Notecarrier F - Notecard not detected

The original thread was resolved out of band, and I forgot to promote the solution back to the forum.

In that case, the 3V3 regulator on the Swan was being manually powered down, which was also pulling down the I2C lines and disabling communication with the Notecard.

It resulted from a difference in the internal wiring of the Notecarrier AF and its replacement, the Notecarrier F.

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Welcome @johnedstone and @baitech, it’s great having you here in the forum!

In both of your situations, you can quickly eliminate the Notecarrier F from the list of suspects, by locating the Feather PWR switch and moving it to the ON position.

If that doesn’t work, may I please request that you open a new issue, so the original issue does not get lost.


Thanks for getting back to me.
I’ve had the Feather PWR switch in both positions, and I’ve powered the feather both from the notecarrier and the feather. In none of these cases was I able to have the feather recognize the notecarrier on the I2C bus. I have moved on, and am now using the Notecarrier A and all is working as expected, i.e. the notecarrier is recognized on the feather’s I2C bus. So, for now, I’m not concerned with the Adafruit RP2040 Feather and the Notecarrier F. I posted here mainly to see if a) anyone has had success, or b) anyone has had the same problem. Thanks again for getting back to me.

After thinking about this my question is “I’d like to have one power source for this project. Should I power the Notecarrier F or the Adafruit feather RP2040? Is this documented anywhere?” Thanks

It has finally occurred to me that I should be powering the Feather through the Notecarrier F. My problem has been that I was attempting to power the Notecarrier F from the Feather. It took me awhile to figure this out - actually, by testing with the Feather and the Notecarrier A to determine how the power works was helpful, along with this post. In particular this quote was very helpful (even though it’s a slightly different topic):

Feb '21

Hey @tamberg, great question! You absolutely can plug USB cables into both the AF and the ESP32 at the same time. I do this all the time during development for exactly the reason you describe: to connect directly to the Notecard over USB serial and push firmware updates to the ESP32. Both devices will draw their power directly from those ports, but both are connected to a common ground, so won’t interfere when simultaneously connected.

As for the JST connectors, we recommend powering your project through the JST port on the Notecarrier-AF and not from the ESP32 or another Feather that includes a LiPo. You’re not at risk of ruining either device by powering through the Feather JST in terms of what we have tested, but since the Notecarrier includes additional power circuitry and reverse polarity protection, you’re better off going through the JST on the Notecarrier itself.