elegoo-robot-car4 0.1.0

Python software for controlling the Elegoo Smart Robot Car V4.0

Software suite for the ELEGOO Smart Robot Car Kit V4.0 🤖🚗

This is my personal software suite for the ELEGOO Smart Robot Car Kit V4.0. The original software from ELEGOO is available here.

I started modifying the original software for these main reasons:

1. It requires you to install an app on a smartphone if you want to control the robot, while I wanted to be able to do the same from my computer, e.g. with a game controller. Being able to control the robot from a computer opens a wide range of experimentation possibilities.
2. It does not provide a way to access the MPU6050 sensor (a gyroscope + accelerometer) data out of the box.

WARNING: THIS SOFTWARE IS PROVIDED AS IS, WITH NO WARRANTY

I modified only the software corresponding to the motor driver chip and gyro module I own (see my hardware configuration below). Also the original ELEGOO documentation warns about this point. Verify which is your configuration before blindly uploading my modified software on your robot boards.

Hardware configuration of my robot 🤖🔧⚙️

This is the hardware of my robot:

• motor driver: TB6612
• gyro module: MPU6050
• microcontroller version: Elegoo UNO R3 Car v2.0
• camera: ESP32-WROVER

Repository organization 📂

• src/elegoo_robot_car4: this directory contains a Python package that you can use to control the robot after you have uploaded to the boards the patched ELEGOO software. It also provides a simple Python application that allows you to use the robot as a drone.

• elegoo-patches: this directory contains patchfiles needed for patching the original ELEGOO software to make it work properly together with the provided Python code. I added code for acquiring gyroscope and accelerometer readings and I provide the possibility to make the robot connect to a router instead of creating a WiFi access point. Explore the patchfiles for more details.

• Makefile: this file allows to download the official ELEGOO software for this robot and to patch it. If you already have the official zip file, then copy it into the root of the project, so that the Makefile targets will skip the download.

Prepare the software for the electronic boards 🔧💻

If you are OK with controlling the robot from your smartphone, configure the project with

make config-ap

Otherwise, if you want to control the robot from your computer, configure the project with

make config

You will be requested to enter your router SSID and password.

This procedure works only from Linux or Unix operating systems. If you are on Windows, you have to manually perform what the make config command is doing.

Once configured and patched, upload ELEGOO software to the main board and to the ESP32 in the usual way (described into the official documentation).

WARNING: Remember that you can choose to control the robot either from your computer or from your smartphone but not both (at least with the software I am providing here).

Uploading the ESP32 software 📤

Open the ESP32_CameraServer_AP_<version>.ino sketch of with the Arduino IDE. Then, remove your ESP32 module from the robot and connect it to your computer through a USB-C cable. Then follow these steps (also explained into the robot documentation):

• From Tools -> Port select the right port (for me, on Linux, is something like /dev/ttyUSB0).

• Push the reset button on the ESP32 board. The serial monitor should print some information coming from tha board.

• Open File->Preferences and put https://dl.espressif.com/dl/package_esp32_index.json into the Additional Boards Manager URLs text box. Maybe you already did this in the past. Click "OK".

• Install the right board manager from the Arduino IDE (maybe you already did this in the past). Go to Tools->Boards Manager... and fill esp32 into the search box. Select the package from Espressif Systems and install version 1.0.4. I tried also version 1.0.6 and it works. Version 2.0.0 it does not and you would need to deeply change the code from ELEGOO (not recommended).

• Select the right board: Tools->Board->esp32->ESP32 Dev Module.

• Select the right partition scheme: Tools->Partition Scheme->Huge APP (3MB No OTA/1MB SPIFFS).

• Enable PSRAM: Tools->PSRAM->Enabled.

• Verify the sketch. You may encounter the following issues:

  • ModuleNotFoundError: No module named 'serial': you need to install the pyserial package into your Python environment (pip install pyserial).

  • Arduino IDE complaining that the built result is too large for fitting the board memory. To solve this check the parameters are all correctly set. If they are, it is possible that you had previously installed an esp32 library version more recent than 1.0.6 and then downgraded. It seems that this operation leaves garbage into the downloaded packages. The only solution I've found up to now is to completely remove the .arduinoIDE and .arduino15 directories into my home directory and restart the IDE. Then I had to restart from scratch with the configuration.

• Upload the code to the board.

Now you can check which is the IP address that your router assigned to the board. I aliased it as robot in my /etc/hosts. At this point, we can check the following:

• http://robot provides access to the standard ESP32 web interface.
• http://robot/capture takes a photo.
• http://robot:81/stream provides the streaming from the browser.
• http://robot/Test works (it is an alias for the "stream" endpoint).

You can now reassemble the ESP32 board on the robot.

Uploading the modified main board software 📤

Follow these steps:

• Connect the main board to your computer with the provided USB cable.

• Set the upload-cam switch to upload.

• From the Arduino IDE open the SmartRobotCarV4.0_V1_20230201.ino sketch you find into the ELEGOO software tree, for the configuration with TB6612 and MPU6050 (I did not patch other configurations because I cannot test them).

• Ensure to select the right board: Tools->Board->Arduino UNO (or Tools->Board->Arduino Yun ... they both work). Maybe you need to install support for the arduino boards (in the boards manager, install Arduino AVR Boards).

• Verify the sketch with the Verify button. Maybe you need to install dependencies. These are the dependencies I had to install:

  • Servo, by Michael Margolis, Arduino.

• If everything is OK, upload the code to the board.

I did not need to install packages provided into the addLibrary directory distributed together with ELEGOO software.

Control the robot from your computer 💻🤖

Disconnect the robot from the computer and set back the upload-cam switch to cam. Then, switch on the robot. On the ESP32 you'll notice a blinking green led: the ESP32 is waiting for a client to connect.

Install Python software

You have two options here:

• from within the root of the project, run pip install . (maybe you need to install dependencies).

• install from PyPI: pip install elegoo-robot-car4.

• don't install anything and run through uv from the root of the project (you need to install uv ).

Use Python software

The elegoo_robot_car_4 Python package provides a Car class through which you can provide instructions to the robot and get measurements from its sensors. The class is well documented and you should be able to understand how to use it.

In order to test robot control, stat a Python shell. If robot is the alias assigned to the robot IP (configured into the /etc/hosts file, like described before), you can create an instance with

from elegoo_robot_car4 import Car

car = Car(ip="robot")

As soon as you do that, the green led stops blinking. It means the connection is established. The default port for socket communication is 100 and it is configured into the sketch you uploaded before. Now you can provide commands through the Car instance. For example, to make the robot move forward, type

car.forward()

The robot will move forward indefinietly up to when you issue

car.stop()

Notice that all the methods that have a lazy parameter can also be used in lazy mode. Basically, you provide a command that will be executed only when you use the move method. This lazy mode is mainly useful when controlling the robot with a gamepad (a detailed description of the reason is out of scope here, but has to do with the management of multiple arriving commands by the used game engine). For example, the same effect experimented above can be, achieved in the following way:

car.forward(lazy=True)
car.move()
# Wait for a while
car.stop()

You are encouraged to explore the documentation of each method and to experiment with all of them.

As soon as you close the Python shell you will see the green led blinking again, meaning that it is ready to accept a new connection.

Using the robot like a drone 🤖💻🎮

The elegoo_robot_car4 Python package also provides a program named as elegoo-smartcar-control through which you can control the robot with your keyboard and with a gamepad.

When you have your robot switched on and the ESP32 green led is blinking, you simply have to run

elegoo-smartcar-control robot

if robot is the alias for the actual ESP32 ip address, set into the /etc/hosts file.

If you chose to run with uv, you have to run

uv run elegoo-smartcar-control robot

from the root of the project.

The elegoo-smartcar-control program has been developed like a video game, using a game engine to handle user inputs. Furthermore, OpenCV is used for acquiring and displaying the video stream acquired by the ESP32 camera.

WARNING: Remember that in order to properly issue commands to the robot you have to maintain focus on the window showing the video stream. As soon as you move focus elsewhere, key presses and game pad events are not captured anymore.

Keyboard controls 🤖💻

Keyboard controls are clearly visible at the beginning of the elegoo_smartcar_control.py file, where there is a dictionary mapping each key input to a movement command. There are also mappings to change the mode of the robot. By default the robot waits for a remote connection, but you can switch its mode with the proper keys (this is not possible with the gamepad).

Gamepad controls 🤖🎮

Gamepad offers more degrees of freedom for the movement. I configured controls for the XBOX 360 gamepad. Here below there is a summary of what you can do:

• the left stick and the cross-hats control the movement. While the cross_hat allows only forward, backward and left-rigt rotations on-the-spot, the stick allows you to move the robot forward-left, forward-right, backward-left and backward-right. This is not possible with the keyboard.

• the right trigger controls the speed of the robot. This is not possible with the keyboard at present.

• the right stick controls the rotation of the robot's head.

• the X key resets the head position.

Acknowledgments 🙏✨

Before starting this project I took inspiration from the following videos and sources:

• https://www.youtube.com/watch?v=j7p44vxyvdM
• https://www.youtube.com/watch?v=LyReKO6Pg0g
• https://www.youtube.com/watch?v=y5xmYu25a6c
• https://github.com/bots4a11/ElegooRobotCarV4