Working with Arduino

This chapter contains the following sections. Please read as needed:

Arduino Getting Started
Setting Up Development Environment
Example

Arduino Getting Started

New to Arduino ESP32 development and looking for a quick start? We have prepared a comprehensive Getting Started Tutorial for you.

Note: This tutorial uses the ESP32-S3-Zero as a reference example, and all hardware code is based on its pinout. Before you start, we recommend checking the pinout of your development board to ensure the pin configuration is correct.

Setting Up Development Environment

1. Installing and Configuring Arduino IDE

Please refer to the tutorial Installing and Configuring Arduino IDE to download and install the Arduino IDE and add ESP32 support.

Board Name	Board Installation Requirement	Version Requirement
esp32 by Espressif Systems	"Offline Installation" / "Online Installation"	3.2.0

2. Installing Libraries

When installing Arduino libraries, there are typically two methods: Install Online and Install Offline. If the library installation requires Install Offline, you must use the provided library file.
For most libraries, users can easily search for and install them via the Arduino IDE's online Library Manager. However, some open-source or custom libraries are not synchronized to the Arduino Library Manager and therefore cannot be found through online search. In this case, users can only install these libraries manually via offline methods.
The sample program package for the ESP32-S3-DualEye-LCD-1.28 development board can be downloaded from here. The Arduino\libraries directory within the package already contains all the library files required for this tutorial.

Library/File Name	Description	Version	Installation Method
LVGL	Graphics Library	v8.3.10	"Offline Installation"
ESP32-audioI2S-master	Audio Decoding Library	v2.0.0	"Offline Installation"
es7210	Audio Decoding Library	xxx	"Offline Installation"
es8311	Audio Decoding Library	xxx	"Offline Installation"

Version Compatibility Notes

There are strong dependencies between versions of LVGL and its driver libraries. For example, a driver written for LVGL v8 may not be compatible with LVGL v9. To ensure that the examples can be reproduced reliably, it is recommended to use the specific versions listed in the table above. Mixing different versions of libraries may lead to compilation failures or runtime errors.

3. Arduino Project Parameter Settings

If the example being flashed contains a speech recognition model, select "ESP SR 16M (3MB APP/7MB SPIFFS/2.9MB MODEL)" for the Partition Scheme.
If the example being flashed does not contain a speech recognition model, select "16M Flash (3MB APP/9.9MB FATFS)" or another appropriate scheme.

Example

LVGL_Arduino

Example Description

This example demonstrates the functionality of the onboard devices. Screen 2 displays parameters such as TF Card and Flash Size, while Screen 1 is the music playback interface. Additionally, this example adds speech recognition functionality.

Hardware Connection

Insert the TF card into the development board
Connect the development board to the computer.

Code Analysis

setup(): Hardware initialization, peripheral configuration, etc.
- Hardware initialization: Inside setup(), multiple initialization functions are executed to configure and initialize hardware components connected to the Arduino, such as the LCD display, TF card, audio module, and microphone. These initializations ensure that the hardware operates correctly.
- GUI Initialization: Calls Lvgl_Init() to initialize LVGL (Light and Versatile Graphics Library), a widely used graphics library for embedded systems. Lvgl_Example1() is an example program used to demonstrate how to render a graphical interface on the display.
loop(): Adds a delay to prevent triggering the watchdog timer.

Operation Result

LCD Screen Display

LCD Screen Display Parameter Description

Parameter	Function	Description
SD Card	Displays the TF card size	Connect a TF card. If recognition fails, please format the TF card to FAT32 (if initial recognition fails, wait a moment and then reset to check again)
Flash Size	Displays the Flash size	Onboard 16MB Flash
Battery Voltage	Battery voltage	Battery voltage can be detected when a battery is connected

Screen 1 is the UI page for playing MP3 audio files stored in the root directory of the TF card.
The BOOT button controls the UI: short press to switch the selected item, double‑press to confirm, long press to switch screen focus.
This program enables voice recognition by default. The wake word is "hi esp". After waking up, the backlight dims, and you can speak the command (if the backlight does not dim, it means it was not woken up; recognition requires standard pronunciation and a slower speaking pace)
Several MIC test audio formats are provided below (Note: if the "hi esp" wake-up fails, please reposition the audio to the point where the wake word is played and try again)
Please do not perform voice recognition while audio is being played through the speaker
The reason the test audio plays the wake word twice is that the current firmware version requires a focus step for the first wake-up (metaphorically), and the current firmware does not allow disabling this feature
```
  // Commands
  Turn on the backlight
  Turn off the backlight
  Backlight is brightest
  Backlight is darkest
```
Note: In this example, speech recognition is only available before playing audio.

Switching Between Chinese/English Recognition Models

The initial state of the environment defaults to the English recognition environment. Follow the steps below to switch to the Chinese recognition model or revert to the English recognition model.

Switching to Chinese Recognition Model

Setting Up the Chinese Recognition Environment

Download the provided program file Program using the Chinese model
Navigate to the path C:\Users\Waveshare\AppData\Local\Arduino15\packages\esp32\hardware\esp32\3.0.2\libraries\ESP_SR\src (where Waveshare is the computer username)
Replace the esp32-hal-sr.c file in this path with the downloaded file
Download the Chinese model Chinese Model - Wake Word 'hi lexin'
Navigate to the path C:\Users\Waveshare\AppData\Local\Arduino15\packages\esp32\tools\esp32-arduino-libs\idf-release_v5.1-bd2b9390ef\esp32s3\esp_sr (where Waveshare is the computer username)
Replace the srmodels.bin file in this path with the downloaded file
Modify the recognition commands in the program to Chinese commands (using Pinyin)

Switching to English Recognition Model

The initial state of the environment defaults to the English recognition environment. If it has not been switched to Chinese, do not perform the following modifications
If it was previously modified for Chinese recognition, download the provided program file Program Using English Model(https://files.waveshare.com/wiki/common/Use_the_English_model_program.zip)
Navigate to the path C:\Users\Waveshare\AppData\Local\Arduino15\packages\esp32\hardware\esp32\3.0.2\libraries\ESP_SR\src (where Waveshare is the computer username)
Replace the esp32-hal-sr.c file in this path with the downloaded file
Download the English model English Model - Wake Word 'hi esp'
Navigate to the path C:\Users\Waveshare\AppData\Local\Arduino15\packages\esp32\tools\esp32-arduino-libs\idf-release_v5.1-bd2b9390ef\esp32s3\esp_sr (where Waveshare is the computer username)
Replace the srmodels.bin file in this path with the downloaded file
Modify the recognition commands in the program to English commands (using phonemes)

Give Feedback

Arduino Getting Started​

Setting Up Development Environment​

1. Installing and Configuring Arduino IDE​

2. Installing Libraries​

3. Arduino Project Parameter Settings​

Example​

LVGL_Arduino​

Example Description​

Hardware Connection​

Operation Result​

Switching Between Chinese/English Recognition Models​