How to Use Matek AP_Periph CAN Digital Power Monitor, CAN-L4-BM: Examples, Pinouts, and Specs

The Matek AP_Periph CAN Digital Power Monitor (Model: CAN-L4-BM) is a high-precision power monitoring module designed for use in UAVs, robotics, and other embedded systems. It leverages the UAVCAN protocol for seamless integration with modern flight controllers and other CAN-enabled devices. This module provides real-time monitoring of voltage, current, and power consumption, making it an essential component for applications requiring accurate power management and telemetry.

• UAVs and drones for power monitoring and telemetry
• Robotics systems requiring precise energy management
• Remote monitoring of battery performance in embedded systems
• Integration with UAVCAN-enabled flight controllers for advanced power diagnostics

The following table outlines the key technical specifications of the Matek AP_Periph CAN Digital Power Monitor:

The Matek AP_Periph CAN Digital Power Monitor features the following pinout:

1. Power Connection: Connect the VIN+ and VIN- terminals to the positive and negative terminals of the power source (e.g., battery). Ensure the voltage is within the specified range (6V to 60V).
2. CAN Bus Connection: Connect the CANH and CANL pins to the corresponding CAN bus lines of your system. Use a 120-ohm termination resistor if the module is at the end of the CAN bus.
3. Power Supply: Provide a stable 5V power supply to the VCC pin. Ensure the GND pin is connected to the system ground.
4. Shunt Resistor: If measuring high currents, connect an appropriate external shunt resistor to the module. Ensure the shunt resistor is rated for the expected current range.

• UAVCAN Configuration: Configure the module's UAVCAN parameters (e.g., node ID) using a compatible UAVCAN configuration tool.
• Wiring: Use short, thick wires for the VIN+ and VIN- connections to minimize voltage drops and ensure accurate measurements.
• Calibration: Calibrate the module using the UAVCAN tool to ensure precise voltage and current readings.
• Firmware Updates: Periodically check for firmware updates from Mateksys to ensure compatibility with the latest UAVCAN standards.

To interface the Matek AP_Periph CAN Digital Power Monitor with an Arduino UNO, you will need a CAN transceiver module (e.g., MCP2515). Below is an example code snippet:

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

// Define CAN bus pins for MCP2515
#define CAN_CS 10  // Chip Select pin
#define CAN_INT 2  // Interrupt pin

MCP_CAN CAN(CAN_CS);  // Create CAN object

void setup() {
  Serial.begin(115200);
  while (!Serial);

  // Initialize MCP2515 CAN module at 500kbps
  if (CAN.begin(MCP_ANY, 500000, MCP_8MHZ) == CAN_OK) {
    Serial.println("CAN bus initialized successfully!");
  } else {
    Serial.println("CAN bus initialization failed!");
    while (1);
  }

  CAN.setMode(MCP_NORMAL);  // Set CAN module to normal mode
  Serial.println("CAN module set to normal mode.");
}

void loop() {
  // Check for incoming CAN messages
  if (CAN.checkReceive() == CAN_MSGAVAIL) {
    long unsigned int rxId;
    unsigned char len = 0;
    unsigned char rxBuf[8];

    // Read CAN message
    CAN.readMsgBuf(&rxId, &len, rxBuf);

    // Print received message ID and data
    Serial.print("Message ID: 0x");
    Serial.println(rxId, HEX);
    Serial.print("Data: ");
    for (int i = 0; i < len; i++) {
      Serial.print(rxBuf[i], HEX);
      Serial.print(" ");
    }
    Serial.println();
  }
}

Note: Ensure the MCP2515 library is installed in your Arduino IDE. This code initializes the CAN bus and listens for incoming messages from the Matek AP_Periph CAN Digital Power Monitor.

1. No Data on CAN Bus:

   • Cause: Incorrect wiring or missing termination resistor.
   • Solution: Verify the CANH and CANL connections. Add a 120-ohm resistor if the module is at the end of the CAN bus.

2. Inaccurate Measurements:

   • Cause: Improper calibration or incorrect shunt resistor value.
   • Solution: Recalibrate the module using the UAVCAN tool. Ensure the shunt resistor matches the expected current range.

3. Module Not Powering On:

   • Cause: Insufficient or unstable power supply.
   • Solution: Check the VCC and GND connections. Ensure a stable 5V supply is provided.

• Use a CAN bus analyzer to verify communication between the module and the flight controller.
• Check for firmware updates from Mateksys to resolve compatibility issues.
• Ensure all connections are secure and free from corrosion or damage.

By following this documentation, users can effectively integrate and utilize the Matek AP_Periph CAN Digital Power Monitor in their projects.