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Project time! Can we hack a cheap blood pressure monitor and use it as a versatile fluid level meter? And which problems do we have to overcome?

https://youtu.be/h5Z5pAUJxC4

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Fluid (Water) Level Meter from Blood Pressure Monitor Hack

Project time! Can we hack a cheap blood pressure monitor and use it as a versatile fluid level meter? And which problems do we have to overcome? My second channel: https://www.youtube.com/channel/UCQwyP4Yd0-O49e05kMUJgQQ Links: MPS20N0040D Pressure Sensors: https://s.click.aliexpress.com/e/_9Ro4fn Blood Pressure Monitor: https://s.click.aliexpress.com/e/_ANdoYt Expensive Blood Pressure Monitor (My wife's): https://s.click.aliexpress.com/e/_AK9ZUz HX711 Modules: https://s.click.aliexpress.com/e/_AsEmbf IRLZ44N N-Channel FET: https://s.click.aliexpress.com/e/_AVLvod The links above usually are affiliate links that support the channel (no additional cost for you). Supporting Material and Blog Page: http://www.sensorsiot.org Github: https://www.github.com/sensorsiot My Patreon Page: https://www.patreon.com/AndreasSpiess Discord: https://discord.gg/JfgDSa8 If you want to support the channel, please use the links below to start your shopping. No additional charges for you, but I get a commission on your purchases to buy new stuff for the channel My Amazon.com shop: https://www.amazon.com/shop/andreasspiess For Banggood https://bit.ly/2jAQEf4 For AliExpress: http://bit.ly/2B0yTLL For Amazon.de: http://amzn.to/2r0ZCYI For Amazon UK: http://amzn.to/2mxBaJf For ebay.com: http://ebay.to/2DuYXBp https://www.facebook.com/profile.php?id=100013947273409 https://twitter.com/spiessa https://www.instructables.com/member/Andreas%20Spiess/ Please do not try to email me. This communication channel is reserved for my primary job As an Amazon Associate, I earn from qualifying purchases #no#midroll#ads

Comments

Stephan

By the way, there is a differential pressure sensor with I2C: XGZP6897D Bought it at Aliexpress a while ago and finally started playing with it yesterday. Seems to work fine... and of course it’s much less hassle then with the MPX5050DP+ADS1115 combination I built some years ago. And for accuracy, with a solenoid to release the pressure makes it possible to get a zero offset value before or after measurement. This way (and with some effort on the ADC side) I belief it was possible to get down to 1 to 5 mm. Another thing I did was to add a solenoid to disconnect the hose from the sensor so a) there can't creep any humidity from the hose to the sensor and b) the hose can stay pressurized while the sensor is unpressurized in idle state.

AndreasSpiess

Hi Stephan, I always prefer sensors with a built-in digital interface too because it removes problems with leads from the sensor to the ADC... Another viewer used a BME280 and got extremely accurate readings. But it was not as easy to connect to the tube... Regards Andreas