Hardware connection

• Connect the board to the computer using a USB cable

Code analysis

• loop():

loop()The function is the main loop part of the program, and its core function is to scan devices on the I2C bus.
First, variables were defined to store error codes, device addresses, and to record the number of devices found.
Then, iterate through possible I2C device addresses from location 0x01 to 0x7f using a loop. For each address, use Wire.beginTransmission(address) to start the transmission to the device at the specific address, and then use Wire.endTransmission() to end the transmission and get the error code.
If the error code is 0, an I2C device was found at that address, print the device address and increase the count of the number of devices. If the error code is not 2 (indicating that the device is not responding), the error code and the corresponding address are printed.
Finally, if no I2C devices are found, print the appropriate message and use delay(5000) to pause the program for 5 seconds and scan again.

Demo flashing

• Select the development board ESP32S3 Dev Module and port
• Set development board parameters
  

• Flash the demo

Result demonstration

• The serial monitor prints the device address on the I2C bus
  

Hardware connection

• Connect the board to the computer using a USB cable
• Connect the development board to USB to RS485 converter, as shown in the figure

Code analysis

• setup():

setup function is primarily used for initializing serial communication
Use the RS485.begin function to initialize serial port Serial1, set the baud rate, data format, and specify the receive and transmit pins. Then, through a loop, ensure the serial port initialization is successful.

• loop() :

loop function is the main loop part of the program, and its main function is to implement simple 485 communication data return
By checking whether there is data available at the serial port, if there is data, it reads a byte and sends it back immediately, so that the received 485 data can be sent back intact

Demo flashing

• Select the development board ESP32S3 Dev Module and port
• Set development board parameters
  

• Flash the demo

Result demonstration

• Open the serial port debugging assistant to send a message to the ESP32-S3-Touch-LCD-7 device, and the device will return the received message to the serial port debugging assistant

Hardware connection

• Connect the board to the computer using a USB cable
• Connect the PH2.0 to 2.54mm male connector to the Sensor AD interface of the board

Code analysis

• setup():

The setup function first initializes the serial communication, then initializes the ADC, and sets the ADC resolution to 12 bits (0-4096).

• loop() :

The loop function reads the current AD value every 100ms and prints the current AD value.

Demo flashing

• Select the development board ESP32S3 Dev Module and port
• Set development board parameters
  

• Flash the demo

Result demonstration

• Result demonstration: ESP32-S3-Touch-LCD-7 will set the ADC resolution, read the current AD value, and print to the serial port terminal

Hardware connection

• Connect the UART port of the board to the computer using a USB cable

Code analysis

• setup():

setup function is primarily used for initializing serial communication
Use the UART.begin function to initialize serial port Serial , set the baud rate, data format, and specify the receive and transmit pins. Then, through a loop, ensure the serial port initialization is successful.

• loop() :

loop function is the main loop part of the program, and its main function is to implement simple UART communication data return
By checking whether there is data available at the serial port, if there is data, it reads a byte and sends it back immediately, so that the received UART data can be sent back intact

Demo flashing

• Select the development board ESP32S3 Dev Module and port
• Set development board parameters
  

• Flash the demo

Result demonstration

• Open the serial port debugging assistant to send a message to the ESP32-S3-Touch-LCD-7 device, and the device will return the received message to the serial port debugging assistant

Hardware connection

• Connect the board to the computer using a USB cable
• Connect the development board to USB-CAN-A, as shown in the figure

Code analysis

• waveshare_twai_transmit():
• waveshare_twai_transmit() function primarily handles the transmission and alarm processing for TWAI (an interface similar to CAN bus)
  
  • First, it checks if any alarms have occurred. Read the triggered alerts by calling twai_read_alerts and obtain the TWAI status information into a twai_status_info_t structure. Then, according to the different alarms triggered, perform corresponding processing. For example, if an error passive alarm, a bus error alarm, a transmission failure alarm, or a transmission success alarm is triggered, print the corresponding message and output some status information such as the bus error count, the number of messages to be sent, the transmission error counter, and the transmission failure counter.
  • It then takes the current time (in milliseconds) and checks if it's time to send the message. If the difference between the current time and the last time a message was sent is greater than or equal to the set transmission time interval TRANSMIT_RATE_MS , then update the last send time to the current time and call the send_message function to send a message. send_message function configures and queues a message containing a specific identifier, data length, and data content for transmission. If the queuing is successful, it prints a success message; otherwise, it prints a failure message. After sending, it clears the message data array.

Demo flashing

• Select the development board ESP32S3 Dev Module and port
• Set development board parameters
  

• Flash the demo

Result demonstration

• Serial port print indicates successful CAN message transmission. After configuring USB-CAN-A_TOOL, you can observe the CAN messages sent by the ESP32-S3-Touch-LCD-7 upon startup

Hardware connection

• Connect the board to the computer using a USB cable
• Connect the development board to USB-CAN-A, as shown in the figure

Code analysis

• waveshare_twai_receive():
  • First, the triggered alarm is read and the status information is obtained, and the corresponding processing is carried out according to different alarm conditions, such as printing error passive, bus error, receiving queue full and other alarm information and related counts.
  • When a data alert is triggered, the loop receives messages and calls the handle_rx_message function to process them. This function determines the message format and prints the message identifier and data content (excluding remote transmission requests), effectively handling received messages on the TWAI bus and responding to alerts.

Demo flashing

• Select the development board ESP32S3 Dev Module and port
• Set development board parameters
  

• Flash the demo

Result demonstration

• ESP32-S3-Touch-LCD-7 waits USB-CAN-A_TOOL to send a message. If the message is received successfully, it will be printed to the serial port

Hardware connection

• Connect the board to the computer using a USB cable

Code analysis

• waveshare_lcd_init():
  • First, it prints out "Initialize IO expander" to indicate the start of initializing the IO expander. Then create a ESP_IOExpander_CH422G instance, initialize it, and start its operation. Set IO0 - IO7 pins to output mode, and set the touch screen reset pin (TP_RST) and the LCD reset pin (LCD_RST) to high level while turning off the LCD backlight (LCD_BL) and wait 100 ms.
  • Next, print "Create RGB LCD bus", create an RGB panel bus object ESP_PanelBus_RGB, configure its pins, width, height, RGB timing frequency and timing parameters, etc., set the bounce buffer size and display the active low flag, and then start the panel bus operation.
  • Then, print "Create LCD device", create an LCD object ESP_PanelLcd, pass in parameters such as panel bus object, number of color bits, and reset pins to initialize, reset, and start the operation. If EXAMPLE_ENABLE_PRINT_LCD_FPS is defined, the callback function ending with VSync is attached to the LCD object.
  • Finally, print "Draw color bar from top left to bottom right, the order is B - G - R", call the colorBarTest function to draw the color bar on the LCD, and turn on the LCD backlight.

Demo flashing

• Select the development board ESP32S3 Dev Module and port
• Set development board parameters
  

• Flash the demo

Result demonstration

• Serial port prints log, and the screen lights up

Hardware connection

• Connect the board to the computer using a USB cable

Code analysis

• setup():

Initialize serial communication at a baud rate of 115200. Next, create and initialize the IO expander, set the pin mode and state, and initialize the GT911 touch screen. Then create and initialize the panel device, configure the RGB bus as needed. After that, initialize LVGL, create a simple label or an example or demo function that optionally calls LVGL, and release the mutex lock at the end

• loop() :

Only prints "IDLE loop" and waits for 1 second without any other substantial action. The overall goal is to build an LVGL-based user interface environment.

Code modification

• In ESP_Panel_Board_Custom.h there is a macro definition for selecting whether to turn on the touch function, with a value of 0 corresponds to turning off touch, and a value of 1 corresponds to turning on touch, which can be selected according to the model purchased
  

 #define ESP_OPEN_TOUCH 0 // 1 initiates the touch, 0 closes the touch.

Demo flashing

• Select the development board ESP32S3 Dev Module and port
• Set development board parameters
  

• Flash the demo

Result demonstration

• Serial port prints the screen refresh rate, and the screen lights up

Screen lights up_video

Other instructions

• Screen drifting occurs during use, please refer to ESP official FAQ
• When using your own UI program, there is a lack of memory, you can click Tools to select a larger partition table
  
  
• The version of lvgl used is 8.4, and you can query and use the LVGL API through the following documentation
  • LVGL documentation