A02YYUW Sensor Setup Guide for Arduino & ESP32

This project integrates the A02YYUW Ultrasonic Sensor into HomeAssistant to monitor detection distances in real time.

Hardware Preparation

A02YYUW Waterproof Ultrasonic Distance Sensor (Purchase Link)
FireBeetle 2 ESP32-C6 IoT Development Board (Purchase Link) (Other FireBeetle boards are also compatible)
HomeAssistant host device

Software Preparation

Ensure the ESPHome plugin is installed in HomeAssistantOS

Wiring Diagram

Adding a New Device in ESPHome 1. Click the **NEW DEVICE** button on the ESPHome homepage

2. Click **CONTINUE**

3. Enter your device name and click **NEXT**

4. Select your development board model

5. Save the device's Encryption key and click **SKIP**

6. Click **EDIT** on the device card in ESPHome to view the auto-generated default program

Modifying the Code

Append the following code to the end of the auto-generated program, maintaining proper indentation and line breaks:

uart:
  tx_pin: GPIO16
  rx_pin: GPIO17
  baud_rate: 9600
  id: uart_a

sensor:
  - platform: "a02yyuw"
    name: "A02YYUW Distance"
    uart_id: uart_a

Code explanation reference: Link

First Firmware Installation

After modifying the code, click INSTALL
For the first installation, select Plug into this computer. Subsequent updates can use Wirelessly (OTA).
After compilation completes, click Download project
Select Factory format (Previously Modern) to download the firmware locally
Connect the development board to your computer and click Open ESPHome Web
Select your device's serial port:
Select the firmware and flash:
Wait for the flashing process to complete