Working with Arduino

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

Arduino Getting Started
Setting Up the 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 the Development Environment

1. Installing and Configuring the Arduino IDE

info

For the ESP32-S3-RLCD-4.2 development board, the Arduino IDE requires the installation of arduino-esp32 v3.3.0 or higher.

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

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 example program package for the ESP32-S3-RLCD-4.2 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	v8.3.11/v9.3.0	"Install Offline"
SensorLib	Sensor library	v0.3.1	"Install Online" or "Install Offline"

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

Example

The Arduino examples are located in the Arduino/examples directory of the example package.

Example	Basic Program Description	Dependency Library
01_WIFI_AP	Set to AP mode to obtain the IP address of the access device	-
02_WIFI_STA	Set to STA mode to connect to Wi-Fi and obtain an IP address	-
03_ADC_Test	Get the voltage value of the lithium battery	-
04_I2C_PCF85063	Print real-time time of RTC chip	SensorLib
05_I2C_SHTC3	Print temperature and humidity sensor data	-
06_SD_Card	Load and display TF card information	-
07_Audio_Test	Play the sound recorded by the microphone through the speaker	LVGL V8.3.11
08_LVGL_V8_Test	LVGLV8 example	LVGL V8.3.11
09_LVGL_V9_Test	LVGLV9 example	LVGL V9.3.0
10_U8G2_Test	U8G2 porting example	U8G2 master

01_WIFI_AP

Example Description

This example can set the development board as a hotspot, allowing phones or other devices in STA mode to connect to the development board.

Hardware Connection

Connect the board to the computer using a USB cable.

Code Analysis

*In the file 01_WIFI_AP.ino, find ssid and password, then a phone or other device in STA mode can connect to the development board using these ssid and password.

const char *ssid = "ESP32_AP";
const char *password = "12345678";

Operation Result

After flashing the program, open the Serial Terminal. If a device successfully connects to the hotspot, the MAC address of that device will be output, as shown:

02_WIFI_STA

Example Description

This example configures the development board as a STA device to connect to a router, thereby accessing the system network.

Hardware Connection

Connect the board to the computer using a USB cable.

Code Analysis

In the file 02_WIFI_STA.ino, find ssid and password, then modify them to the SSID and Password of an available router in your current environment.
```
const char *ssid = "you_ssid";
const char *password = "you_password";
```

Operation Result

After flashing the program, open the Serial Terminal. If the device successfully connects to the hotspot, the obtained IP address will be output, as shown in the figure:

03_ADC_Test

Example Description

The analog voltage connected through the GPIO is converted to digital by the ADC, and then the actual lithium battery voltage is calculated and printed to the terminal.

Hardware Connection

Connect the board to the computer using a USB cable.

Code Analysis

Adc_PortInit(void): Initializes ADC1, including creating an ADC one-time trigger unit and configuring channel 3 for ADC1
float Adc_GetBatteryVoltage(int *data): Reads the value from ADC1 channel 3 and returns the actual voltage value.
uint8_t Adc_GetBatteryLevel(void): Returns the battery percentage.
void Adc_LoopTask(void *arg): Creates an ADC task that reads the ADC value and prints it to the serial port every second.

Operation Result

After the program is compiled and downloaded, you can view the printed ADC values and voltage output by opening the Serial Monitor, as shown in the following image:

04_I2C_PCF85063

Example Description

Through the I2C protocol, initialize the PCF85063 chip, set the time, and then periodically read the time and print it to the terminal

Hardware Connection

Connect the board to the computer using a USB cable.

Code Analysis

I2cMasterBus I2cbus(14,13,0);          // Initialize I2C bus
void setup() {
Serial.begin(115200);
delay(1000);
Serial.printf("rtc-example run \n"); 
Rtc_Setup(&I2cbus, 0x51);              // Initialize RTC, set RTC slave address to 0x51
Rtc_SetTime(2025, 9, 9, 20, 15, 30);   // Set RTC time
}

void loop() {
  rtcTimeStruct_t rtcData;
  Rtc_GetTime(&rtcData);              // Get the real-time clock (RTC) time
  Serial.printf("%d/%d/%d %02d:%02d:%02d \n",
                rtcData.year, rtcData.month, rtcData.day, rtcData.hour, rtcData.minute,
                rtcData.second);
  delay(1000);
}

Operation Result

After the program is compiled and downloaded, open the serial port monitoring to see the RTC time of the printout, as shown in the following figure:

05_I2C_SHTC3

Example Description

Initialize the SHTC3 chip through the I2C protocol, and then print the temperature and humidity information read every 1 second to the terminal

Hardware Connection

Connect the board to the computer using a USB cable.

Code Analysis

I2cMasterBus I2cbus(14,13,0);
Shtc3Port *shtc3port = NULL;

void setup() {
  Serial.begin(115200);
  delay(1000);
  Serial.printf("shtc3-example run \n");
  shtc3port = new Shtc3Port(I2cbus);         // Initialize SHTC3
}

void loop() {
  float rh,temp;
  shtc3port->Shtc3_ReadTempHumi(&temp,&rh);  // Get temperature and humidity data
  Serial.printf("RH:%.2f%%,Temp:%.2f° \n",rh,temp);
  delay(1000);
}

Operation Result

Open the serial port monitor, you can see the printed temperature and humidity data, as shown in the figure below:

06_SD_Card

Example Description

Drive the TF card through SDMMC, and print the TF card information to the terminal after successfully mounting.

Hardware Connection

Install a FatFs-formatted TF card into the board before powering on

Code Analysis

#define sdcard_write_Test                  

CustomSDPort *sdcardPort = NULL;

void setup()
{
  Serial.begin(115200);
  delay(2000);
  sdcardPort = new CustomSDPort("/sdcard");  // Initialize SDMMC driver
}

uint32_t value = 1;
char sdcard_read[45] = {""};
char sdcard_write[45] = {""};

void loop()
{
#ifdef sdcard_write_Test      // Test the TF card read/write functionality
  snprintf(sdcard_write,45,"sdcard_writeTest : %ld \n",value);
  sdcardPort->SDPort_WriteFile("/sdcard/writeTest.txt",sdcard_write,strlen(sdcard_write));
  vTaskDelay(pdMS_TO_TICKS(500));
  sdcardPort->SDPort_ReadFile("/sdcard/writeTest.txt",(uint8_t *)sdcard_read,NULL);
  Serial.printf("read data:%s\n",sdcard_read);
  vTaskDelay(pdMS_TO_TICKS(500));
  value++;
#endif
}

Operation Result

Click on the serial port monitoring device, you can see the output information of the TF card, as shown in the figure below:

07_Audio_Test

Example Description

Demonstrates how to get data from the microphone and then play it through the speaker

Hardware Connection

Connect the board to the computer using a USB cable.

Code Analysis

CodecPort_SetInfo("es8311 & es7210",1,16000,2,16): Sets the sampling rate, number of channels, and bit depth of the Codec chip.
CodecPort_SetSpeakerVol(100): Set the playback gain to 100.
CodecPort_SetMicGain(35): Set the microphone gain to 35.
Codec_LoopTask(void *arg): Codec task, which implements recording, playback, and other functions.

Operation Result

After the program is flashed, as shown in the figure:
tip
1. Double-click the BOOT button to enter recording mode, speak into the MIC, and it will automatically end after 3 seconds
2. Click the BOOT button to play the sound you just recorded
3. Double-click the KEY button to play a piece of music
4. Click the KEY button to interrupt music playback

08_LVGL_V8_Test

Example Description

Demonstrates how to display images using LVGL V8, helping users get started quickly with LVGL V8.

Hardware Connection

Connect the board to the computer using a USB cable.

Code Analysis

/*Create an IMG1 widget */
ui->screen_img_1 = lv_img_create(ui->screen);
lv_obj_add_flag(ui->screen_img_1, LV_OBJ_FLAG_CLICKABLE);
lv_img_set_src(ui->screen_img_1, &_ein_alpha_400x300);
lv_img_set_pivot(ui->screen_img_1, 50,50);
lv_img_set_angle(ui->screen_img_1, 0);
lv_obj_set_pos(ui->screen_img_1, 0, 0);
lv_obj_set_size(ui->screen_img_1, 400, 300);
/*Create an IMG2 widget */
ui->screen_img_2 = lv_img_create(ui->screen);
lv_obj_add_flag(ui->screen_img_2, LV_OBJ_FLAG_CLICKABLE);
lv_img_set_src(ui->screen_img_2, &_2_alpha_400x300);
lv_img_set_pivot(ui->screen_img_2, 50,50);
lv_img_set_angle(ui->screen_img_2, 0);
lv_obj_set_pos(ui->screen_img_2, 0, 0);
lv_obj_set_size(ui->screen_img_2, 400, 300);
lv_obj_add_flag(ui->screen_img_2, LV_OBJ_FLAG_HIDDEN);

Operation Result

After the program is flashed, it is displayed alternately at intervals of 1.5 seconds, as shown in the figure:

09_LVGL_V9_Test

Example Description

Demonstrates how to display images using LVGL V9, helping users get started quickly with LVGL V9.

Hardware Connection

Connect the board to the computer using a USB cable.

Code Analysis

/*Create an IMG1 widget */
ui->screen_img_1 = lv_image_create(ui->screen);
lv_obj_set_pos(ui->screen_img_1, 0, 0);
lv_obj_set_size(ui->screen_img_1, 400, 300);
lv_obj_add_flag(ui->screen_img_1, LV_OBJ_FLAG_CLICKABLE);
lv_image_set_src(ui->screen_img_1, &_ein_RGB565A8_400x300);
lv_image_set_pivot(ui->screen_img_1, 50,50);
lv_image_set_rotation(ui->screen_img_1, 0);
/*Create an IMG2 widget */
ui->screen_img_2 = lv_image_create(ui->screen);
lv_obj_set_pos(ui->screen_img_2, 0, 0);
lv_obj_set_size(ui->screen_img_2, 400, 300);
lv_obj_add_flag(ui->screen_img_2, LV_OBJ_FLAG_HIDDEN);
lv_obj_add_flag(ui->screen_img_2, LV_OBJ_FLAG_CLICKABLE);
lv_image_set_src(ui->screen_img_2, &_2_RGB565A8_400x300);
lv_image_set_pivot(ui->screen_img_2, 50,50);
lv_image_set_rotation(ui->screen_img_2, 0);

Operation Result

After the program is flashed, it is displayed alternately at intervals of 1.5 seconds, as shown in the figure:

10_U8G2_Test

Example Description

Completes the porting of the U8G2 library, supporting fast screen refreshing, helping users precisely target product functions and display effects.

Hardware Connection

Connect the board to the computer using a USB cable.

Code Analysis

u8g2_clearBuffer();     // Clear screen
u8g2_setFont();         // Set font
u8g2_drawStr();         // Draw counter and text
u8g2_drawFrame();       // Draw border
u8g2_drawHLine();       // Draw bottom separator line
u8g2_sendBuffer();      // Refresh screen
u8g2_drawPixel(x, y);   // Draw a pixel
u8g2_drawLine(x1, y1, x2, y2);    // Draw an arbitrary line
u8g2_drawBox(x, y, w, h);         // Filled rectangle
u8g2_drawCircle(x, y, r);         // Hollow circle
u8g2_drawDisc(x, y, r);           // Filled circle
u8g2_drawTriangle(x0, y0, x1, y1, x2, y2); // Filled triangle
u8g2_drawXBMP(x, y, w, h, bitmap); // Draw XBM format monochrome bitmap
u8g2_drawBitmap(x, y, cnt, h, bitmap); // Draw U8g2 bitmap

Operation Result

After the program is flashed, the screen displays as shown:
tip
1. FPS can reach 74 frames, suitable for fast‑refresh applications.

Give Feedback

Arduino Getting Started​

Setting Up the Development Environment​

1. Installing and Configuring the Arduino IDE​

2. Installing Libraries​

3. Arduino Project Parameter Settings​

Example​

01_WIFI_AP​

02_WIFI_STA​

03_ADC_Test​

04_I2C_PCF85063​

05_I2C_SHTC3​

06_SD_Card​

07_Audio_Test​

08_LVGL_V8_Test​

09_LVGL_V9_Test​

10_U8G2_Test​

Arduino Getting Started

Setting Up the Development Environment

1. Installing and Configuring the Arduino IDE

2. Installing Libraries

3. Arduino Project Parameter Settings

Example

01_WIFI_AP

02_WIFI_STA

03_ADC_Test

04_I2C_PCF85063

05_I2C_SHTC3

06_SD_Card

07_Audio_Test

08_LVGL_V8_Test

09_LVGL_V9_Test

10_U8G2_Test