Once you copied the files to your board, eject it and unplug it from your computer. If you're using your Circuit
Playground Express, all you have to do is make sure the switch is to the right. Otherwise, use alligator clips or jumper
wires to connect the chosen pin to ground. Then, plug your board back into your computer.
You will not be able to edit code on your CIRCUITPY drive anymore!
The red LED should blink once a second and you will see a new temperature.txt file on CIRCUITPY.
This file gets updated once per second, but you won't see data come in live. Instead, when you're ready to grab the
data, eject and unplug your board. For CPX, move the switch to the left, otherwise remove the wire connecting the pin
to ground. Now it will be possible for you to write to the filesystem from your computer again, but it will not be logging
data.
We have a more detailed guide on this project available here:
CPU Temperature Logging with
CircuitPython.
(https://adafru.it/zuF)
If you'd like more details, check it out!
boot.py only runs on first boot of the device, not if you re-load the serial console with ctrl+D or if you save a
file. You must EJECT the USB drive, then physically press the reset button!
© Adafruit Industries
https://learn.adafruit.com/adafruit-feather-m4-express-atsamd51
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