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220 points wonger_ | 2 comments | | HN request time: 0.436s | source
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plasticeagle ◴[] No.42191292[source]
This is cool, but a moving average filter is pretty bad at removing noise - it tends to be longer than it needs to be because its passband is so bad. Try using a IIR filter instead. You don't need to deal with calculating the coefficients correctly because they'll just be empirically determined.

out = last_out * x + input * (1-x)

Where x is between zero and one. Closer to one, the more filtering you'll do. You can cascade these too, to make a higher order filter, which will work even better.

replies(2): >>42191330 #>>42191815 #
1. thefroh ◴[] No.42191330[source]
i've heard good things about using the 1 euro filter for user input related tasks, where you're trying to effectively remove noise, but also keep latency down.

see https://gery.casiez.net/1euro/ with plenty of existing implementations to pick from

replies(1): >>42197815 #
2. plasticeagle ◴[] No.42197815[source]
That sounds very interesting. I've been needing a filter to deal with noisy A/D conversions for pots in an audio project. Noise on a volume control turns into noise on the output, and sounds horrible, but excessive filtering causes unpleasant latency when using the dials.