Yo-Yo Machines Kit 3 - Knock Knock

by Pimoroni

Knock on one Knock Knock box and the other box knocks too (try saying that three times fast). It’s like they’re a single object that somehow appears in two places at the same time. Magic!

How to use Knock Knock

Knock Knocks come in pairs and are connected on the internet. The noise made by tapping on the box is is picked up by a piezo sensor inside and used to trigger a solenoid in its remote partner. It’s still kind of magic, if you think about it.

This kit contains everything you'll need to make your automated door knocker!

  • 2 x microUSB cable
  • 2 x ESP32S board
  • 2 x Mini breadboard
  • 2 x IRF520 MOSFET module
  • 2 x mini solenoid
  • 2 x 1M resistor
  • 4 x WAGO 2 way connector
  • 2 x Piezo Transducer
  • Male to male jumper lead selection

The USB cables that are included in the kit will let you power your units from any USB port. If you'd rather plug your device/s into a plug socket you can use a microUSB power supply to do that (not included, but we sell ones that will work here).

Click here for the full build instructions

Knock Knocks create a space of real time fun

Knock Knocks are made to be played with when you are both around — once sounds have played, no trace is left behind. But they’re quick, and they’re simple: all you’ve got to do is tap on your box and listen for a reply. What might you do with them?

  • Send a quick knock-knock to say hello and indicate your presence.
  • A simple call-and-response (‘shave and a haircut’) can give a brief sense of togetherness with your remote partner.
  • Try more elaborate rhythm games – the response should be quick enough that you can jam together for hours.
  • If you’re bored with social media, maybe its time to learn Morse code?

We build the Knock Knock mechanism into a simple cardboard box, but you can try using the solenoid with different objects and surfaces. You might position it to start a wine glass ringing, in an homage to Droog Design’s droog doorbell doorbell. You could try using it with that cymbal you keep as a reminder of your days in the band. Or maybe attach pins to them and create a situation of mutually assured balloon destruction? Go ahead and play – that’s what they’re for!

Who we are

We’re from the Interaction Research Studio, a team of designers and technologists at Goldsmiths, University of London. UKRI is supporting us to develop Yo–Yo Machines to show how research can have real-world impacts.

Visit our Yo-Yo Machines Website for more information about the project.

Contact us via email interaction@gold.ac.uk or share your designs in the Answers Forum.

40 customer reviews

5 years ago
A bit overpriced in comparison of most other BME680 sensors available online but with this one, you're sure it's working with the Adafruit libraries. I had this issue when buying 2 BME280 sensors from China, one of the two was actually a BMP280 in stead of BME280 so, it couldn't work with the library even if written on the article description as compatible.
by Melvin about BME680 Breakout - Air Quality, Temperature, Pressure, Humidity Sensor via REVIEWS.io
6 years ago
Love the BME680. Very easy to install and the Example files are great for getting started. Have found out from this Pimoroni Forum post : https://forums.pimoroni.com/t/bme680-air-quality-low/6293/9 that the whole AQ subject is very complex, however It's a really interesting topic and one that I am looking forward to understanding better! I'd assumed that it was only detecting VOCs (volatile organic compounds) but there's a hint that it might be detecting other gases. (I'm using a Breakout Garden pHAT with PiZero W, BME680 and 11x7 matrix to show an AQ score.)
by Anne about BME680 Breakout - Air Quality, Temperature, Pressure, Humidity Sensor via REVIEWS.io
6 years ago
I appreciate the thought put into the design of this board. It is nice that the pins line up with the GPIO, it’s easier to assemble and more presentable to have around the house. I also appreciate that their software has a “try” statement that looks for an Adafruit addressed chip as well as this Pimoroni one, since I have a mix of both around. Very good product, very much recommend it!
by Paul about BME680 Breakout - Air Quality, Temperature, Pressure, Humidity Sensor via REVIEWS.io
6 years ago
The board is high quality and easy to mount (on a featherwing proto) - note to Pimoroni (perhaps you could develop sensors already mounted on featherwing format?). The driver software is a little harder to get working than I expected - still can't see have to get the AQI (air quality index) as an output from the Bosch library or through the wrapper Adafruit library.
by Anonymous about BME680 Breakout - Air Quality, Temperature, Pressure, Humidity Sensor via REVIEWS.io
6 years ago
I am glad I lived long enough to see this awesome technology! I was a bit out of practice with the soldering iron but even I managed to sort out the connection to the Raspberry Pi. It is now being used to monitor the environment in conjunction with a ground source heat pump via Home Assistant. Thank you very much!
by Gerald about BME680 Breakout - Air Quality, Temperature, Pressure, Humidity Sensor via REVIEWS.io
7 years ago
Very nice all in one sensor for most basic Environmental sensors. The Air Quality sensor (Gas Ohm resistance detection) does take awhile to stabilize (at least 20 min on first start, about 5 for ones after that). It might get better as I use it more, as I only used it for about 12 hours.
by Chad about BME680 Breakout - Air Quality, Temperature, Pressure, Humidity Sensor via REVIEWS.io
7 years ago
Up and running in minutes after a false start but recovered quickly owing the prompt technical support. Good excuse to refresh minimal soldering skills. Robust module supersedes previous models. Temperature (with humidity) sensors are a dime a dozen, the barometric sensor is an added plus but the air quality sensor is the deal breaker for the price.
by Matha about BME680 Breakout - Air Quality, Temperature, Pressure, Humidity Sensor via REVIEWS.io

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