M5Stack M5Dial is a WiFi and Bluetooth-connected smart rotary knob with a round 1.28-inch touchscreen TFT display powered by an ESP32-S3 board, more precisely, the M5Stamp S3 IoT module.
The user-programmable device comes with a rotary encoder recording the position and direction of the knob, an RFID module, an RTC, a buzzer, and under-screen buttons, as well as two Grove connectors for expansion enabling all sorts of projects.
- Wireless MCU module – M5Stack M5Stamp S3 with
- SoC – Espressif Systems ESP32-S3FN8 dual-core 32-bit Xtensa LX7 microcontroller with AI vector instructions up to 240MHz, RISC-V ULP co-processor, 512KB SRAM, 2.4GHz WiFi 4 (802.11b/g/n), Bluetooth 5.0 BLE + Mesh, 8MB flash
- 2.4GHz 3D antenna
- USB – 1x USB Type-C port
- Expansion connectors for I/Os such as SPI, I2C, UART, ADC, and more
- Display – 1.28-inch TFT display with 240×240 resolution using GC9A01 driver, and FT3267 capacitive touchscreen controller
- RFID – WS1850S chip working at 13.56MHz, supporting ISO14443A, MIFARE and NTAG protocols
- Port A Grove connector with I2C (5V)
- Port B Grove connector with Input and Output (5V)
- Misc – Reset button
- Power Supply – 6-36V DC input via 2-pin terminal, or battery with charging circuit
- Power Consumption
- Standby current (battery-powered) – 1.9uA @ 4.2V
- Working current
- 140.6 mA @ 6V
- 82.5mA @ 12V
- 28.1mA @ 16V
- Dimensions – 45 x 45 x 32.3mm
- Weight – 46.6 grams
The M5Stamp S3 module found in the M5Dial smart rotary knob can be programmed with Arduino, the ESP-IDF, or the company’s UIFlow online IDE, but the documentation currently mostly focuses on Arduino support (see the library on GitHub) and also includes the PDF schematics and some datasheets.
Potential applications for the ESP32-S3-powered rotary encoder include smart home applications to control lights, air conditioning, and curtains, industrial automation, access control using RFID cards and/or tags, and other use cases that may benefit from a WiFi-connected knob with expansion capabilities.
M5Stack’s M5Dial can be purchased for $34.90 on the company’s online store. Note that it’s not the first smart rotary encoder with a round color display, as we covered several competing products in the past such as the SmartKnob View and the RoEndi rotary encoder, but the former is an open-source source that you need to build yourself and the latter is based on an STM32 MCU without WiFi connectivity. If you don’t care about the round shape of the display there are more ESP32-S3 boards with a rotary encoder and a rectangle display such as the LILYGO T-Embed or the Banana Pi BPI-Centi-S3 among others.
Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.