LILYGO T-SimHat CAN RS485 Relay 5V

Overview

The LILYGO T-SimHat is an expansion module designed to attach to compatible LILYGO SIM-series development boards, adding industrial communication interfaces and relay control capabilities. It is particularly useful for edge IoT nodes that need to interface with industrial equipment using CAN bus or RS485 protocols alongside cellular connectivity from the host board.

The module provides optocoupler isolation on both the CAN bus and RS485 interfaces, protecting the host board and connected microcontroller from voltage transients and ground loops common in industrial environments. Three relay outputs (HRS4H-S-DC5V) are available, each with a blue LED work indicator, and can be ordered pre-soldered or requiring user soldering depending on the variant chosen.

Available in three variants: H607 (3-way relays, not pre-soldered), H608 (3-way relays, pre-soldered), and H559 (CAN RS485 Relay combined). Note that this module is not compatible with the T-A7670G R2 With GPS or the T-SIM7600 series boards.

This expansion board is ideal for building smart energy meters, industrial equipment monitors, building automation controllers, and any application requiring reliable serial bus communication combined with relay switching over a cellular or Wi-Fi connected platform.

Firmware Compatibility

• Arduino: Supported via the host board's Arduino environment. Libraries for CAN bus (e.g., arduino-CAN) and RS485 (SoftwareSerial or HardwareSerial) can be used.
• ESP-IDF: Supported via the TWAI (Two-Wire Automotive Interface) driver for CAN and UART drivers for RS485.