SunFounder Pico-4wd car User manual

SunFounder pico_4wd_car
www.sunfounder.com
Sep 21, 2022

CONTENTS
1 Get Started 5
1.1 1. Install Thonny IDE .......................................... 5
1.2 2. Install MicroPython on Your Pico ................................... 7
1.3 3. Upload the Libraries to Pico ...................................... 11
1.4 4. Test the Modules ........................................... 14
1.5 5. Assemble the Car ........................................... 25
1.6 6. Examples ............................................... 25
2 Appendix 53
2.1 Introduction to Raspberry Pi Pico .................................... 53
2.2 Introduction to Pico RDP ........................................ 55
2.3 Schematic and Structure Drawing .................................... 56
2.4 Thonny IDE Introduction ........................................ 57
3 FAQ 59
3.1 Q1: NO MicroPython(Raspberry Pi Pico) Interpreter Option on Thonny IDE? ............. 59
3.2 Q2: Cannot open Pico code or save code to Pico via Thonny IDE? ................... 60
4 Thank You 61
5 Copyright Notice 63
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SunFounder pico_4wd_car
The Pico-4wd is a Raspberry Pi Pico based, cool, robot car kit that everyone can have.
Equipped with greyscale sensor module and ultrasonic module, it can perform line tracking, cliff detection, follow and
obstacle avoidance functions. The RGB boards assembled at the bottom and rear of the car make it the coolest spirit
in the dark.
We have provided sample code based on MicroPython so you can get started quickly.
In addition, you can also use an app - SunFounder Controller - to DIY your own control methods! Let’s Play!
Here is the Email: [e-mail].
About the display language
In addition to English, we are working on other languages for this course. Please contact [e-mail] if
you are interested in helping, and we will give you a free product in return. In the meantime, we recommend using
Google Translate to convert English to the language you want to see.
The steps are as follows.
• In this course page, right-click and select Translate to xx. If the current language is not what you want, you can
change it later.
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SunFounder pico_4wd_car
• There will be a language popup in the upper right corner. Click on the menu button to choose another language.
• Select the language from the inverted triangle box, and then click Done.
Source Code
2 CONTENTS

SunFounder pico_4wd_car
SunFounder Pico-4wd Car Code
Or check out the code at
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SunFounder pico_4wd_car
4 CONTENTS

CHAPTER
ONE
GET STARTED
In this section, you will learn all the hardware and software configurations needed to get Pico-4wd up and running,
and it is recommended that you read them in order.
1.1 1. Install Thonny IDE
Before you can start to program Pico with MicroPython, you need an integrated development environment (IDE), here
we recommend Thonny. Thonny comes with Python 3.7 built in, just one simple installer is needed and you’re ready
to learn programming.
Note: Since the Raspberry Pi Pico interpreter only works with Thonny version 3.3.3 or later, you can skip this chapter
if you have it; otherwise, please update or install it.
1. You can download it by visiting the website. Once open the page, you will see a light gray box in the upper right
corner, click on the link that applies to your operating system.
2. The installers have been signed with a new certificate which hasn’t built up its reputation yet. You may need
to click through your browser warning (e.g. choose “Keep” instead of “Discard” in Chrome) and Windows
Defender warning (More info Run anyway).
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3. Next, click Next and Install to finish installing Thonny.
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1.2 2. Install MicroPython on Your Pico
MicroPython is a software implementation of a programming language largely compatible with Python 3, written in
C, that is optimized to run on a microcontroller.
MicroPython consists of a Python compiler to bytecode and a runtime interpreter of that bytecode. The user is pre-
sented with an interactive prompt (the REPL) to execute supported commands immediately. Included are a selection
of core Python libraries; MicroPython includes modules which give the programmer access to low-level hardware.
• Reference:
Now come to install MicroPython into Raspberry Pi Pico, Thonny IDE provides a very convenient way for you to
install it with one click.
Note: If you do not wish to upgrade Thonny, you can use the Raspberry Pi official by dragging and dropping an
rp2_pico_xxxx.uf2 file into Raspberry Pi Pico.
1. Open Thonny IDE.
1.2. 2. Install MicroPython on Your Pico 7

SunFounder pico_4wd_car
2. Press and hold the BOOTSEL button and then connect the Pico to computer via a Micro USB cable. Release
the BOOTSEL button after your Pico is mount as a Mass Storage Device called RPI-RP2.
3. In the bottom right corner, click the interpreter selection button and select Install Micropython.
Note: If your Thonny does not have this option, please update to the latest version.
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4. In the Target volume, the volume of the Pico you just plugged in will automatically appear, and in the Mi-
cropython variant, select Raspberry Pi.Pico/Pico H.
1.2. 2. Install MicroPython on Your Pico 9

SunFounder pico_4wd_car
5. Click the Install button, wait for the installation to complete and then close this page.
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Congratulations, now your Raspberry Pi Pico is ready to go.
1.3 3. Upload the Libraries to Pico
Before using Pico-4wd Car, you need to upload its related libraries in Raspberry Pi Pico.
1. Download the relevant code from the link below.
•SunFounder Pico-4wd Car Code
2. Open Thonny IDE and plug the Pico into your computer with a micro USB cable and click on the “MicroPython
(Raspberry Pi Pico).COMXX” interpreter in the bottom right corner.
1.3. 3. Upload the Libraries to Pico 11

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3. In the top navigation bar, click View -> Files.
4. Switch the path to the folder where you downloaded the code package before, and then go to the
pico_4wd_car_main/libs folder.
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5. Select these 3 files, right-click and click Upload to, it will take a while to upload.
6. Now you will see the files you just uploaded inside your drive Raspberry Pi Pico.
1.3. 3. Upload the Libraries to Pico 13

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1.4 4. Test the Modules
This chapter is suitable for usability testing of the modules before assembly; or for final commissioning and mainte-
nance of the Pico-4wd after assembly has been completed.
1.4.1 Power up the Pico RDP
In order to make the module work, you need to power up the Pico RDP and turn the power switch to ON.
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1.4.2 Test the Motors
1. Connect the 4 motors according to the diagram below.
2. Select Correct Interpreter
Plug the Pico into your computer with a micro USB cable and select the “MicroPython (Raspberry
Pi Pico).COMXX” interpreter in the bottom right corner.
3. Go to the pico_4wd_car_main/tests path and double click on test_motor.py to open it.
1.4. 4. Test the Modules 15

SunFounder pico_4wd_car
4. Click the Run current script button or just press F5 to run it.
Now, you can see the four motors work in a regular pattern. If you complete the assembly, this code will make the
Pico-4wd perform five movements: forward, backward, left, right and stop.
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