Mini903 Hardware Setup: Guide To Connections & Specs

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Mini903 Hardware Setup: Guide to Connections & Specs

Alright, guys! Let's dive into setting up the hardware for the Mini903 Capstone project. This guide will walk you through the specs and connections for each component, making sure you get everything hooked up correctly. We'll cover the motor driver, flight controller, Raspberry Pi, and battery pack.

Common Setup

Before we get into the specifics, there are a few things that are common to all components. First, safety first! Make sure to follow the proper safety procedures when working with electricity. Now, let's connect everything:

Power Distribution

First, let's set up the power distribution. Understanding the power setup is crucial for ensuring a stable and reliable system. You'll need to connect the battery pack to the system using a specific sequence of components to manage power effectively and protect your hardware. Here's the standard configuration:

  1. Battery Pack (IYP-24V10Ah-A3): This is your main power source. Ensure it is fully charged before starting any tests. A fully charged battery guarantees that all components receive the necessary voltage and current, preventing unexpected shutdowns or malfunctions during operation.
  2. Fuse: Connect the battery pack to a fuse. The fuse is a critical safety component that protects the entire system from overcurrent. If there is a surge or short circuit, the fuse will blow, preventing damage to the more expensive components like the motor driver, DC-DC converter, and power module. Use a fuse with an appropriate amperage rating for your system to ensure it trips when necessary but doesn't cause nuisance tripping during normal operation.
  3. Power Switch: After the fuse, connect a power switch. This allows you to easily turn the entire system on and off. A well-placed and easily accessible power switch is essential for quick shutdowns in case of emergencies or when performing maintenance. Ensure the switch is rated for the voltage and current of your battery pack to prevent switch failure or arcing.
  4. Distribution to Components: From the power switch, distribute power to the following components:
    • MDDS60 Motor Driver: This controls the DC motor.
    • DC-DC Converter: Converts the 24V from the battery to 5V for the Raspberry Pi and servo motor.
    • Power Module: Supplies power to the Pixhawk.

Power Module to Pixhawk Connection

  • Connect the Power Module to the Pixhawk POWER IN port. This connection provides the Pixhawk with the necessary power to operate its flight control functions.

DC-DC Converter to Raspberry Pi Connection

  • Use a DC-DC converter to step down the 24V from the battery to 5V. A DC-DC converter is essential because the Raspberry Pi requires a 5V power supply, and directly connecting it to the 24V battery would damage it.
  • Connect the DC-DC (5V 3~5A) output to the PI 5V PIN2. This pin provides the main 5V power supply to the Raspberry Pi.
  • Connect the DC-DC GND to the PI GND (PIN 9). Grounding is crucial for completing the circuit and ensuring stable operation.

Additional Notes on DC-DC Converter

  • Ensure you use a 24V to 5V DC-DC converter. This type of converter is specifically designed to step down the voltage from a 24V source to the 5V required by the Raspberry Pi and servo motor.

Power Switch to MDDS60 Motor Driver Connection

  • Connect the Power Switch to the MDDS60 V+ (24V). This provides the motor driver with the main power supply.
  • Connect the Power Switch to the MDDS60 V- (GND). Grounding is essential for the motor driver to function correctly.

Raspberry Pi to Pixhawk Telemetry Connection

Setting up telemetry between the Raspberry Pi and Pixhawk is crucial for enabling advanced functionalities such as autonomous navigation, data logging, and real-time monitoring. This connection allows the Raspberry Pi to send commands to the Pixhawk and receive telemetry data, enabling sophisticated control and analysis.

Wiring Instructions

To establish the telemetry connection, you will need to connect the GPIO pins on the Raspberry Pi to the corresponding TELEM2 pins on the Pixhawk. Here’s a detailed guide to ensure the connection is set up correctly:

  1. PI GPIO 14 (TX) PIN8 to Pixhawk TELEM2 RX (3):
    • Connect the transmit (TX) pin on the Raspberry Pi to the receive (RX) pin on the Pixhawk. This connection allows the Raspberry Pi to send data to the Pixhawk.
    • Use a reliable wire and ensure it is securely connected to both pins. A loose connection can cause data transmission errors and instability.
  2. PI GPIO 15 (RX) PIN10 to Pixhawk TELEM2 TX (2):
    • Connect the receive (RX) pin on the Raspberry Pi to the transmit (TX) pin on the Pixhawk. This connection allows the Pixhawk to send data back to the Raspberry Pi.
    • Double-check the connection to ensure the TX and RX pins are correctly aligned, as reversing them will prevent communication.
  3. PI GND PIN9 to Pixhawk TELEM2 GND (6):
    • Connect the ground (GND) pin on the Raspberry Pi to the ground pin on the Pixhawk. This provides a common ground reference for the communication, ensuring a stable and reliable signal.
    • A solid ground connection is essential for reducing noise and preventing communication errors.

Servo Motor Connection

To control the steering servo motor, you'll need to connect it to both the Raspberry Pi and a DC-DC converter. The Raspberry Pi provides the control signal, while the DC-DC converter provides the necessary power. Here’s how to connect everything properly:

Wiring Instructions

  1. PI GPIO 23 PIN 16 to Steering Servo Motor Signal (Orange/Yellow/White):
    • Connect the GPIO 23 pin on the Raspberry Pi to the signal wire of the servo motor. This pin will send the PWM (Pulse Width Modulation) signal that controls the servo’s position. The signal wire is typically orange, yellow, or white, depending on the servo motor manufacturer.
    • Ensure the connection is secure to avoid signal interruptions that can cause erratic servo behavior.
  2. DC-DC 5V BEC to Steering Servo Motor +5V Power (Red):
    • Connect the +5V output from the DC-DC converter to the +5V power wire of the servo motor. This provides the necessary power for the servo to operate. The power wire is usually red.
    • Use a reliable power source capable of delivering the required current for the servo motor to prevent voltage drops and ensure smooth operation.
  3. DC-DC GND to Steering Servo Motor GND (Brown/Black):
    • Connect the ground (GND) from the DC-DC converter to the ground wire of the servo motor. This completes the circuit and provides a common ground reference.
    • The ground wire is typically brown or black. Ensure a solid ground connection to minimize noise and prevent operational issues.

DC-DC Converter Specifications

  • DC to DC Converter: Use a 24V to 5V DC-DC converter to step down the voltage from the battery to the required 5V for the servo motor.

Power Considerations

  • Combined Power for Pi and Servo: If you plan to power both the Raspberry Pi and the servo motor from the same DC-DC converter, ensure that the converter can supply sufficient current. A 5V 4A~5A or higher converter should be adequate for this setup.

MDDS60 Motor Driver Connection

The MDDS60 motor driver is used to control the DC motor. Here’s how to connect it:

Pixhawk to MDDS60 Connection

  1. Pixhawk MAIN OUT CH1 S to MDDS60 RC1 Ω (Signal):
    • Connect the signal output from the Pixhawk (typically MAIN OUT CH1) to the RC1 signal input on the MDDS60 motor driver. This connection sends the control signal from the flight controller to the motor driver.
    • Ensure the connection is secure and properly insulated to prevent signal interference.
  2. Pixhawk MAIN OUT CH1 - to MDDS60 RC1 - (GND):
    • Connect the ground from the Pixhawk (typically MAIN OUT CH1) to the ground input on the MDDS60 motor driver. This provides a common ground reference for the control signal.
    • A solid ground connection is crucial for reliable signal transmission.

MDDS60 to DC Motor Connection

  1. MDDS60 MOTOR 1 A to DC Motor +:
    • Connect the MOTOR 1 A output from the MDDS60 to the positive (+) terminal of the DC motor. This connection provides the forward current to the motor.
    • Use appropriately sized wires to handle the motor current and ensure a secure connection.
  2. MDDS60 MOTOR 1 B to DC Motor -:
    • Connect the MOTOR 1 B output from the MDDS60 to the negative (-) terminal of the DC motor. This connection provides the return path for the current.
    • Ensure the wire gauge is sufficient to handle the current and that the connection is secure.

Polarity Note

  • DC Motor Polarity: DC motors do not have a fixed polarity. If the motor runs in the wrong direction during testing, simply reverse the connections of MOTOR 1 A and MOTOR 1 B.

Coding Considerations

When you get to the coding stage, keep these points in mind:

  • SERVO1_FUNCTION = 70: Use this parameter to set the function of SERVO1 to throttle, which allows you to control the motor's output.

Conclusion

By following these steps, you should have a solid foundation for your Mini903 Capstone project. Remember to double-check all connections and power considerations to ensure a safe and functional setup. Good luck, and have fun building!