1. Introducció
This manual provides detailed instructions for the Waveshare RS485 CAN Expansion Board, designed for seamless integration with the Jetson Nano. The board offers robust RS485 and CAN communication capabilities, featuring digital isolation and built-in protection circuits for enhanced reliability in various applications.
2. Contingut del paquet
The image displays the Waveshare RS485 CAN Expansion Board along with mounting hardware (standoffs and screws) included in the package.
El paquet normalment inclou:
- Waveshare RS485 CAN Expansion Board
- Mounting hardware (standoffs and screws)
3. Característiques
Un acabatview of the key features of the RS485 CAN Expansion Board, including its GPIO header, CAN controller, RS485 function, TVS, and digital isolation.
- Standard 40-pin GPIO extension header for direct attachment to Jetson Nano.
- Onboard CAN controller MCP2515 via SPI interface, paired with SIT65HVD230DR transceiver.
- Integrated digital isolation chip for safer signal communication, improved stability, and anti-interference.
- RS485 function controlled via UART, supporting half-duplex communication with automatic TX/RX control (no programming required). Onboard transceiver SP3485.
- Onboard Transient Voltage Suppressor (TVS) for effective suppression of surge voltage i transient spike voltage in the RS485 transceiving circuit, providing lightning protection and anti-electrostatic capabilities.
- Reserved control pins allow compatibility with other control boards.
- Volum de funcionament de 3.3 Vtage.
- 3.0mm mounting hole size.
4. Especificacions
Detailed technical specifications of the Waveshare RS485 CAN Expansion Board, including controller types, operating voltage, i dimensions.
| Paràmetre | Valor |
|---|---|
| Controlador CAN | MCP2515 |
| Transceptor CAN | SIT65HVD230DR |
| RS485 Transceiver | SP3485 |
| Vol. Operatiutage | 3.3 V |
| Mida del forat de muntatge | 3.0 mm |
| Dimensió | 100 × 79 mm |
5. What's On Board (Component Overview)
An annotated diagram highlighting the main components on the RS485 CAN Expansion Board, including the CAN controller (MCP2515), CAN transceiver (SIT65HVD230DR), RS485 transceiver (SP3485), digital isolator (ADUM1412), power isolator (B0505LS), and indicators.
- CAN Controller: MCP2515
- CAN Transceiver: SIT65HVD230DR
- RS485 Transceiver: SP3485
- Power Isolator: B0505LS
- Digital Isolator Chip: ADUM1412
- Optocoupler Isolation Chip: PC817X3CSP9F
- TVS (Transient Voltage Suppressor)
- RXD & TXD Indicator
- Indicador d'alimentació
- Power Chip: RT9193-33
6. Definició del pin
A diagram illustrating the pinout and functions of the 40-pin GPIO header on the RS485 CAN Expansion Board, showing 5V, GND, RS485 TX/RX, CAN SPI, and other control pins.
The 40-pin GPIO header provides the following connections:
- 5 V: Font d'alimentació de 5 V
- GND: Terra
- TX: Transmissió RS485
- RX: Recepció RS485
- P17: Not connected, automatic TX/RX control by default
- MOSI: CAN SPI Data Input
- MISO: CAN SPI Data Output
- SCK: CAN SPI Clock Input
- CE0: CAN SPI Chip Select
- INT: CAN SPI Interrupt
7. Configuració i instal·lació
This image shows the Waveshare RS485 CAN Expansion Board connected to a Jetson Nano B01 4GB Version and a 2GB Version, demonstrating how it attaches to the 40-pin GPIO header.
- Prepare Jetson Nano: Ensure your Jetson Nano is powered off and disconnected from any power source.
- Attach Expansion Board: Carefully align the 40-pin GPIO header of the RS485 CAN Expansion Board with the corresponding header on your Jetson Nano. Gently press down until the board is securely seated.
- Assegurar amb maquinari: Use the provided standoffs and screws to firmly attach the expansion board to the Jetson Nano, ensuring stability.
- Connecteu els perifèrics: Connect your RS485 or CAN devices to the appropriate terminal blocks on the expansion board. Ensure correct polarity for RS485 (A, B, G) and CAN (H, L, G) connections.
- Encès: Once all connections are secure, power on your Jetson Nano.
8. Instruccions de funcionament
A visual representation of the RS485 and CAN functions on the board, highlighting the SP3485 RS485 transceiver, MCP2515 CAN controller, and SIT65HVD230DR CAN transceiver, and noting automatic TX/RX status switching.
8.1 Comunicació RS485
- The RS485 function operates via the UART interface of the Jetson Nano.
- It supports half-duplex communication.
- The onboard SP3485 transceiver features automatic TX/RX control, eliminating the need for software-based direction control.
- Refer to the Jetson Nano documentation for configuring the UART pins for communication.
8.2 CAN Communication
- The CAN function is managed by the MCP2515 controller, which communicates with the Jetson Nano via the SPI interface.
- The SIT65HVD230DR acts as the CAN transceiver.
- Ensure the SPI interface on your Jetson Nano is enabled and configured correctly.
- Software libraries and examples for CAN communication on Jetson Nano are typically available from Waveshare's official resources.
8.3 120R Resistor Selection
The board includes jumpers for enabling or disabling the 120Ω termination resistors for both RS485 and CAN buses. Set these jumpers according to your network topology:
- ACTIVITAT: Enables the 120Ω termination resistor. Typically used at the ends of a bus line.
- DESACTIVAT: Disables the 120Ω termination resistor. Used for intermediate nodes on a bus line.
9. Manteniment
The Waveshare RS485 CAN Expansion Board is designed for durability and requires minimal maintenance. Follow these guidelines to ensure optimal performance and longevity:
- Mantenir net: Regularly clean the board with a soft, dry brush or compressed air to remove dust and debris. Avoid using liquids or harsh chemicals.
- Condicions ambientals: Operate the board within its specified temperature and humidity ranges. Avoid extreme conditions.
- Connexions segures: Periodically check all connections (GPIO header, terminal blocks) to ensure they are secure and free from corrosion.
- Actualitzacions de firmware: Keep your Jetson Nano's operating system and any relevant communication libraries updated to benefit from performance improvements and bug fixes.
10. Solució De Problemes
If you encounter issues with your RS485 CAN Expansion Board, consider the following troubleshooting steps:
- Sense alimentació/Indicadors apagats:
- Ensure the Jetson Nano is powered on correctly.
- Verify the expansion board is securely seated on the Jetson Nano's GPIO header.
- Communication Errors (RS485/CAN):
- Check wiring connections to external devices for correct polarity and secure contact.
- Verify the 120Ω termination resistor jumpers are set correctly for your network configuration.
- For RS485, confirm UART settings (baud rate, parity, stop bits) match between the Jetson Nano and the connected device.
- For CAN, ensure the SPI interface is enabled and configured on the Jetson Nano, and that CAN bus parameters (baud rate) are consistent.
- Check for conflicts with other devices or software using the same UART or SPI pins.
- Connectivitat intermitent:
- Inspeccioneu si hi ha connexions soltes o cables danyats.
- Ensure proper grounding of all connected devices.
- Environmental interference might be a factor; ensure proper shielding if necessary.
- Problemes de programari:
- Consult Waveshare's official documentation and examples for software setup and usage.
- Ensure necessary drivers or libraries are installed and correctly configured on your Jetson Nano.
11. Cotes del contorn
A technical drawing showing the precise dimensions of the Waveshare RS485 CAN Expansion Board in millimeters, useful for integration and enclosure design.
The board dimensions are approximately 100mm x 79mm. Refer to the diagram for detailed measurements and mounting hole positions.
12. Recursos addicionals
12.1 Vídeo oficial del producte
An official product video from Waveshare demonstrating the RS485 CAN Expansion Board for Jetson Nano, showcasing its features and potential applications.
12.2 Online Documentation
For the latest documentation, development resources, and example code (including Python examples), please visit the official Waveshare product page or their Wiki.
13. Garantia i Suport
Information regarding product warranty and technical support can typically be found on the Waveshare official website or through your point of purchase. Please refer to those resources for details.
