Raspberry PI With Liquid Flow Meter Connectivity

Hi Gurus,

I am looking to purchase Raspberry PI 3 prototyping kit and 5 of the Liquid Flow Meters for building a prototype,

planning to model this cool concept https://learn.adafruit.com/adafruit-keg-bot?view=all

I would like to know

  • If it would be possible to connect 5 of liquid flow sensors with the Raspberry PI 3 “Raspberry Pi 3 Prototyping Kit SKU:CE00299” if not how many sensors it can handle at a time.

  • Is there any other hardware / items that would be required for me to have this setup ready

  • I believe the “Liquid Flow Meter - Plastic 1/2 NPS Threaded” is a digital one ? need confirmation.

Product links are below:


Hi Pavan,

Sounds like a great project. That flow meter should do the trick, but I’ll draw your attention to a couple of things from the production description:

By counting the pulses from the output of the sensor, you can easily track fluid movement: each pulse is approximately 2.25 milliliters. Note this isn’t a precision sensor, and the pulse rate does vary a bit depending on the flow rate, fluid pressure and sensor orientation. It will need careful calibration if better than 10% precision is required.

The trick here will be reading pulses from 5 different meters for every 2.25 millimeters of movement.

I wouldn’t recommend going with the Raspberry Pi for this, as there isn’t much need to use a single board computer for something that requires only internet access and GPIO capability.

A much better option would be the Particle.io Photon or Electron (just depends if you want Wi-Fi or 3G) as they are real-time microcontrollers with hardware interrupt pins, which means you can super precisely track those pulses from the sensors to keep track of things. You’re also able to integrate your Particle.io account directly with IFTTT which means you can post to twitter easily (without much coding), and nice things like that. Just food for thought.

Best of luck either way :slight_smile:

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