Bubbleometer
Hardware
fermentation monitoring
SHOW HN2017
27points
13comments
#1,085of 2,242 in 2017
Top 49%of 2017 by points
How HN took it
CuriousMostly questions and neutral comments
1 positive, 3 neutral or asking, 0 mixed, 2 critical, out of 6 comments about the project. Thread score -0.12.
Execution: 0 for, 1 againstIdea: 0 for, 1 againstPerformance: 1 for, 0 against
The thread, comment by comment
Each row is a top-level comment and its replies, in HN's order. Select a cell to open that comment on HN.
positive neutral or mixed critical about another commenter or something else the maker
What HN said
What people liked
Commenters liked the approach and offered signal processing ideas
From 2 comments
Sampling at 48kHz seems like overkill. If you record at a lower sample rate (e.g. 22k) you will still be able to detect the bubbles, but the files will be about 4 times smaller,…
supernes on HNSince bubbles popping are a random and impulsive source, the spectrum of the detected noise will be the resonance of the glass plus a white noise floor. 48khz is not overkill.…
cocoablazing on HN
Objections
48kHz sample rate may be more than needed
From 1 comment
Sampling at 48kHz seems like overkill. If you record at a lower sample rate (e.g. 22k) you will still be able to detect the bubbles, but the files will be about 4 times smaller,…
supernes on HN
FFT smears the signal in time; squaring the signal may work better
From 1 comment
You are better off squaring the signal. Applying an FFT to get the magnitude will smear your signal in time. I suggest you look into acoustic emission detection.
cocoablazing on HN
Questions
Which correlation function to use for spectral matching
From 1 comment
Yeah I agree with respect to the sample rate. I wasn't really sure what sample rate would be best when I started recording the audio, so just picked the highest the soundcard…
anfractuosity on HN
Alternatives named
CO2 gas sensor (MQ-135) near the airlock to detect bubbles
From 2 comments
Awesome! I attempted the same approach, but after discovering a cheap gas concentration sensor (MQ-135, tunable to CO2) I abandoned the audio approach for a minimum of data…
roevhat on HNI put it near the airlock and detect peaks. For now, the most valuable information I extract is when the fermentation starts and stops -- with notifications on my phone :-)
roevhat on HN
Plaato fermentation monitor
From 1 comment
https://www.plaato.io
devopsproject on HN