Much Touch
If you need dozens of capacitive touch sensors in your project, SPOKE will really speak to you as it helps make the world your input device.
Capacitive touch sensors are very convenient to use in a wide range of electronic devices. They make it incredibly easy to add inputs into just about any project — no buttons required. They are super simple to build, as well. A microcontroller with an open GPIO pin, a resistor, and a conductive surface is about all that one needs.
But what if you need a couple dozen capacitive touch sensors? And what if you do not want a tangle of wires and resistors running everywhere? It may not be especially challenging to build such a setup either, but it takes time. And of course every time you create a new project, you will need to go through the process again. Especially for some quick prototyping of an idea, this high startup cost can be enough to make a hacker think twice about even getting out their soldering iron. Nobody wants yet another project to file under “start on someday that never comes.”
An interesting tool named SPOKE seeks to simplify adding large numbers of capacitive touch sensors to your projects. It is a bare PCB in the shape of a circle with 27 exposed copper touch pads. Each pad is wired into a Raspberry Pi RP2040 microcontroller’s GPIO pin, and is also connected to a programmable RGB LED for cool effects triggered by touches, or whatever else your little heart desires.
The onboard RP2040 is programmed with CircuitPython by default to make development as quick and simple as possible. There are additionally a pair of STEMMA JST connectors that make it easy to get connected to the Adafruit ecosystem, or add your own custom hardware. These connectors expose ADC, I2C, and PWM pins, so integrating servos, potentiometers, and a variety of sensors with SPOKE is simple. SPOKE boards can even be daisy chained together if you really need a ton of capacitive touch inputs. 50, 80, or more inputs? No problem.
What can all these inputs be used for? Well, just about anything. A keyboard for a digital piano, interactive artwork, educational tools, games, or whatever else you happen to dream up is possible. And you are not just limited to touching the pads themselves — oh no, that would be too boring. The pads can be wired to any conductive object — most metals, pencils, conductive threads or filaments, and organic materials (yes, bananas are fair game!). Under certain conditions, even non-conductive materials can be used as touch sensors.
For the beginner, SPOKE will come with tutorials and lesson plans to get the creative juices (and code) flowing. And for more advanced hackers, a SPOKE Mini will also be available. The Mini version is, as you might expect, much more compact and is meant for embedding into other projects. The boards are not available just yet, but the Kickstarter page is up, and you can enter your information to get notified the minute that it does go live if you want to be among the first to get a SPOKE in your hands.