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 can’t wait to see the unique applications you all 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.
|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|
|Brightness||400 Cd/m2||200 Cd/m2||unknown|
|Boot time||less then 1 second||5 seconds to O.S.||N/A (display only, no processor)|
|SAI, PWM, I²C, DAC, RTC||yes||no||no|
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.
Production RoenDi boards will be fabricated and quality assured by PCBWay, a contract manufacturer with whom we have worked to produce various RoenDi prototypes. Each board will be tested at their factory to ensure consistent quality, and then assembled in Bulgaria as soon as all components are available after the campaign is completed.
RoenDi uses a STM32L4 as its primary microprocessor. As of February 2022, due to the worldwide chip shortage, the availability date for the STM32L4 is April 2023, which means the necessary components will be available to be ordered in the second quarter of 2023. From there, we will continue the manufacturing, assembly, and testing process, so that our products can be sent to Mouser and distributed worldwide to our backers.
After testing and packaging the production batch, we will ship all RoenDi units to Crowd Supply’s fulfillment partner, Mouser Electronics, who will distribute them to backers worldwide. You can learn more about Crowd Supply’s fulfillment service under Ordering, Paying, and Shipping in their guide.
Due to the worldwide chip shortage, the RoenDi project could be further delayed if factory lead times increase yet again. We are researching alternative ICs in case this happens, and we will provide updates on the production process as manufacturing moves forward.
"Electronic enthusiasts, hobbyists and engineers looking for an open source rotary encoder complete with a circular 1.2 inch programmable TFT circular display may be interested in the Roendi."
"This rotary encoder is equipped with an STM32L433 microcontroller which is based on a high-performance ARM Cortex-M4 32-bit RISC core operating at a frequency of up to 80MHz"
"For those seeking an open source rotary encoder with a 1.28" TFT round display, the Roendi is just the thing for you."
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
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