The iBLOPPER/SPINDELMATE can detect the CO2 release by either vibration of the LCD version by inbuild MPU6886, or by adding a moisture protected sound sensor till the G6 pin.
The sound sensor also give the possibility for a longer cord and hence have the M5 ATOM S3 chip outside fridge ion case of connectivity issues.
Where the vibration version needs some isolation towards external vibrations, then the sound sensor is prone to high sounds. If the sound sensor is calibrated correctly this issue is low.
Building a sound sensor?
Both Lite and LCD version also support the use of 3-pin LM393 Sound sensor.
Building the sound sensor is easy, and you just need to add a bit of tape to steady the microphone. Secondly, add a balloon as moisture protection. If you wish to make it very durable you can add some heat-warping for cables (14-16mm radious). I have also added some tin foil to remove any interference, but not sure this really needed.
The LM393 sensor fits nicely in a S-airlock, and should be pressed whole way down. It should still allowe the pressure to get out, but else make a somehow tight “seal”.
The sensitivity of the sound sensor can be adjusted by the small potentiometer on the sensor. In general turn the potentiometer all the way down till no light at all, and then just turn it up until it just lights up when a bubble is hence detected.
The sound sensor version can also be used in a blow-out way, where the s-airlock is turn upside and hence allows any blowout to go to a jar. In this case best-in-class moisture protection should be used.
Up-side-down, blown-out, other airlocks?
