MATEK Mateksys CAN-L4-BM Digital Power Monitor

1. Introduction

The MATEK Mateksys CAN-L4-BM is a high-precision digital power monitor designed for advanced RC applications, including airplanes and drones. It integrates an STM32L431XC microcontroller and a TI INA239 power monitor IC to provide accurate battery voltage and current measurements via the DroneCAN protocol. This module is compatible with flight controllers such as the H743 V3 and is an essential component for DIY drone and RC aircraft enthusiasts seeking reliable power telemetry.

2. Specifications

3. Package Contents

The package includes the following items:

• 1 × CAN-L4-BM board
• 1 × JST-GH-4P to JST-GH-4P 20 cm silicon wire

4. Setup and Installation

Follow these steps for proper installation of your CAN-L4-BM Digital Power Monitor:

4.1 Physical Connection

The CAN-L4-BM board should be connected in-line between your battery and the Electronic Speed Controller (ESC) or other load. Ensure the positive wire is welded as close as possible to both sides of the current detection resistor for optimal accuracy.

4.2 Wiring Diagrams

Refer to the following diagrams for connecting the CAN-L4-BM to your flight controller:

4.3 Jumper Configuration

If your CAN wire is excessively long, it is recommended to bridge the "120R" jumper on the CAN-L4-BM board. This activates a 120 Ohm termination resistor, which can improve signal integrity over longer CAN bus segments.

5. Operating Instructions

5.1 Firmware

The CAN-L4-BM uses ARDUPILOT AP_PERIPH MATEKL431-BATTMON firmware. Ensure your flight controller's firmware is compatible and updated. Firmware updates for the CAN-L4-BM can typically be performed through a drone GUI tool.

5.2 Parameter Configuration

After connecting the CAN-L4-BM, configure the following parameters in your flight controller's software (e.g., Mission Planner, QGroundControl):

• CAN_S1_DRIVE=1: Set this parameter if the CAN-L4-BM is connected to CAN bus port 1.
• CAN_S2_DRIVE=1: Set this parameter if the CAN-L4-BM is connected to CAN bus port 2.
• BATTX.MONITOR=8: This parameter enables drone battery information monitoring. Replace 'X' with the battery number you are configuring (e.g., BATT1.MONITOR=8).

6. User Tips

• The large cushion at the bottom of the board is a dead cushion, meaning there is no active circuit network above it. This area can be used for mounting or additional insulation if needed.
• For optimal current sensing accuracy, weld the positive wire as close as possible to both sides of the current detection resistor.
• The two mounting ears on the board can be cut off if they are not required for your specific installation, allowing for a more compact footprint.
• If you are using a long CAN bus cable, bridging the "120R" jumper is recommended to ensure stable communication by providing proper bus termination.

7. Maintenance

The CAN-L4-BM Digital Power Monitor is a robust electronic component designed for durability. To ensure its longevity and reliable performance:

• Keep the module clean and free from dust and debris.
• Avoid exposing the module to moisture or extreme temperatures outside its specified operating range (-40~85 °C).
• Inspect all connections periodically for signs of wear or corrosion.
• Do not attempt to repair the internal components unless you are a qualified technician, as this may void any potential warranty.

8. Troubleshooting

The CAN-L4-BM board features LED indicators to help diagnose its status:

If the module does not function as expected, verify all wiring connections, ensure correct parameter settings in your flight controller, and check for proper power supply.

9. Warranty and Support

For technical support, troubleshooting assistance, or warranty inquiries, please contact the manufacturer or your point of purchase. Keep your purchase receipt as proof of purchase.