Documentation

Overview

The MCP2515 + TJA1050 module gives any 5V Arduino, ESP32, or other microcontroller a fully isolated CAN bus 2.0B interface in a single small board. Combined, the two chips handle the SPI-to-CAN protocol conversion (MCP2515 controller) and the differential physical-layer transceiver (TJA1050) needed to talk on a CAN bus — the same bus used in every car built since the late 1990s, plus industrial automation, marine electronics, drones, and any kind of long-distance, multi-drop communication where reliability matters.

Use it to read OBD-II data from a car (engine RPM, vehicle speed, throttle position, fuel level, error codes), build a CAN-based home / industrial automation network, communicate between Arduinos over a 40-meter twisted-pair link, or interface with a CAN-equipped sensor or actuator. The 8 MHz crystal sets the CAN clock; the included 120 ohm jumper terminator can be enabled or disabled via a solder bridge.

The module supports CAN bit rates from 5 kbps up to 1 Mbps. Standard ID (11-bit) and extended ID (29-bit) frames are both handled. With the popular MCP_CAN Arduino library or pythonCAN on a Pi, sending and receiving CAN messages takes about 10 lines of code.

At a Glance

Specifications

Pinout Diagram

Wiring Guide

Code Examples

Send a CAN Message (Arduino, MCP_CAN library)

#include <SPI.h>
#include <mcp_can.h>

MCP_CAN CAN(10);  // CS

void setup() {
  Serial.begin(115200);
  while (CAN.begin(MCP_ANY, CAN_500KBPS, MCP_8MHZ) != CAN_OK) {
    Serial.println("CAN init fail; retrying");
    delay(100);
  }
  CAN.setMode(MCP_NORMAL);
  Serial.println("CAN init ok");
}

void loop() {
  unsigned char data[] = {0xDE, 0xAD, 0xBE, 0xEF, 0xCA, 0xFE, 0x00, 0x00};
  byte sndStat = CAN.sendMsgBuf(0x100, 0, 8, data);
  Serial.println(sndStat == CAN_OK ? "sent" : "fail");
  delay(1000);
}

Receive a CAN Message (Arduino, MCP_CAN library)

#include <SPI.h>
#include <mcp_can.h>

MCP_CAN CAN(10);  // CS

void setup() {
  Serial.begin(115200);
  while (CAN.begin(MCP_ANY, CAN_500KBPS, MCP_8MHZ) != CAN_OK) {
    delay(100);
  }
  CAN.setMode(MCP_NORMAL);
}

void loop() {
  if (CAN_MSGAVAIL == CAN.checkReceive()) {
    long unsigned int rxId;
    unsigned char len, buf[8];
    CAN.readMsgBuf(&rxId, &len, buf);
    Serial.print("ID: 0x"); Serial.print(rxId, HEX);
    Serial.print("  data:");
    for (int i = 0; i < len; i++) {
      Serial.print(' '); Serial.print(buf[i], HEX);
    }
    Serial.println();
  }
}

Frequently Asked Questions