How to Use BLS 35A Mini V2 4-in-1 ESC: Examples, Pinouts, and Specs

The BLS 35A Mini V2 4-in-1 ESC by SpeedyBee (Part ID: ESC) is a compact and efficient electronic speed controller designed specifically for multirotor drones. This component integrates four ESCs into a single unit, significantly simplifying wiring, reducing weight, and improving overall build efficiency. It is capable of handling up to 35A of continuous current per channel, making it suitable for high-performance drone applications. The ESC supports smooth motor control, a wide range of motor types, and advanced protocols for enhanced responsiveness.

• Multirotor drones (e.g., quadcopters, hexacopters)
• FPV (First-Person View) racing drones
• Aerial photography and videography platforms
• Lightweight and compact drone builds
• Hobbyist and professional drone projects

The following table outlines the key technical details of the BLS 35A Mini V2 4-in-1 ESC:

The BLS 35A Mini V2 4-in-1 ESC features a compact pinout for easy integration into drone builds. Below is the pin configuration:

1. Power Connection: Connect the VBAT pin to the positive terminal of your LiPo battery and the GND pin to the negative terminal.
2. Motor Connections: Solder the motor wires to the corresponding motor output pads (M1, M2, M3, M4).
3. Signal Connections: Connect the signal input pins (Signal 1–4) to the flight controller's motor output pins.
4. Telemetry (Optional): If your flight controller supports telemetry, connect the telemetry pin to the appropriate input on the flight controller.
5. Mounting: Secure the ESC to your drone frame using M3 screws and ensure proper insulation to avoid short circuits.

• Cooling: Ensure adequate airflow over the ESC to prevent overheating during operation.
• Firmware Updates: Use BLHeli_S software to update the firmware and configure settings such as motor direction and protocol.
• Voltage Compatibility: Verify that your LiPo battery voltage is within the supported range (2S–6S).
• Signal Protocol: Configure your flight controller to use a compatible protocol (e.g., DShot600) for optimal performance.
• Soldering: Use high-quality solder and ensure clean, secure connections to avoid electrical issues.

While the BLS 35A Mini V2 4-in-1 ESC is typically controlled by a flight controller, you can simulate signal output using an Arduino UNO for testing purposes. Below is an example code snippet:

#include <Servo.h>

// Create servo objects for each motor
Servo motor1;
Servo motor2;
Servo motor3;
Servo motor4;

void setup() {
  // Attach ESC signal pins to Arduino PWM pins
  motor1.attach(9);  // Motor 1 signal connected to pin 9
  motor2.attach(10); // Motor 2 signal connected to pin 10
  motor3.attach(11); // Motor 3 signal connected to pin 11
  motor4.attach(6);  // Motor 4 signal connected to pin 6

  // Initialize ESCs with a low throttle signal
  motor1.writeMicroseconds(1000); // Minimum throttle
  motor2.writeMicroseconds(1000);
  motor3.writeMicroseconds(1000);
  motor4.writeMicroseconds(1000);

  delay(5000); // Wait for ESCs to initialize
}

void loop() {
  // Example: Gradually increase throttle
  for (int throttle = 1000; throttle <= 2000; throttle += 10) {
    motor1.writeMicroseconds(throttle);
    motor2.writeMicroseconds(throttle);
    motor3.writeMicroseconds(throttle);
    motor4.writeMicroseconds(throttle);
    delay(50); // Wait 50ms between throttle steps
  }

  delay(2000); // Hold maximum throttle for 2 seconds

  // Gradually decrease throttle
  for (int throttle = 2000; throttle >= 1000; throttle -= 10) {
    motor1.writeMicroseconds(throttle);
    motor2.writeMicroseconds(throttle);
    motor3.writeMicroseconds(throttle);
    motor4.writeMicroseconds(throttle);
    delay(50);
  }

  delay(2000); // Hold minimum throttle for 2 seconds
}

1. ESC Not Powering On

   • Cause: Incorrect power connection or insufficient battery voltage.
   • Solution: Verify that the VBAT and GND pins are correctly connected to the battery and that the battery voltage is within the supported range (2S–6S).

2. Motors Not Spinning

   • Cause: Signal wires not connected or incorrect protocol configuration.
   • Solution: Check the signal connections between the ESC and flight controller. Ensure the flight controller is configured to use a compatible protocol (e.g., DShot600).

3. Overheating

   • Cause: Insufficient cooling or excessive current draw.
   • Solution: Ensure proper airflow over the ESC and verify that the motors and propellers are not overloading the ESC.

4. Motor Stuttering or Jittering

   • Cause: Incorrect motor timing or damaged motor/ESC.
   • Solution: Update the ESC firmware using BLHeli_S and check for physical damage to the motors or ESC.

• Q: Can I use this ESC with a 7S LiPo battery?
  A: No, the ESC supports a maximum of 6S (25.2V). Using a 7S battery may damage the ESC.

• Q: Does this ESC have a built-in BEC?
  A: No, the ESC does not include a BEC. You will need an external BEC or a flight controller with a built-in BEC to power other components.

• Q: How do I reverse motor direction?
  A: Use the BLHeli_S software to configure the motor direction for each channel.

• Q: Is this ESC waterproof?
  A: No, the ESC is not waterproof. Apply conformal coating if you plan to use it in wet conditions.