JW01 eCo2 Uart Module

The YYS JW01 (often labeled JW01-V2.2 or JW01-CO2) is a semiconductor air quality sensor module for detecting carbon dioxide ( ), commonly integrated into home appliances. It features UART output (5V level), 350-2000ppm detection range, high sensitivity, and automatic calibration with temperature/humidity compensation

#include <SoftwareSerial.h>

#define JW_RX D5
#define JW_TX D6
#define NUM_SAMPLES 5   // number of readings to average

SoftwareSerial jwSerial(JW_RX, JW_TX);

byte frame[6];
int readings[NUM_SAMPLES];
int idx = 0;      // renamed from 'index'
bool filled = false;

void setup() {
  Serial.begin(115200);
  jwSerial.begin(9600);
  Serial.println("JW01 CO2 Sensor with Smoothing Ready");

  // initialize readings array
  for (int i = 0; i < NUM_SAMPLES; i++) readings[i] = 0;
}

void loop() {
  while (jwSerial.available()) {
    byte b = jwSerial.read();

    if (b == 0x2C) {   // start byte detected
      frame[0] = b;
      int i = 1;
      while (i < 6) {
        if (jwSerial.available()) {
          frame[i] = jwSerial.read();
          i++;
        }
      }

      // Decode CO2: B4 * 100 (based on your frames)
      int co2 = frame[3] * 100;

      // Save reading for smoothing
      readings[idx] = co2;
      idx++;
      if (idx >= NUM_SAMPLES) {
        idx = 0;
        filled = true;
      }

      // Compute moving average
      int sum = 0;
      int count = filled ? NUM_SAMPLES : idx;
      for (int j = 0; j < count; j++) sum += readings[j];
      int co2_avg = sum / count;

      // Print raw and smoothed CO2
      Serial.print("Raw CO2: ");
      Serial.print(co2);
      Serial.print(" ppm, Smoothed CO2: ");
      Serial.print(co2_avg);
      Serial.println(" ppm");
    }
  }
}