LILYGO T-RSC3 is a relatively compact ESP32-C3 board with WiFi 4 and Bluetooth LE 5.0 connectivity, support for RS232 and RS485 communication protocols through a DB9 connector and a terminal connector respectively, and a wide 5V to 24V DC power input.
LILYGO had already made an ESP32 board with CAN Bus and RS485 interfaces called the T-CAN485, but without any isolation. The new T-RSC3 offers both RS232 and RS485 interfaces, but no CAN Bus, protected by isolated transceiver modules that should make it safer to use in industrial environments.
LILYGO T-RSC3 board specifications:
- Wireless module – Espressif Systems ESP32-C3-MINI-1U module with ESP32-C3 RISC-V microcontroller @ 160 MHz with 400 KB SRAM, 2.4 GHz WiFi 4, Bluetooth 5.0 LE & Mesh, 4MB flash, and a u.FL antenna connector
- Industrial control interfaces
- RS232 via DB9 connector, RSM232MT5V isolated transceiver with 3000V isolation, 4.75~5.25V input, 5V/50mA output, baud rate from 1200 to 256,000 bps (see PDF datasheet)
- RS485 via 3-pin terminal block, RSM485MT5V isolated transceiver with 3000V isolation, 4.75~5.25V input, 5V/50mA output, baud rate from 1200 to 256,000 bps (see PDF datasheet)
- USB – 1x USB Type-C port I assume to program the ESP32-C3 firmware and possibly power the board when the 2-pin terminal is not used (TBC).
- Expansion – 12-pin female header with 3x GPIOs, UART, 5V, 3.3V, and GND
- Misc – Reset, Boot, and user (IO02) buttons, WS2812 RGB LED
- Power Supply – 5 to 24V via 2-pin terminal
- Dimensions – 67 x 56 x 18 mm
The company says the ESP32-C3 board is programmable with the ESP-IDF framework or the Arduino IDE, and provides Arduino code samples for WiFi, RS232 (simple and Modbus), and RS485 (simple and Modbus) in a GitHub repository for the board along with a firmware image and requires libraries that include ModbusMaster, Adafruit_NeoPixel, ESPAsyncWebServer, and WebSerial.
LILYGO T-RSC3 board can be purchased on Aliexpress for $19.07 with free shipping. But note that since Chinese New Year 2023 has just started, shipping will only take place around February 1. That should be about the same for most other sellers on Aliexpress.
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.