CUAV PMU 2 Lite User Manual

PMU 2 Lite

PMU 2 Lite is a high-precision power management module designed for unmanned systems. Its core advantages lie in wide voltage adaptation, high-precision monitoring, and a convenient plug-and-play experience, which can meet the power supply and data monitoring needs of various types of flight controllers.

Features

  • High-Precision Measurement: Voltage accuracy up to ±0.05V and current accuracy up to ±0.1A, enabling real-time capture of power status.
  • Wide Voltage & High Current Support: Supports 20~70V input voltage, with an instantaneous current of up to 220A (for 120 seconds) and a continuous current of 130A (in a well-cooled environment).
  • Temperature Drift Error Resolution: Adopts the ITT3 Temperature Impedance Tracking Algorithm to offset measurement errors caused by temperature changes.
  • Hardware-Software Synergy: Built-in STM32H5 processor runs self-developed M4C architecture software, achieving optimized performance and stability.
  • Factory Pre-Calibration: No manual calibration required for users; it is ready to use out of the box, ensuring consistency and accuracy.
  • CAN Bus Communication Support: Compatible with CAN bus protocol for reliable data transmission.
  • Excellent Heat Dissipation: Features an aviation-grade aluminum alloy housing and thermal silica gel for efficient heat dissipation.
  • Reliable Connection: Equipped with AWG8 cables and QS8 connectors to increase current-carrying wire diameter and significantly reduce heat generation under load.

Hardware Specifications

Parameter NameSpecifications
ProcessorSTM32H5 Arm® Cortex®-M33, 250 MHz
Input Voltage5V version: 12V ~ 70V
15V version: 20V ~ 70V
Instantaneous Current220A@120Sec
Continuous Current130A (in a well-cooled environment)
Detection Current Range0A ~ 220A
Voltage Accuracy±0.05V
Current Accuracy±0.1A
Voltage Output15V version: 15V 6A
5V version: 5.2V 7A
Communication ProtocolCAN
Calibration SettingFactory pre-calibrated, no user calibration required
Operating FirmwareCUAV M4C PMU2
Power InterfaceAWG8 / QS8
Data Interface15V version: MOLEX 5055670871
5V version: MOLEX 5025850670
Dimensions57.25 × 32.25 × 17.5 mm (excluding cables)
Weight222g (including cables)
Operating Temperature-20℃ ~ +80℃

Size

Hardware Connection

15V Version Connected to X25 EVO

X25 EVO has PMU 2 Lite settings enabled by default. No parameter configuration is required. it supports plug-and-play.

5V Version Connected to Pixhawk V6X/X7 Series Controllers

X25 EVO has PMU 2 Lite settings enabled by default. No parameter configuration is required .it supports plug-and-play.

Connection to Other Controllers

Connect CAN_H and CAN_L of the CAN bus to the CAN interface. Insert the red and black power cables into the VCC/GND pins of the Power port respectively. The power module can be configured graphically via the LGC ground station.

Pinouts

View Power Information

PMU 2Lite Configuration Guide (ArduPilot)

This chapter applies to scenarios where PMU 2Lite is used with the ArduPilot stack (controllers running ArduPilot firmware).

Tip

Under normal circumstances, the PMU 2lite is plug-and-play. No configuration mentioned in this chapter is required. Only hardware connections are required.

Enabling PMU 2Lite

To enable voltage and current detection, you need to configure the controller parameters related to PMU 2Lite. Connect the controller to the MissionPlanner ground station, set the following parameters in the Full Parameter List, and restart the controller after writing the parameters:

				
					CAN_P1_DRIVER set to 1
CAN_P2_DRIVER set to 1
BATT1_MONITOR set to 8
				
			

Tip

For ArduPilot firmware versions below 4.6, set BATT_MONITOR to 8.

Viewing Power Information

Custom Configuration

PMU 2Lite provides 7 parameters for users to customize:

				
					- BATTERY_ID // Battery ID, Invalid
- CAN_NODE_ID // CAN Node ID
- CELL_SERIES_NUM // Number of battery cells, default value is 0 (automatic recognition), used to estimate battery percentage.
- CELL_FULL_VOLTAGE // Full voltage of a single cell, used to estimate battery percentage.
- CELL_EMPTY_VOLTAGE // Empty voltage of a single cell, used to estimate battery percentage.
- CALIBRATION_PARAM // Calibration status identifier; a value of 1 indicates calibrated (read-only, cannot be written).
- USE_TMP112 // Temperature sensor, default value is 1 (enabled); set to 0 to disable.
				
			

Note

Under normal circumstances, the default parameters can meet the needs of most users. Do not modify them unless necessary.

Modifying Parameters

  1. Connect the controller to the MissionPlanner ground station.
  2. Navigate to the Configuration > Optional Hardware > Dronecan/UAVCAN Setup interface.
  3. Click “mavlink-can1” and locate the PMU 2Lite Information section.
  1. Find and set the parameters to be modified, save them, then restart the controller.

High Voltage (HV) Battery Cell Setup

The PMU 2Lite system is configured for a standard lithium battery voltage platform (4.25V when fully charged). For high-voltage battery platforms (4.35V/4.45V), the PMU 2Lite system parameters must be modified for more accurate power measurement.

Take a 6S battery pack (where the full voltage of a single cell is 4.35V and the empty voltage is 3.3V) as an example. Set the following parameters in the PMU 2Lite parameter list:

				
					CELL_SERIES_NUM = 6
CELL_FULL_VOLTAGE = 4350
CELL_EMPTY_VOLTAGE = 3300
				
			

PMU 2Lite Configuration Guide (PX4)

This chapter applies to scenarios where PMU 2Lite is used with the PX4 flight stack (controllers running PX4 firmware).

Tip

Under normal circumstances, the PMU 2lite is plug-and-play. No configuration mentioned in this chapter is required. Only hardware connections are required.

Enabling Voltage and Current Detection

To enable voltage and current detection, you need to configure the controller parameters. Connect the controller to the QGroundControl (QGC) ground station, set the following parameters in the Full Parameter List, and restart the controller after writing the parameters:

				
					UAVCAN_ENABLE set to "Sensor Automatic Config" (Sensor Auto Configuration)
UAVCAN_SUB_BAT set to "Raw data" (Raw Data)
				
			

Viewing Power Information

Custom Configuration

PMU 2Lite provides 7 parameters for users to customize:

				
					BATTERY_ID // Battery ID, Invalid
CAN_NODE_ID // CAN Node ID
CELL_SERIES_NUM // Number of battery cells, default is 0 (automatic recognition), used to estimate battery percentage.
CELL_FULL_VOLTAGE // Full voltage of a single cell, used to estimate battery percentage.
CELL_EMPTY_VOLTAGE // Empty voltage of a single cell, used to estimate battery percentage.
CALIBRATION_PARAM // Calibration status identifier; a value of 1 indicates calibrated (read-only, cannot be written).
USE_TMP112 // Temperature sensor, default is 1 (enabled); set to 0 to disable.
				
			

Note

Under normal circumstances, the default parameters can meet the needs of most users. Do not modify them unless necessary.

Modifying Parameters

Connect the controller to the QGroundControl (QGC) ground station, open the Analyze Tools (Analysis Tools) > MAVLink Console interface, and send the following commands for configuration:

				
					uavcan status // Obtain the NODE ID of PMU 2Lite (press the "Enter" key to send the command)
uavcan param list + [ID] // Read PMU 2Lite parameter information
uavcan param set + [ID] + [Parameter Name] + [Value] // Set (modify) PMU 2Lite parameter values
uavcan param save + [ID] // Save PMU 2Lite parameter configuration
				
			

High Voltage (HV) Battery Cell Setup

The PMU 2Lite system is configured for a standard lithium battery voltage platform (4.25V when fully charged). For high-voltage battery platforms (4.35V/4.45V), the PMU 2Lite system parameters must be modified for more accurate power measurement.

Take a 6S battery pack (where the full voltage of a single cell is 4.35V and the empty voltage is 3.3V) with a PMU 2Lite node ID of 49 as an example. Send the following commands in the MAVLink Console interface:

				
					uavcan param set 49 CELL_SERIES_NUM=6
uavcan param set 49 CELL_FULL_VOLTAGE=4350
uavcan param set 49 CELL_EMPTY_VOLTAGE=3300
uavcan param save 49
				
			

Note

If a save failure is prompted, restart the device and re-read the PMU 2Lite configuration information to check if the modification was successful.

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