16. System Integration

The Motor Driver

First Step “Test”

🛸 Control a Coreless Motor with MX1508 + XIAO RP2040 + 3.7V LiPo

This guide explains how to control a coreless motor (6x15mm) using the MX1508 motor driver, a XIAO RP2040, and a 3.7V 1800mAh LiPo battery.

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✅ Components

Component	Specs / Notes
Motor	6×15mm coreless, ~3.7V, ~70,000 RPM
Motor Driver	MX1508 Dual H-Bridge
Microcontroller	XIAO RP2040 (3.3V logic)
Battery	3.7V 1800mAh LiPo

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⚠️ Compatibility Check

Feature	Status ✅ / ⚠️	Notes
MX1508 input voltage	✅	2V–10V, OK with 3.7V LiPo
Motor voltage	✅	Suitable for 3.7V
Logic level (PWM from RP2040)	✅	MX1508 works with 3.3V signals
Motor current vs MX1508	⚠️	Ensure draw < 1.5A per channel (typical OK)

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🔌 Wiring Diagram

[LiPo 3.7V +] -----> MX1508 VCC  
[LiPo GND] ---------> MX1508 GND and XIAO GND

XIAO D6 (PWM) ------> MX1508 IN1  
XIAO D7 (PWM) ------> MX1508 IN2

MX1508 OUT1 --------> Motor +  
MX1508 OUT2 --------> Motor -

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🧠 Arduino Code Example

Make sure to install XIAO RP2040 support in the Arduino IDE.

int motorPin1 = 6; // IN1
int motorPin2 = 7; // IN2

void setup() {
  pinMode(motorPin1, OUTPUT);
  pinMode(motorPin2, OUTPUT);
}

void loop() {
  // Forward rotation
  analogWrite(motorPin1, 150);  // Speed (0–255)
  analogWrite(motorPin2, 0);
  delay(2000);

  // Stop
  analogWrite(motorPin1, 0);
  analogWrite(motorPin2, 0);
  delay(1000);

  // Backward rotation
  analogWrite(motorPin1, 0);
  analogWrite(motorPin2, 150);
  delay(2000);
}

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🔋 Battery Notes

• Battery: 3.7V 1800mAh LiPo
• Typical C-rating: ~20C (estimate)
• Max Current Output:
  [ 1.8A × 20C = 36A peak (enough for multiple motors) ]
• Protect battery: Don’t discharge below 3.3V

Optional: - Add a voltage divider for monitoring battery level via XIAO - Or use a LiPo buzzer for low voltage alarm

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✅ Steps Summary

1. Connect battery to MX1508 VCC and GND.
2. Connect XIAO GND to MX1508 GND.
3. Connect PWM pins from XIAO to IN1, IN2 of MX1508.
4. Connect motor to OUT1 and OUT2.
5. Upload Arduino code to control direction and speed.
6. Power up and test!

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The Flight Controller Board