> SPI to CAN bus gateway module for Arduino-based prototyping with UIROBOT servo stepper motors and control systems --- ## Product Overview The UI-MCP2515 is a compact SPI-to-CAN module based on the MCP2515 CAN controller and TJA1050 transceiver. It enables microcontrollers with SPI interfaces to communicate on a CAN 2.0B bus, allowing Arduino and other MCU platforms to control UIROBOT servo stepper motors and I/O controllers seamlessly. By combining Arduino, the UI-MCP2515 module, and UIROBOT motor drivers (e.g., UIM342), users can efficiently create a complete and reliable motion control system for rapid prototyping, educational projects, and small-scale automation. ### Key Features :::grid{cols=2 style=card} **CAN 2.0A/B Support** Standard and extended frame formats. Baud rates configurable from 125K to 1M bps. **SPI Interface** High-speed SPI communication with the host MCU. Does not occupy UART or I2C pins. ::: :::grid{cols=2 style=card} **Arduino Compatible** Directly compatible with Arduino Uno, Mega, and other SPI-based development boards. No additional wiring required. **Rapid Prototyping** Ideal for proof-of-concept projects, educational use, and field debugging before deploying production gateways. ::: --- ## Technical Specifications ### Absolute Maximum Ratings | Parameter | Specification | |-----------|---------------| | Ambient temperature under bias | -40°C ~ +85°C | | Storage temperature | -65°C ~ +150°C | | Supply Voltage (from Arduino) | 5 VDC | ### Communication Interface | Parameter | Specification | |-----------|---------------| | CAN Controller | MCP2515 | | CAN Transceiver | TJA1050 | | Interface | SPI | | CAN Protocol | CAN 2.0A / 2.0B | | CAN Baud Rate | 125K / 250K / 500K / 1M | | CAN Physical | 2 wires, CANH, CANL, twisted pair | ### Hardware Pinout | Pin | Function | Connect To | |-----|----------|-----------| | VCC | Power (5V) | Arduino 5V | | GND | Ground | Arduino GND | | CS | SPI Chip Select | Arduino Pin 10 | | SI | SPI MOSI | Arduino Pin 11 | | SO | SPI MISO | Arduino Pin 12 | | SCK | SPI Clock | Arduino Pin 13 | | INT | Interrupt Output | Arduino Pin 2 | | CANH | CAN Bus High | CAN Bus High | | CANL | CAN Bus Low | CAN Bus Low | --- ## Hardware Wiring ### Arduino Connection  ### Pin Connections (Text Reference) ``` +------------------+ +------------------+ | Arduino | | UI-MCP2515 | +------------------+ +------------------+ | Pin 10 (CS) ---+---->| CS | | Pin 11 (MOSI)---+---->| SI | | Pin 12 (MISO)<--+-----| SO | | Pin 13 (SCK) ---+---->| SCK | | Pin 2 (INT) <--+-----| INT | | 5V ---+---->| VCC | | GND ---+---->| GND | +------------------+ +------------------+ CAN Side: +------------------+ | UI-MCP2515 | +------------------+ | CANH --------->| CAN Bus High | CANL --------->| CAN Bus Low +------------------+ ``` ### System Wiring (with UIM342 Motor) ``` Arduino UI-MCP2515 UIM342 Motor +----------+ +-------------+ +------------+ | CS -> 10|--------->| CS | | | | MOSI ->11|--------->| SI | | CANH <----+---- CAN Bus High | MISO <-12|<---------| SO | | CANL <----+---- CAN Bus Low | SCK ->13|--------->| SCK | | V+ <----+---- 24V DC | INT <-2 |<---------| INT | | GND <----+---- GND | 5V |--------->| VCC | | | | GND |--------->| GND | +------------+ +----------+ +-------------+ ``` > **Note**: Connect a 120Ω termination resistor between CANH and CANL at both ends of the CAN bus for reliable communication. --- ## Quick Start This section explains how to quickly build and run a motor system consisting of UIM342 motors and 1 UI-MCP2515 module with Arduino. ### Required Materials | Item | Qty | Description | |------|:---:|-------------| | UIM342 Series Motor | 1+ | CAN bus smart motor | | Arduino UNO (or compatible) | 1 | Microcontroller board | | UI-MCP2515 Module | 1 | SPI to CAN gateway | | 24V DC Power Supply | 1 | For motor power | | USB Cable | 1 | For Arduino programming | | Arduino IDE | 1 | Development environment | ### Step 1 — Install Arduino IDE Visit the official Arduino website: [arduino.cc](https://www.arduino.cc/en/software/) Download and install the version compatible with your operating system. ### Step 2 — Download Sample Code 1. Visit [uirobot.com](https://uirobot.com) 2. Navigate to **Support → Download Center** 3. Download the **UI-MCP2515** sample code package 4. Extract the downloaded ZIP file ### Step 3 — Wire the Hardware 1. Connect UI-MCP2515 to Arduino per the wiring diagram above 2. Connect CANH/CANL to the UIM342 motor controller 3. Connect 24V DC power supply to the motor 4. **Double-check all wiring before powering on** ### Step 4 — Add Required Libraries In Arduino IDE: 1. Navigate to **Sketch → Include Library → Add .ZIP Library** 2. Add the following libraries: - `arduino-mcp2515-master.zip` — For MCP2515 CAN communication - `m_UIrobotConfig.zip` — For UIM342 motor configuration ### Step 5 — Upload Code to Arduino 1. Open the sample `.ino` project file 2. Select the correct **Board** and **Port** in Tools menu 3. Click **Verify** to compile the code 4. Click **Upload** to upload to Arduino ### Step 6 — Open Serial Monitor 1. Once uploaded, open **Serial Monitor** from the upper-right corner 2. Set baud rate to **2,000,000** (or as specified in the sample code) 3. Observe the output to verify communication ### Default Parameters | Parameter | Default Value | |-----------|---------------| | CAN Baud Rate | 500 Kbps | | UIM342 Node ID | 5 | | SPI Clock | 8 MHz | | MCP2515 Crystal | 16 MHz | --- ## Sample Code ```cpp #include <SPI.h> #include <mcp2515.h> #define CS_PIN 10 struct can_frame canMsg; MCP2515 mcp2515(CS_PIN); void setup() { Serial.begin(115200); mcp2515.reset(); mcp2515.setBitrate(CAN_500KBPS, MCP_8MHZ); mcp2515.setNormalMode(); Serial.println("UI-MCP2515 Initialized"); } void loop() { // JOG command: speed 500 RPM canMsg.can_id = 0x05; // UIM342 Node ID (default = 5) canMsg.can_dlc = 8; canMsg.data[0] = 0x1D; // JV (Jog Velocity) canMsg.data[1] = 0xF4; // Speed low byte (500 = 0x01F4) canMsg.data[2] = 0x01; // Speed high byte canMsg.data[3] = 0x00; canMsg.data[4] = 0x00; canMsg.data[5] = 0x00; canMsg.data[6] = 0x00; canMsg.data[7] = 0x00; mcp2515.sendMessage(&canMsg); delay(100); // Send BG (Begin Motion) canMsg.data[0] = 0x16; // BG command canMsg.data[1] = 0x00; canMsg.data[2] = 0x00; canMsg.data[3] = 0x00; canMsg.data[4] = 0x00; canMsg.data[5] = 0x00; canMsg.data[6] = 0x00; canMsg.data[7] = 0x00; mcp2515.sendMessage(&canMsg); delay(2000); } ``` --- ## CAN Bus Precautions :::warning **WARNING** - Avoid star connections. When CAN cable length exceeds 20 meters, dedicated CAN cables should be used. The length of branch cable to each node should not exceed 20 cm. - It is recommended to connect a 120-ohm terminal resistor at both ends of the CAN bus. - **Strictly avoid hot-plugging while power is on**. Hot-plugging may lead to ground loss, causing burnout of multiple devices. - Connect all devices to a common ground. ::: --- ## Safety Precautions | Precaution | Consequence of Neglect | |------------|----------------------| | Do not use in humid, corrosive, flammable gas environments or near flammable substances | Fire / Malfunction | | Do not use the wire when soaked in oil/water | Fire / Malfunction | | Do not frequently power on/off | Malfunction | | Never modify, disassemble or repair by yourself | Fire / Malfunction | | Power supply voltage must meet product requirements | Malfunction | | Cut off power when not in use for long time | Fire / Malfunction | --- ## Video Tutorial :::video[How to Control UlM342 CANBUS Servo Stepper Smart Motors Using Arduino+ Ul-MCP2515](https://www.youtube.com/watch?v=GLb7F3KFpPc) ::: --- ## Downloads - 💻 [MCP2515 Datasheet](https://www.microchip.com/wwwproducts/en/MCP2515) - 💻 [Arduino CAN Library](https://github.com/coryjfowler/MCP_CAN_lib) - 📖 [StepEva3 User Manual V4.7 (PDF)](https://www.uirobot.com/uploads/files/Manual_StepEva3%20V4.7.pdf) - 📖 [uirSDK3 User Manual V4.7 (PDF)](https://www.uirobot.com/uploads/files/f30fdec2ef52855e328edf9abcbd1d4e.pdf) --- ## Related Documents - [UIM342 CAN Bus Smart Servo Stepper Motor Controller](/docs/uim342) - [UIM2513 RS232-CAN Gateway](/docs/uim2513) - [UIM2523 Ethernet-CAN Gateway](/docs/uim2523) - [CAN Bus Motion Control Gateways](/docs/motion-control-gateway) - [Quick Start Guide](/docs/quick-start) - [Arduino CAN Bus Examples](/docs/arduino-examples) --- *Last Updated: 2026-06-29 | Based on Application Note AN250903*