How to connect a A02YYUW sensor to an ESP32

Using Arduino Sensors
1

Here is code that I used to connect a A02YYUW ultrasonic sensor with UART to my ESP32-WROOM-32E, Im just posting it because I had to spend a long time getting it working and wasn't able to find a good starting point really, there might be ones already out there but I was able to get this put together from research before I was able to find one. Anyway here it is.

#include <HardwareSerial.h>

#define RXD2 16 // Connect the TX wire form the sensor to GPIO 16
#define TXD2 -1 // Replace the -1 with the GPIO pin you are using if you want to use the RX wire but it is not needed

HardwareSerial SerialPort(2); // Use UART2

unsigned long lastProcessTime = 0; // Last time data was processed
unsigned long lastPrintTime = 0;   // Last time data was printed
const long processInterval = 95;   // Interval for processing data (milliseconds)
const long printInterval = 1000;    // Interval for printing data (milliseconds)

float mostRecentDistance = -1; // Variable to store the most recent distance

void setup() {
  Serial.begin(115200); // Debug serial
  SerialPort.begin(9600, SERIAL_8N1, RXD2, TXD2); // Initialize UART2
  Serial.println("UART Reading Test");
}

void loop() {
  unsigned long currentMillis = millis();

  // Check if it's time to process the next data point
  if (currentMillis - lastProcessTime >= processInterval) {
    lastProcessTime = currentMillis;

    // Process data if available
    if (SerialPort.available()) {
      int header = SerialPort.read();

      if (header == 0xff) {
        // Read the next bytes
        if (SerialPort.available() >= 3) {
          int high = SerialPort.read();
          int low = SerialPort.read();
          int checksum = SerialPort.read();

          // Compute distance
          int distance = ((high << 8) + low);

          // Convert distance to cm
          mostRecentDistance = distance / 10.0;

      // Clear any remaining data in the buffer
      SerialPort.flush();
    } 
  }
  // Check if it's time to print the most recent data
  if (currentMillis - lastPrintTime >= printInterval) {
    lastPrintTime = currentMillis;

    if (mostRecentDistance >= 0) {
      Serial.print("Distance (cm): ");
      Serial.println(mostRecentDistance);
    }
  }
}

if anyone knows of any better code that deals with that data in a more efficient way then posting it here would be appreciated. Also according to a write up I found it says that if you leave the RX wire disconnected i the sensor should default to a reading every 300ms, mine defaults to a reading every 100ms, whatever yours is just make sure that the process interval (in line 10 of the code, i have it set to 95ms) is slightly faster then the sensors reading interval otherwise readings will get queued up over time and it will take the serial monitor a while to actually print a change in distance. Hopefully this is helpful to someone because it should would have been helpful to me when I got the sensor a couple days ago.

2

I've moved your topic as you're not using an Arduino Nano ESP32. The Arduino Nano ESP32 section is only for problems with, you guess, the Arduino Nano ESP32 :wink: