How to Use Solar Power Manager 3.3/5/9/12V: Examples, Pinouts, and Specs

The Solar Power Manager 3.3/5/9/12V by DFRobot (Part ID: MPPT) is a versatile power management module designed to efficiently regulate and distribute solar energy. It supports multiple output voltages (3.3V, 5V, 9V, and 12V), making it suitable for a wide range of electronic applications. This module integrates Maximum Power Point Tracking (MPPT) technology to optimize solar energy harvesting, ensuring maximum efficiency.

• Powering IoT devices and sensors in remote locations
• Solar-powered battery charging systems
• Renewable energy projects and prototypes
• Portable solar energy solutions for outdoor electronics
• Educational projects involving solar energy and power management

The following table outlines the key technical details of the Solar Power Manager:

The module features multiple input/output pins and connectors. The table below provides details:

1. Connect the Solar Panel or DC Input:

   • Attach a solar panel (6V to 24V) to the VIN pin or connector.
   • Alternatively, connect a DC power source within the same voltage range.

2. Connect a Battery (Optional):

   • Attach a single-cell Li-ion/LiPo battery to the BAT pin for charging and energy storage.

3. Select the Desired Output Voltage:

   • Use the 3.3V, 5V, 9V, or 12V output pins to power your devices.
   • Ensure the connected load does not exceed the maximum current rating for the selected output.

4. Enable the Module:

   • Use the EN pin to enable or disable the module. Pull the pin high to enable the outputs.

5. Monitor the Charging Status:

   • Use the STAT pin to monitor the battery charging status. A low signal indicates charging, while a high signal indicates the battery is fully charged.

• MPPT Optimization: Ensure the solar panel operates within its optimal voltage and current range for maximum efficiency.
• Battery Protection: Use a compatible single-cell Li-ion/LiPo battery with built-in protection circuitry to prevent overcharging or deep discharge.
• Heat Dissipation: Avoid placing the module in enclosed spaces without ventilation, as it may generate heat during operation.
• Load Current: Do not exceed the maximum current rating for each output voltage to prevent damage to the module.

The Solar Power Manager can be used to power an Arduino UNO via its 5V output. Below is an example setup and code:

1. Connect the 5V output of the Solar Power Manager to the 5V pin of the Arduino UNO.
2. Connect the GND pin of the Solar Power Manager to the GND pin of the Arduino UNO.
3. Optionally, connect a solar panel and battery to the module for a complete solar-powered system.

// Example code to read a sensor and send data via serial
// Powered by the Solar Power Manager 5V output

const int sensorPin = A0; // Analog pin connected to the sensor
int sensorValue = 0;      // Variable to store the sensor reading

void setup() {
  Serial.begin(9600); // Initialize serial communication at 9600 baud
  pinMode(sensorPin, INPUT); // Set the sensor pin as input
}

void loop() {
  sensorValue = analogRead(sensorPin); // Read the sensor value
  Serial.print("Sensor Value: ");      // Print label to serial monitor
  Serial.println(sensorValue);         // Print the sensor value
  delay(1000);                         // Wait for 1 second before next reading
}

1. No Output Voltage:

   • Cause: The EN pin is not pulled high.
   • Solution: Ensure the EN pin is connected to a high signal to enable the module.

2. Battery Not Charging:

   • Cause: Incompatible or faulty battery.
   • Solution: Verify the battery is a single-cell Li-ion/LiPo type and is functioning properly.

3. Overheating:

   • Cause: Excessive load or poor ventilation.
   • Solution: Reduce the load current or improve ventilation around the module.

4. Low Efficiency:

   • Cause: Solar panel not operating at its optimal point.
   • Solution: Use a solar panel with a voltage and current rating suitable for the module's MPPT range.

• Can I use this module without a battery? Yes, the module can operate directly from a solar panel or DC input without a battery.

• What happens if the input voltage exceeds 24V? The module may be damaged. Always ensure the input voltage stays within the specified range.

• Can I adjust the battery charging current? Yes, the charging current can be adjusted by replacing the onboard resistor. Refer to the DFRobot datasheet for details.

• Is the module compatible with other microcontrollers? Yes, the module can power any microcontroller that operates within the supported output voltages.