Memory read/write Moderators: adafruit_support_bill, adafruit

[Mike1313]

With my Feather M4 Express I want to read/write an integer number (1 to 10) to (non volatile) memory on the board.
As a beginner and being in a Circuit(Python) learning process, I am struggling with this problem.
Do I have to use a "Bytearray"? Or can I make a small textfile in memory (in the CIRCUITPY directory?), where I can read and write this number?

It's hard to find any simple example....

[dastels]

If you start CircuitPython with the flash drive writable to it you could write/read to/from a file. See https://learn.adafruit.com/circuitpython-essentials/circuitpython-storage for how to do that.

Dave

[jerryn]

you might also be interested in the nvm module taht uses a reserved area of the flash for as an NVM bytearray

Code: Select all | TOGGLE FULL SIZE

Adafruit CircuitPython 5.3.0-rc.0-24-gb351e9b25 on 2020-04-24; Adafruit Feather M4 Express with samd51j19
>>> import microcontroller
>>> microcontroller.nvm[0]
255
>>> microcontroller.nvm[0]=10
>>> microcontroller.nvm[0]
10
>>> len(microcontroller.nvm)
8192
>>>



[Mike1313]

Hi, thank you for your reply, I will look into it.