LILYGO T-RSC3 ESP32-C3 board features isolated RS232 & RS485 interfaces, 5 to 24V DC input

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.

ESP32-C3 board with RS232 and RS485

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

Lilygo T-RSC3 pinout diagramThe 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.


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1 year ago


Can you please contact me?
It’s about this sample or similar.


Brad F
1 year ago

Would this support ESPhome?

1 year ago

Another LILYGO device with the single-core RISC-V ESP32-C3 instead of the faster more capable dual-core Xtensa LX7 ESP32-S3, why? The price difference between the C3 and S3 is peanuts. There must be a better reason.

Where is the on-board antenna for the ESP32?

Brad F
1 year ago

I brought one, the antenna isnt onboard. It comes with a little antenna that clips on

1 year ago

I just ordered one, can anyone confirm if a) the USB C port can indeed provide power and b) if it also supports BT Classic (like other ESP32 modules)? Thanks!

8 months ago

FWIW mine bricked itself 15 minutes into using it. I emailed the company, they responded and asked me to send additional info, and I haven’t heard back since.

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