Flow Sensor for Electric Brewery


Check out this excellent flow sensor project from the Adafruit Forums:

I have a problem. When I look at my brewery I think that if it is working, then it doesn’t have enough features. Certain parts of the brewing process suggest specific liquid flow rates, but without instantaneous feedback, how can anyone ever really judge if they’re doing it right? It seemed that commercial flow meters are complete garbage or are insanely expensive. Luckily, Adafruit had my back with an inexpensive flow sensor.

I slapped a couple quick disconnects on it, and replaced the screws that held it together with 3/4″ #4 brass wood screws to allow it to be mounted to a nice enclosure.

The rest of the parts were maybe $15-20, but I had them sitting around from my other projects. I need to get a 9V battery clip. Soldering wires onto a 9V battery because you’re more excited about getting it working than driving to Radio Shack is surprisingly difficult.

The PCB is custom made from OSH Park and drives the LCD, PWM backlight and contrast, and of course counts the sensor pulses. I went a slightly different way than the example sketch does it, because I found that the resolution at low flow rates was too coarse. I use Timer1 set to 62.5Khz and use the input capture interrupt to store the elapsed ticks between pulses.

The sensor works great, but is quite a bit off spec (450 pulses per liter) at flow rates less than 4 lpm. I calibrated by running hundreds of liters of water through it and creating some calibration points that I can LERP between. Flow rate accuracy now pretty tight, off by a couple percent. Careful calibration can take this sensor down below its minimum spec’ed flow rate, down to about 0.7 lpm, but the pulses-per-liter count at that rate changes dramatically.

Here’s some pictures of the device in action on the brewery, where it just snaps on to the existing pump infrastructure. Using sleep modes between pulses means the current draw is relatively low and the 9V battery should last roughly 30 hours in use….

Read more.



As 2022 starts, let’s take some time to share our goals for CircuitPython in 2022. Just like past years (full summary 2019, 2020, and 2021), we’d like everyone in the CircuitPython community to contribute by posting their thoughts to some public place on the Internet. Here are a few ways to post: a video on YouTub, a post on the CircuitPython forum, a blog post on your site, a series of Tweets, a Gist on GitHub. We want to hear from you. When you post, please add #CircuitPython2022 and email circuitpython2022@adafruit.com to let us know about your post so we can blog it up here.

Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.

Join 32,000+ makers on Adafruit’s Discord channels and be part of the community! http://adafru.it/discord

Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7pm ET! To join, head over to YouTube and check out the show’s live chat – we’ll post the link there.

Join us every Wednesday night at 8pm ET for Ask an Engineer!

Follow Adafruit on Instagram for top secret new products, behinds the scenes and more https://www.instagram.com/adafruit/

CircuitPython – The easiest way to program microcontrollers – CircuitPython.org

Maker Business — Pololu’s account of the chip shortage

Wearables — Make it sticky

Electronics — Your job’s a joke, you’re broke, your semiconductor is DOA

Python for Microcontrollers — Python on Microcontrollers Newsletter: Raspberry Pi Pico turns one and more! #Python #CircuitPython @micropython @ThePSF

Adafruit IoT Monthly — 2021 in Recap!

Microsoft MakeCode — MakeCode Thank You!

EYE on NPI — Maxim’s Himalaya uSLIC Step-Down Power Module #EyeOnNPI @maximintegrated @digikey

New Products – Adafruit Industries – Makers, hackers, artists, designers and engineers! — NEW PRODUCT – ESP32­-S3­-DevKitC-1 – ESP32-S3-WROOM-2 – 32MB Flash 8MB PSRAM

Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at AdafruitDaily.com !

1 Comment

  1. Neat but my only qualm is if the flow sensor is food grade or are you gonna be sucking up all kinda BPA into your beer??

    When I was designing process control equipment, we tried to make most of this type of application non-contact with ultrasonic flow sensors.

Sorry, the comment form is closed at this time.