Bluetooth-connection between Android and Lego Mindstorm NXT

Connecting Your Android Device to Lego Mindstorms NXT

This article guides you through the process of establishing a Bluetooth connection between an Android device and a Lego Mindstorms NXT robot. This connection allows you to control the NXT’s motors, sensors, and program execution from your Android device.

Prerequisites

• Lego Mindstorms NXT robot
• Android device with Bluetooth capability
• NXT-G or other programming software for the NXT (optional)
• Android application for controlling the NXT (e.g., NXT Remote Control, Robot Controller)

Pairing the Devices

Before you can connect to the NXT from your Android device, you need to pair the two devices.

1. Power on your NXT. Make sure the Bluetooth icon is displayed on the NXT brick.
2. Enable Bluetooth on your Android device and go to the Bluetooth settings menu.
3. Scan for nearby devices. Your Android device should discover the NXT, which will usually be named something like “LEGO MINDSTORMS NXT.”
4. Select the NXT from the list of discovered devices and follow the pairing instructions on your screen.
5. Enter the pairing code if prompted. This code is typically “0000” for the NXT.

Controlling the NXT

Once the devices are paired, you can use an Android app to control the NXT robot.

Using NXT Remote Control App

NXT Remote Control is a popular Android application for controlling the NXT.

1. Install the NXT Remote Control app from the Google Play Store.
2. Open the app and select the NXT from the list of paired devices.
3. Control the NXT by using the app’s buttons and sliders to control the motors, sensors, and program execution.

Using a Custom Android Application

If you want to develop your own custom Android application to control the NXT, you’ll need to use the NXT-G programming software or another programming environment to develop your custom programs for the NXT. These programs can then be uploaded to the NXT and controlled from your Android device.

Programming the NXT

You can use NXT-G or other programming environments to create programs for the NXT. Once these programs are uploaded to the NXT, you can control their execution from your Android device.

Example Program using NXT-G

<program name="MyProgram">
  <task name="MainTask">
    <wait for="1000"></wait>
    <motor port="A" power="50"></motor>
    <wait for="1000"></wait>
    <motor port="A" power="0"></motor>
  </task>
</program>

This program will run motor A at 50% power for 1 second, then stop the motor.

Troubleshooting

If you encounter problems connecting your Android device to the NXT, here are some troubleshooting tips:

• Ensure Bluetooth is enabled on both your Android device and the NXT.
• Check if the NXT is discoverable. If it’s not, go to the Bluetooth settings on the NXT and make it discoverable.
• Check the pairing code. It should be “0000” for most NXT robots.
• Try restarting both devices and then attempting the pairing process again.

By following these steps, you should be able to successfully connect your Android device to your Lego Mindstorms NXT robot and enjoy the possibilities of controlling it from your mobile device.

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