From the mail bag…


From the mail bag…

I’d like to say that I’ve had a very positive experience with the RGB backlit LCD.

I have incorporated it into an Arduino-based dual-stage temperature controller that keeps a refrigerator at whatever temperature I set it with a front-panel switch (used for brewing beer).  When the temperature is within 1 degree of the setpoint, the display is green.  When it turns on the 110VAC to the cooling outlet (fridge power), it turns the display blue, and when it turns on the heating outlet (40W light bulb), it turns the display red.

It’s a great application for that display and has impressed a few people. I’d be willing to share some pictures if you’re interested. It uses three of your TMP36 sensors and an Uno.

p.s. It also incorporates an XBee so I can control the temperatures remotely (it’s in another building), but I can receive ambient air, ambient fridge air, and carboy temperatures for logging.  Remote control is handy because of the temperature fluctuations required for lagering that take place over the course of days.  Might as well automate that instead of walking out and manually changing the setpoints, right?  🙂


You can get the RGB LCD(s) here, here and 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, or even use Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for MakeCode, CircuitPython, 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 13,000+ makers on Adafruit’s Discord channels and be part of the community! http://adafru.it/discord

CircuitPython 2019!

Have an amazing project to share? The Electronics Show and Tell with Google Hangouts On-Air is every Wednesday at 7:30pm 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/

Maker Business — A list of companies owned by Amazon. It’s big.

Wearables — Raid the kitchen

Electronics — Capacitor ESR

Biohacking — Vitamin-C + Gelatin for Accelerated Recovery

Python for Microcontrollers — Python snakes its way to the STM32, Serpente, and more!

Adafruit IoT Monthly — Adafruit IO Updates, RGB Stream Deck Message Panel, and more

Microsoft MakeCode — Welcome to the MakeCode Newsletter!

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


  1. Mike,
    That’s a really great idea. Nice looking project. Thanks for the inspiration.
    (update with beer pictures when available?)

  2. Great project and I would love to build one also. I’m also a brewer. Will you share your design?

    pgrunwald AT comcast.net

  3. Great job, my friend! Can’t wait to taste the beer 🙂

  4. Ditto- nice project! By the way, would you mind sharing your source for the nice bezel you used for the LCD display?
    (Gee, I sure wish Adafruit Industries had those! hint..hint)

  5. Very nice – I have been looking for just this type project for a growth chamber I am building. As above will you share the design?

  6. I saw this and was highly impressed. Nice work.
    I am also a Homebrewer and was wondering if you would be willing to share the planes to it.

  7. very cool . . . could this also work for a humidor ? It would need 70f degrees and 70% relative humidity

  8. I just ordered a display and sensors from here. I already have a Duemilanove 328. I ordered this relay board http://www.ebay.com/itm/Wrobot-2-Channel-Relay-Shield-/270741882972?pt=LH_DefaultDomain_0&hash=item3f0979485c

    I don’t plan on doing wireless but I did get the high density display so I can graph.

    I will post more when I’m a little further along.


  9. p.s. Junction Box can be found at Lowes: http://www.lowes.com/pd_10029-223-E987NR_0__?productId=3256598

Sorry, the comment form is closed at this time.