09 - Bluetooth Remote Control Car
Introduction
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The Grapebit board, known for its cost-effectiveness as a programming controller, is often used in lightweight projects. For remote control projects, it usually requires an additional Grapebit or Future Board for ESP-NOW broadcasting, which adds to the project’s overall cost.
This project aims to reduce costs for Grapebit remote control projects by connecting a commonly available Bluetooth controller to the Grapebit board for remote control.
Materials Needed
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- Grapebit
- Geekservo 9g Red Motor x2
- Bluetooth Controller
- Kittenbot Lithium Battery Pack
- LEGO blocks (frame beams, wheels, omni wheels)
Bluetooth Controller
We’ve chosen a standard Bluetooth controller available on the market, featuring 14 programmable buttons (the home button is not usable).
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Bluetooth Car Project
To help users get started and understand how to use the Grapebit and Bluetooth controller, we’ll build a remote-controlled car.
The Grapebit can drive two motors in one direction each. It will pair directly with the Bluetooth controller, and upon receiving button commands, the Grapebit will respond accordingly.
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Wiring
You can assemble a simple two-wheeled car according to your preference. Connect the two motors to the Grapebit board, and attach the Kittenbot lithium battery pack for power.
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Quick Programming
Update Plugins and Firmware
Connect the Grapebit to your computer via USB.
Ensure the Grapebit hardware plugin is updated to v2.1.0 or higher. (If not updated, a green upgrade icon will be displayed) 
Set the Grapebit into firmware recovery mode by holding down the B button and pressing the Reset button, then click "Restore Firmware" to update to the latest firmware (only needs to be done once).
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Reconnect the Grapebit.
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Load the Bluetooth controller plugin.
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Write and upload the program for controlling the Grapebit’s LED with the Bluetooth controller.
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Turn on the Bluetooth controller and wait for the Grapebit to pair automatically (usually within 10 seconds). If pairing fails, press the Reset button on the Grapebit to retry.
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Test the connection.
According to the program logic, press the up and down buttons on the controller to turn the Grapebit’s LED on and off.
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Bluetooth Car
Assembly
Assemble a two-wheeled car to your liking.
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Car Program
Modify the program to include motor movement. Note that the Grapebit’s two motor drives only support one-way rotation.
If the motor behavior does not match the program, try reversing the motor wires or swapping M1 and M2 motor connections.
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Download
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Final Result
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