Integrating an RS485 Sensor with ESP32

In this guide, we will explore how to connect an RS485 sensor, the XY-MD02, to an ESP32 microcontroller using an MAX485 module. We’ll go through the necessary components, wiring setup, and the code required to get temperature readings from the sensor.

What You Need

• XY-MD02 Sensor (Amazon): This is an RS485 Modbus RTU protocol sensor, commonly used for measuring temperature and humidity.
• ESP32 Microcontroller (Amazon)
• MAX485 Module (Amazon): This module is used to convert TTL signal levels to RS485.
• 12V Power Supply 10A (Amazon): To power the XY-MD02 Sensor.

Wiring

Please follow the following wiring diagram,

Code

Here is the complete code I used.

#include <ModbusMaster.h>

#define MAX485_DE      32
#define MAX485_RE_NEG  33

#define RXD2 16
#define TXD2 17

ModbusMaster node;

void preTransmission()
{
  digitalWrite(MAX485_RE_NEG, 1);
  digitalWrite(MAX485_DE, 1);
}

void postTransmission()
{
  digitalWrite(MAX485_RE_NEG, 0);
  digitalWrite(MAX485_DE, 0);
}

void…