For anyone who is reading this... while the method described by @robert-hh works to load the SiPy firmware into the board, it does not perform Sigfox activation which is necessary to connect to the Sigfox network.
If you have this issue, please do the following:
Note the MAC address of your board:
Email firstname.lastname@example.org and include the output of the above commands.
We will respond to your request within 24h on weekdays (often much sooner especially if you write to us during CET working hours).
@brossingo I also had this problem with my Mac. I solved it by going back to the previous version of Atom. You can download it here:
Once you install that version make sure you immediately disable automatic updates (About Atom -> Untick the "automatically download updates" box), otherwise it will automatically update to the faulty version again.
@jez You can use the ustruct module to get a packed byte string. See https://docs.pycom.io/firmwareapi/micropython/ustruct/. If you prefer readable content, you can use one of the two format methods: % operator or str.format(). The result is a str, which you may have to convert to a bytes object with str.encode().
Both is pretty much standard Python.
@andreas said in ADC use to measure battery level / Vin level:
We are getting reasonable readings when using the 1 MΩ / 1 MΩ values as resistor values (matching v3.2)
@MKO just measured the resistor values and confirmed  that it's also 1 MΩ / 1 MΩ for the Pycom Expansion Board v3.1, as supposed.
@brossingo It's unclear if you mean voltage supplied BY the device, or voltage supplied TO the device.
If you're using USB, the voltage is obviously supplied by an external device (PC, power supply...) TO the device, and the device can't change that. If you want to use a different voltage, your probably want to use the battery connector instead, though it depends a lot on what actual voltage you can feed the device and a lot of other considerations.
Could you give more details about what exactly you are trying to achieve?
@brossingo Well, if you're not too versed into electronics, you should probably read up a bit before connecting things. As @Martinnn pointed out, connecting things without paying to much attention can lead to frying up hardware.
Also note that Lithium batteries can be very dangerous. If you handle them incorrectly they can catch fire and/or explode.
Even if you didn't fry the ESP32, the voltage of a LiPo battery exceeds the maximum voltage with attenuation, and completely blows out the maximum voltage without, which explains why you would get the max reading all the time. You need to use a voltage divider and correctly set attenuation.
Note that there is already a voltage divider on the expansion board, you should probably use that. There's been ample discussion on the topic in the forum.