This doesn't work on the current version of Circuit Playground Express due to insufficient memory

[nyponen]

When I tried running this on a new Circuit Playground Express, I got
Traceback (most recent call last):
File "code.py", line 62, in
MemoryError: memory allocation failed, allocating 184 bytes

According to Adafruit customer support, this is "due to the size of CircuitPython + Libs increasing and the M0 Express being strapped for memory". They recommended the Circuit Playground Bluefruit which has significantly more memory. I will test this code when I get the Circuit Playground Bluefruit. Is the code on the Adafruit website current, or are there newer versions of anything I should install?

[nyponen]

I got the Circuit Playground Bluefruit and am about to test it. Is the adafruit_midi library on the adafruit website the best to use for this? Or is there a better one?

[nyponen]

It works on the Circuit Playground Bluefruit with a minor code change. Does anyone have an answer on my adafruit_midi library question? Or has this project been abandoned?

[todbot]

Could you describe what you mean by "this doesn't work"? Which "this"? This repo is a library. I just tried the "examples/midi_simpletest.py" on a CircuitPlayground Express running CircuitPython 9.2.7. and it works as expected.

[nyponen]

It got the MemoryError that I described in the first post when booting the CPX with cpx-expressive-midi-controller.py as documented in
https://learn.adafruit.com/cpx-midi-controller/midi-controller

[todbot]

Ah I see, yes. I can verify that cpx-expressive-midi-controller.py on CircuitPython 9.2.7 does not work due to not enough memory. That was already a pretty complex program to be running on a CircuitPlayground Express, and it just barely fit back in 2019.

You have a few options.

• The first is what you've started doing: using a more capable board like the CircuitPlayground Bluefruit. This is preferred as CircuitPython and its libraries have grown over the years and the SAMD21-based boards like the CPX were already at their limit of being able to do CircuitPython
• Remove the accelerometer features of this program. I just verified the program works with them removed.
• Attempt to run the existing code on CircuitPython v4 or v5. This is challenging because it's hard find a ready-to-go version of CircuitPython with library bundles at a specific version. The bundle releases are archived here: https://github.com/adafruit/Adafruit_CircuitPython_Bundle/releases and the CircuitPython releases are archived here: https://adafruit-circuit-python.s3.amazonaws.com/index.html?prefix=bin/circuitplayground_express/en_US/

btw, this isn't an issue with this library, but rather perhaps should be submitted as a Feedback on the page https://learn.adafruit.com/cpx-midi-controller/midi-controller (along the left side there's a Feedback link)

[dhalbert]

Does it help any to precompile cpx-expressive-midi-controller.py to .mpy?

[todbot]

Does it help any to precompile cpx-expressive-midi-controller.py to .mpy?

Unfortunately, no.

[nyponen]

I sent a request to Adafruit customer support to update the guide to refer to the CPB instead of the CPX. Their reply was, "I will update the guide to CPB only to keep it relevant."