A rotary encoder is a position sensor that converts the motion of a knob into an output signal that is used to determine the direction the knob is being rotated. Rotary encoders are usually attached to motors and are used to ensure that the motor stator and rotor positions are always synchronized to drive supplied current.
There are many kinds of rotary encoders these days but if you are looking for one that is completely open-source with a circular 1.2 inch programmable TFT circular display, then you may want to consider 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. The low-power MCU embeds high-speed memories (256 Kbyte flash, 64 Kbyte SRAM), a Quad SPI Flash memories interface, and an extensive range of enhanced I/Os and peripherals. The microcontroller also has support for standard and advanced communication interfaces namely: I2Cs, SPIs, USARTs and UART, SAI, SDMMC, CAN, USB full-speed device crystal less, and SWPMI.
Roendi is also said to have a 1.28 inch TFT round display and an Alps Alpine 15 Pulses/30 Detent encoder. It can be programmed using Arduino IDE or ST-LINK/V2, and it offers a great programmable user interface that can be applied to many applications and projects depending on your needs. “All pins not used by the encoder are broken out to the peripheral of the board.”
Features and Specifications of Roendi Include:
- STM32L433 MCU which features an Arm Cortex-M4 running at 80 MHz and supporting SPI, I2C, I2S, CAN, and USART communication.
- Round 1.28 inch TFT LCD Display
- Rotary Encoder:
- Pulses: 15
- Detents: 30
- 128 Mbits NOR Flash
- LDO: 3 V 400 mA
- Aluminum or 3D printed body. (Seems like there will also be CAD files for custom prints too)
- Software: Can be programmed with STM32CubeIDE 1.6.1 or Arduino IDE
Application Scenario:
- Can be integrated into projects as a unique user interface
- Can also be used as a standalone development board
Use cases:
- Can be added to home automation systems
- Can be used for a Custom HID device, and,
- Can also be an excellent interface for controlling volume, light, and temperature.
The project will soon be available on the CrowdSupply page, but you can sign up now to get notified when it eventually goes live, and also to get other useful updates about it.
The rotary encoder is completely open-source and open hardware. Further details including its schematics, pinouts, demo software, and enclosed CAD files, are on GitHub.