WiFi camera control

The WiFi camera module in this case needs to be purchased separately

1. Learning objectives

In this course, we mainly learn how to use MakeCode graphical programming to achieve WiFi remote control of Proficient carrier.

2. Building blocks

For detailed steps of building blocks, please refer to the installation drawings of [Assembly Course]--[Proficient carrier] in the materials or the building block installation brochure.

Then install the WiFi camera module according to the following steps:

3. Wiring

Motor wiring

Insert the motor wiring on the left side of the car into the M1 interface of the Super:bit expansion board, and the black wire is close to the battery side;

Insert the motor wiring on the right side of the car into the M3 interface of the Super:bit expansion board, and the black wire is close to the battery side;

Insert the building block servo wiring into the S1 interface of the Super:bit expansion board, and insert the orange servo wiring into the yellow pin of S1.

As shown in the figure below:

! Notes:

When taking a course related to the building block servo for the first time, we need to remove the large gear installed on the servo and upload the program of this course to the micro:bit; then turn on the power switch of the Super:bit expansion board and wait for the building block servo to turn to the initial position; then, we can turn off the power, adjust the angle of the car's projection rod to be parallel to the ground, and then install the servo gear. (If you have used the catapult and servo-related programs before, you can skip this step)

Wiring of the camera and the car

4. Programming

Method 1 Online programming:

First, connect the micro:bit to the computer via a USB data cable, and a U disk will pop up on the computer. Click the URL in the U disk: https://makecode.microbit.org/ to enter the programming interface. Then, add the Yahboom software package to program.

Method 2 Offline Programming:

Open the offline programming software MakeCode and enter the programming interface. Click [New] and add the Yahboom software package to start programming.

superbit kit expansion package: https://github.com/YahboomTechnology/SuperBitLibV2 WiFi camera expansion package: https://github.com/yahboomtechnology/ESP32-wifi-Microbit

4.1 Add expansion package

4.2 Building blocks used

The location of the building blocks required for this programming is shown in the figure below.

4.3 Introduction to main building blocks

• Serial port initialization building block This is used to define the pins for serial communication, and communicate with the WiFi camera. The baud rate is 115200 by default and cannot be changed
• Set the size of the serial port receiving buffer This building block is used to define the size of a packet of data that can be accepted for transparent transmission, for example This defines that the maximum size of a packet is 30 characters. Exceeding this will result in incomplete data reception. This value cannot be less than 25, otherwise the IP information will also be incomplete
• Block for obtaining transparent data This block is mainly used to obtain information sent by the host computer to microbit, and transmits information through the wifi camera as the intermediate information
• Block for car control This block is mainly used to receive instructions sent by the app and transmit them to the car
• You can know the function of other blocks by looking at their names. For how to use them, you can refer to the source code provided in this tutorial. This tutorial will not elaborate on them

4.4 Combined blocks

You can also directly open the microbit-wifi_superkit_AP.hex file provided in this experiment and drag it into the browser that opens the URL, and the program diagram of the source code of this project will be automatically opened

5. Experimental phenomenon

1. After powering on, wait until the microbit screen no longer displays anything before you can control the connection with the app. At first, the display will be a heart icon. After successful startup, its firmware version number will be displayed. After waiting for a check icon to be displayed, the default IP address of the hotspot AP mode "ap_ip:192.168.4.1" will be displayed. (This tutorial recommends using a simple self-heating hotspot AP mode for connection. To connect to WIFI using STA mode, see the expanded content of STA mode connection below)

2. Download the APP: For Android, please use the browser to scan the following QR code to download and install YahboomCam. For Apple, please use the camera to scan the QR code to enter the App Store to download and install, or search for "YahboomCam" in the App Store to find "YahboomCam".

3. Use your mobile phone to connect to the hotspot (the default hotspot name is Yahboom_ESP32_WIFI, without a password). Open YahboomCam, enter the camera IP and fill in the default IP address 192.168.4.1 displayed by microbit, and then click Login.

4. The page after login is as follows. You can click the control button on the interface to remotely control the car, such as forward, backward, left turn, right turn, etc. (the servo cannot be controlled by the car), and the real-time image of the camera is also displayed on the app page. The camera can be controlled by the horizontal and vertical control switches of the camera.

6. Extension: STA mode connection

1. Open the URL https://makecode.microbit.org/# in the browser
2. Then drag the microbit-wifi_superkit_STA.hex file provided in this experiment into the browser that opens the URL, and the program diagram of the source code of this project will be automatically opened

3. Set the WiFi name and password to be connected. The WiFi name and password must be filled in correctly according to the WiFi you want to connect to, otherwise there is no way to connect to the WiFi correctly and display the IP address. If the connection is successful, the IP address of sta_ip:192.168.x.x will be displayed. If the connection is unsuccessful, sta_ip:null will be displayed. You need to check whether the WiFi name and address filled in the program are correct.

4. Connect your phone to the WIFI set above, and make sure that the phone and the robot are connected to the same WiFi. Open YahboomCam, enter the camera IP and fill in the sta_ip address displayed by microbit (pay attention to the content displayed by microbit, and it will start to display "sta_ip: 192.168.x.x" after seeing the icon check), and then click to log in. (The IP in the picture is only an example, the specific IP should be based on the microbit display)

5. After logging in, you can see the following page. You can click the control button on the interface to remotely control the car, such as forward, backward, left turn, right turn, etc. (the servo cannot be controlled by this car), and the real-time picture of the camera is also displayed on the app page. The camera can be controlled by the horizontal and vertical control switches of the camera.