sound_level creates a sample buffer every time

[kevinjwalters]

The code checks if self._sample has been initialised and then assigns a new buffer to self._samples (note plural!). It looks like a typo which wasn't picked up by linting as _sample is used for playing sounds over tiny speaker.

Adafruit_CircuitPython_CLUE/adafruit_clue.py

Lines 815 to 816 in 670355e

	if self._sample is None:
	self._samples = array.array("H", [0] * 160)

This causes a new buffer to be created on each read of the sound_level property. This doesn't leak but it is inefficient and may cause problems for applications with a small amount of (fragmented) remaining memory...

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Once this is fixed, a single read of sound_level may be beneficial at the start of a program that's tight on memory or encountering MemoryError: memory allocation failed, allocating 640 bytes exceptions later when sound_level is used repeatedly. This approach aligns with the advice in Adafruit Learn: Memory-saving tips for CircuitPython: Memory: Reducing fragmentation.

Advanced programmers: Allocate a large memory buffer early in the life of your code and reuse the same memory buffer through your program.

[kevinjwalters]

Same issue elsewhere: https://github.com/adafruit/Adafruit_CircuitPython_CircuitPlayground/blob/511f55ca17a742a5249540d92fa97e66a4226887/adafruit_circuitplayground/bluefruit.py#L90-L91

I've not done a comprehensive survey on this.

[tekktrik]

Looks like this got solved (at least in part) by PR #54, is this fixed now? Or is it worth specifically calling gc.collect() after self._samples = array.array("H", [0] * 160)?

[FoamyGuy]

I do believe this is resolved by #54. I've submitted a similar fix into the circuitplayground repo and I checked the bundle for any other instances of self._samples and found none.