WSAL10771 – RS485 CAN Shield/en

Documentation notice: This technical documentation was independently rewritten from an archived supplier source. Check technical details and commands against the product version and manufacturer documentation before use.

Summary

A concise technical introduction to the Waveshare RS485 CAN Shield for NUCLEO/XNUCLEO boards, covering the MAX3485 and SN65HVD230 chip functions, pin mapping, and example programs for transmitting and receiving.

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WSAL10771 – RS485 CAN Shield

Technical overview

The shield uses the standard Arduino header and is compatible with UNO, Leonardo, NUCLEO, and XNUCLEO boards.
RS485 function is provided by the MAX3485 transceiver (3.3 V), operating in half-duplex mode; A and B are the differential signal pins.
CAN function is provided by the TI SN65HVD230 (3.3 V), offering high-speed, slope, and wait modes controlled via the RS pin.
On the Xnucleo, D14 (PB9) and D15 (PB8) default to CAN TX/RX; remapping to CAN1 requires GPIO_PinRemapConfig(GPIO_Remap1_CAN1, ENABLE).
D7 (PA8) controls RS485 direction: high level = transmit, low level = receive.
D8 (PA9) and D2 (PA10) are UART1 TX/RX; jumper JP4 can switch to UART2 (D0/D1).
Two shields are wired together by connecting CANH to CANH and CANL to CANL, and A to A and B to B.
Example code runs under mbed + STM32 library; CAN uses CAN_Transmit / CAN_Receive, while RS485 uses Serial objects (printf/scanf).

Commands and examples – verify before use:

GPIO_PinRemapConfig(GPIO_Remap1_CAN1, ENABLE);
CAN_Config();
CAN_Transmit(CAN1, &TxMessage)
CAN_Receive(CAN1, CAN_FIFO0, &RxMessage)
RS485.printf(...)
RS485.scanf("%s", s)

Notes and version constraints

The shield requires a 3.3 V supply; on UNO/Leonardo the CAN function cannot be used due to hardware limitations.
Remapping PB9/PB8 to CAN1 is version-sensitive and must be set in firmware.
Jumper JP4 must be configured correctly when using UART2 (D0/D1) as the RS485 serial port.
The demo programs assume a specific Xnucleo-F103RB with STM32F103R; compatibility with other MCUs is not guaranteed.
No safety, certification, or warranty information is present in the source – do not make assumptions.

Source and revision record

RS485 CAN Shield - Waveshare Wiki
Source revision: 69188
Captured: 2026-08-30T02:40:09+00:00
SHA-256: 20376c75164b30b97179ee73f32e2f50ed8427647907bb4ccbcb35ed646f09a3