Xtech
Keyboards & Input Devices
RoenDi
An open source rotary encoder with a 1.27" TFT customizable display
Xtech
Keyboards & Input Devices
RoenDi is a visually adaptable rotary encoder capable of displaying customized graphics. Having a built-in screen allows it to provide visual feedback unlike any other encoder we’ve seen. RoenDi is designed with simplicity and versatility in mind. Just connect a MicroUSB cable or ST-LINK connector, upload your code to the MCU, and you’re ready to go!
The potential uses for RoenDi are up to your imagination, and we’d love to see the unique applications you come up with. Some examples of potential uses are:
With RoenDi, you can create unique custom interfaces that stand out from the rest and provide responsive visual feedback to the user.
RoenDi uses a powerful STM32L433 MCU, which can be programmed with the Arduino IDE. This makes it easier for novice makers to get involved, while allowing experts to enjoy the benefits of ST’s inline debugging tools. The code base from ST and Arduino is robust, which means there is plenty of sample code to work with.
To help get you started customizing your RoenDi, we have provided sample code using several well documented code libraries. For Arduino lovers, we have provided examples using the Adafruit GFX library, which means you can add text, images, and other graphical objects to the screen with just a few lines of code. If you prefer STM32CubeIDE, we have provided examples using the robust TouchGFX library, which is designed specifically for interactive display interfaces like RoenDi.
Below is an demonstration of RoenDi being used as a combination lock:
RoenDi hardware and software are open source, so you can modify and customize its components as you wish. We also worked to build RoenDi with readily available off-the-shelf parts, so you can modify and repair your RoenDi if you ever need to.
The encoder-and-displays MCU also contain a multitude of available IO pins to work with. They are broken out to pads on the side of the PCB so you can easily connect to the UART, CAN, I²C, PWM, DAC, and SAI peripherals. These interfaces can be used to communicate with a large variety of third-party ICs, including LED drivers, speakers, motors, and sensors that detect temperature, humidity, and light, to name just a few examples. One of the great things about the STM32L4 MCU is that all pins tolerate 5 V for easy interfacing.
RoenDi can also be used in conjunction with other connected devices, such as Wi-Fi and Bluetooth modules, which makes RoenDi great for wireless interfaces and IoT applications.
| RoenDi | Grayhill TE-M32M1-A11C | SLB-10-40-0 | |
|---|---|---|---|
| Material | Aluminum & PLA | Stainless & Plastic | Aluminum & Plastic |
| Power supply | 3.3 V DC to 5 V DC | 4.75 V DC to 18 V DC | 3.3 V DC |
| Resolution | 240 x 240 | 320 x 300 | 240 x 204 |
| Display colors | 4 K / 65 K / 262 K | unknown | 262 K |
| MCU + on board memory | yes | yes | no |
| Open source & open hardware | yes | no | no |
| Customizable encoder body | yes | no | no |
| Breakout for GPIO | yes | no | no |
| Capable for standalone applications | yes | yes | no |
| Touch sensor | no | yes | no |
| Brightness | 400 Cd/m2 | 200 Cd/m2 | unknown |
| Arduino compatible | yes | no | yes |
| Boot time | less then 1 second | 5 seconds to O.S. | N/A (display only, no processor) |
| USB | yes | yes | no |
| CAN | yes | yes | no |
| SAI, PWM, I²C, DAC, RTC | yes | no | no |
| Price | $135 | $212 | $131 |
All hardware and software documentation for RoenDi will be published and openly maintained in our GitHub repositories.
We will also be releasing a series of tutorials that will walk you through the process of using RoenDi for various applications.
Produced by Xtech in Rousse, Bulgaria.
Sold and shipped by Crowd Supply.
Everything you need! Parts included: Main encoder board, Display board with connection cable, Matte black aluminum body, ST-LINK adaptor board + cable
