I can see in the docs that the F-carrier connects ATTN with F_EN. Are the following assumptions correct:

  • the status of the ATTN automatically enables/disables the Feather. I can use card.attn to set a wakeup time.
  • I can configure an AUX as gpio and use this to additionally trigger the ATTN to go high. I would use this as a second (manual) wakeup mechanism.

So setting AUX as gpio with "mode": "gpio", "usage": "input-pullup" would be enough if I attach a button between AUX and GND?

Additional questions (relevant, if I don’t use the F-carrier):

  • is the ATTN configured as push-pull or as open-drain?
  • if it is HIGH, which voltage level does it have?


Hey @datalogger,

And welcome to the Blues community! This isn’t my area of expertise, but I ran your questions by some people internally and they gave me these notes to pass along:

  • Start by using the card.aux request, and configure AUX1 to be an input with pulldown.
  • When using the card.attn request to sleep, use "mode":"sleep,auxgpio" to make sure that auxgpio is an optional wake-up source
  • The IO voltage level on Carrier-F is 3V3 and ATTN is a P-P output. However, if you meant to ask about the AUX pins, those are 5V tolerant.

Let me know if that helps. If you’re still struggling to get this working I can rope in the right people to help you out.



Perfect, thanks, that was the information I was looking for. I am prototyping on the Carrier-F, but the productive setup will most likely be a Carrier-A board.