Getting Started

The Maqueen Plus V3 is available in two versions: the AA battery version and the 18650 lithium battery version. These two versions differ only in their power supply methods, while all other features and functionalities remain identical.

1 Usage methods and safety precautions of AA batteries

1.1 The AA batteries supported by Maqueen Plus V3

If you purchase the AA battery version of Maqueen Plus, it supports two specifications: 1.5V AA batteries and 1.2V nickel-metal hydride rechargeable AA batteries. When purchasing batteries, please be careful not to buy AAA batteries. AA batteries can be purchased in most supermarkets. It should be noted that 1.5V alkaline batteries are disposable batteries and cannot be charged. Otherwise, explosion or fire may occur.

2. POWER SWITCH

1. For the safety of use, Maqueen Plus is equipped with two power switches. They are respectively located on the battery board and the bottom plate of the car. It can operate normally only after both switches are turned on. As shown in the picture:

3 Installation methods of the battery board and the metal bracket

Maqueen Plus V3 in order to give students a certain assembly experience, the battery board and the metal bracket were not installed during production.

The specific installation methods are as follows:

3.1 Tool Preparation

• Screwdriver *1
• 35mm copper column *5
• Metal adjustment bracket *1
• Installation screw *5
• Sensor installation bracket *1
• Hand-twisted screw *4
• Battery board *1
• Power connection line *1
• Laser ranging sensor *1

3.2 Install the battery board

1. Install the 35mm supporting copper columns, which need to be screwed in place to ensure the flatness of the battery board after installation. Due to the differences in the thread manufacturing process, some copper columns may not be easily screwed in place. At this time, please use pliers to assist in the installation appropriately. But do not install it violently to avoid damaging the thread. The installation position is as shown in the picture:

   

2. Use screws to install the battery board on the copper columns, as shown in the picture:

   

3. Install the connection line, as shown in the picture:

   

3.3 Install the metal bracket and the laser ranging sensor

1. Install two 35mm copper columns at the position as shown in the picture:

   

2. Use hand-twisted screws to install the adjustment bracket on the battery board. Please note that the front and rear directions of the bracket in the picture should not be installed wrongly, otherwise it will block the USB interface of the micro:bit, as shown in the picture:

   

3. Use hand-twisted screws to install the sensor fixing bracket, as shown in the picture:

   

4. Install the sensor, as shown in the picture:

   

3.4 The form after installation is completed

4. Motor replacement method

Maqueen Plus V3 adopts a design with replaceable motors. If the motors are damaged due to high-intensity use or being dropped, they can be replaced in the following way.

4.1 Remove the motor

1. Turn off the power of Maqueen Plus V3.

2. Pull out the two wheels.

3. Pull out the connection lines on the motor. As shown in the picture:

   

4. Use a screwdriver to unscrew the 4 motor screws at the bottom. As shown in the picture:

   

The motor disassembly is completed.

4.2 Install the motor

1. Install the buckle on the motor, as shown in the picture:

   

2. Install the motor on the base plate, as shown in the picture:

   

3. Install the connection line. This position is not very easy to install and requires some patience, as shown in the picture:

   

4. Install the wheels. When installing the wheels, pay attention to align the plane of the motor shaft with the plane of the wheels to avoid failure to install or damage to the wheel shaft hole. As shown in the picture:

   

5. Calibration method of the line-tracking sensor

The line-tracking sensor has been calibrated before leaving the factory. Usually, you don't need to calibrate it. If it is found that the line-tracking sensor cannot correctly recognize the black line, you can try to calibrate the line-tracking. The method is as follows:

1. Place the 5 probes of the line-tracking sensor on the black area at the same time. (Make sure that all 5 probes are in the black area)
2. Turn on the power of Maqueen Plus.
3. Press and hold the "Calc-Key" button for about 2 seconds. The line-tracking indicator light starts to flash, and then release the button. The calibration is completed.
4. Check the calibration result: Put the line-tracking sensor on the white background, the line-tracking indicator light goes out. Put it on the black background, the line-tracking indicator light is on. The calibration is correct.

The line-tracking sensor uses the grayscale detection method to recognize the black line. Therefore, not all black lines can be effectively recognized. For materials that cannot be recognized, even if calibrated, they cannot be correctly recognized. For example, laser-printed maps may not be recognized.

6. Example tutorial based on MakeCode programming

6.1 Open the MakeCode platform and load the library

Click the link to enter the MakeCode graphical programming platform: https://makecode.micro:bit.org/

Click "New Project" to create a new project, as shown in the picture:

In the pop-up dialog box, give a name to the project and then click "Create", as shown in the picture:

Load the Maqueen Plus library:

Click the "Settings icon" and then click "Extensions", as shown in the picture:

Load the Maqueen Plus library: Search for dfrrobot in Extensions, and then select

"DFRobot_MaqueenPlus_V2", as shown in the following picture:

Note: Maqueen Plus V3 and Maqueen Plus V2 use the same library. To ensure that the link does not change, the name of the library is still V2, but all the functions of V3 have been integrated.

The loading of the library is completed. The loaded library is shown in the picture. It will contain the libraries of both the infrared and the matrix laser ranging sensors at the same time.

Safety Precautions

Since Maqueen Plus is a STEM education product and is presented in a bare - board form, the following safety precautions should be noted during use:

1. The use of batteries must strictly comply with the battery usage methods and safety precautions. Otherwise, it may damage the product and cause risks such as overheating and combustion.
2. Do not touch the product, especially the circuit board part and the battery part, with sharp objects like screwdrivers. This is to avoid damaging components or causing danger.
3. Do not touch the product's circuit board with metal objects to prevent short - circuits, which can damage the product and lead to risks such as overheating and combustion.
4. The product is not waterproof and should not come into contact with liquid substances such as water and beverages. If liquid is accidentally spilled on the product, immediately turn off the power and remove the battery. Only attempt to power it on after the moisture has completely dried.
5. When storing the product, do not stack multiple products together to avoid component damage, and even the risk of power short - circuits, which may cause fires and personal injury.