Differences between node-dht-sensor and Adafruir CircuitPython

[pfassberg]

Hi,

I'm testing a DHT22 on a RPi 4.

It works well using both the example code from node-dht-sensor and Adafruit CircuitPython.

However, after a number of iteration I found out that Python almost always give me a higher humidity than Node.

After a number of iterations using Python the first iteration using Node is showing a "Python high" humidity value, but the following iterations if showing a lower value. It is easily reproducible.

Any hints on why there at all may be a difference?

This is the code snippets:

var sensor = require("node-dht-sensor");
 
sensor.read(22, 4, function(err, temperature, humidity) {
  if (!err) {
    console.log(`temp: ${temperature}°C, humidity: ${humidity}%`);
  }
});

import adafruit_dht
from board import *

# GPIO17
SENSOR_PIN = D4

dht22 = adafruit_dht.DHT22(SENSOR_PIN, use_pulseio=False)

temperature = dht22.temperature
humidity = dht22.humidity

print(f"Humidity= {humidity:.2f}")
print(f"Temperature= {temperature:.2f}°C")