RS-485 + CAN bus + DCDC Converter Shield for WeMos Mini is a small three-in-one board to fit on top of WeMos Mini (ESP32) microcontroller boards:

• RS485 to TTL Serial transceiver with automatic flow control connects UART compatible GPIO pins on the microcontroller.
• CAN bus Transceiver is suitable for 12 V and 24 V systems and it connects to ESP32 integrated CAN controller via GPIO pins.
• DC/DC Converter allows powering the board and the microcontroller with 3.3 V from ~12 V DC source.

This board offers an easy and compact way to connect NMEA-2000 bus and/or one NMEA-0183 (RS-485/RS-422) device to WiFi network on a small boat using NMEA2000-Gateway with ESP32 software getting power from the NMEA-2000 bus or separate ~12 V DC source like 12 V battery.

Features

• 3.5mm screw terminals
• Supply voltage: 12 VDC (3.8V-32V)
• GPIO voltage: 3.3 V
• DC/DC converter: AP63203
• RS-485 transceiver with auto direction control: THVD1406
• RS-485 interface connects to secondary UART on the WeMos Mini ESP32 boards
• CAN bus transceiver: SN65HVD232
• Optical isolation: none
• GPIO pins for WeMos D1 Mini ESP32:
  •  RS-485
    • RX: GPIO16
    • TX: GPIO17
  • CAN bus
    • RX: GPIO19
    • TX: GPIO18

Resources

• Design files on GitHub
• ESPHome CAN Bus component
• ESPHome ModBus component
• NMEA2000-Gateway with ESP32 by Andreas Vogel

Buy

• Bare PCB: 3€
• Pre-assembled: 21€
• Pre-assembled with terminals: 26€