I remember reading somewhere that the DHT 11 was not compatible with the pi 5, but the 22 was supposed to work. I have no problems using the sensors on an old 3b+. My question has anyone got the DHT22 to work in node red on a pi5? I also know that most people don't like them because of all the problems like this, so what is a better alternative to use for temp and humidity in node red?
There are quite a few i2C sensors to choose from e.g. BMP280 or SHT31.
Alternatively you can connect your sensors to an ESP such as a D1 Mini running Tasmota or similar, and send messages back to your Pi via MQTT.
There are a wealth of different types of sensors supported, so no need to try and find NR nodes for a particular sensor that way.
It's also a safer option than wiring directly to the GPIO header.
EDIT: you could also keep using your DHT11 with an ESP 
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Yup.
God forbid that you accidentally touch the wrong GPIO pin and your shiny new Pi expires.
Use an ESP and MQTT
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I use Sonoff Zigbee SNZB-02 sensors for temperature and humidity. I don't know how accurate the humidity reading is as I have nothing to compare them with.
I always use a breakout board with screw terminals. I have a couple esp32s but i haven't ever used MQTT. I know very little about it.
I don't doubt that can work fine, though I have seen a few posts here reporting GPIO related problems on the Pi 5, or maybe just with RPiOS Bookworm in general.
I use BME280 & BME680 sensors attached to ESP32 boards. My ESPs run Tasmota, though some prefer a different firmware, and report the sensor values every few minutes using MQTT over wifi. It's basically automatic once the sensor is wired up.
Here is an example payload, very simple to access in Node-red.
{
"Temperature":16.3,
"Humidity":69.8,
"DewPoint":10.7,
"Pressure":982.8,
"SeaPressure":999.8,
"Gas":129.31
}
I agree with the comments above - if you have an ESP32-S2-Mini then use that as a remote sensing node (rather than risk damaging your expensive RPi-5).
For the last 3+years I've been flashing my devices with Micro-Python using Thonny as when I pick-up an ESP32-S2-Mini I can plug it in to a USB socket and "see" what is on the device.
As an example this morning, I've very quickly wired an ESP32 and BME280 on a breadboard...
And created the following Micro-Python script to read the sensor at regular intervals and send the readings, via a MQTT structured report, to Node-RED.
Note: The script makes use of the Micro-Python libraries 'umqtt.simple' and 'bme280' which need to be located in the 'lib' folder in the ESP32 (after it has been flashed with Micro-Python).
Using this simple Node-RED flow...
I get this reported using a Debug node...
When I have some spare time, I'll write a detailed tutorial of the steps involved and post it on 'Share Your Projects'.
'''
Demo script for ESP32-S2-Mini fitted with BME280 sensor
MQTT publish topic is: "home/sensor/bme280"
Last edited 23/March/2025
'''
import machine, network, math
import utime, ujson, ubinascii
# Import MicroPython libraries
from umqtt.simple import MQTTClient
from bme280 import BME280
# Wi-Fi Configuration
WIFI_SSID = "your_wifi_ssid"
WIFI_PASSWORD = "your_wifi_password"
# MQTT Configuration
MQTT_BROKER = "your_mqtt_broker_ip"
MQTT_PORT = 1883
MQTT_TOPIC = "home/sensor/bme280"
CLIENT_ID = ubinascii.hexlify(machine.unique_id()).decode()
# Alias classes for convenience
Pin = machine.Pin
SoftI2C = machine.SoftI2C
# Constants
BME_ADDRESS = 0x76
REPORT_INTERVAL = 10 # Seconds between sensor readings
RECONNECT_DELAY = 5 # Seconds to wait before reconnecting Wi-Fi/MQTT
# Create an I2C instance on the microcontroller
i2c = SoftI2C(scl=Pin(35), sda=Pin(33))
# Wi-Fi Connection Function with Auto-Retry
def connect_wifi():
wlan = network.WLAN(network.STA_IF)
wlan.active(True)
print("Connecting to Wi-Fi...")
wlan.connect(WIFI_SSID, WIFI_PASSWORD)
for _ in range(20): # Try for ~20 seconds
if wlan.isconnected():
print("Wi-Fi connected:", wlan.ifconfig())
return True
utime.sleep(1)
print("Wi-Fi connection failed. Status:", wlan.status())
return False
# MQTT Client Setup with Auto-Reconnect
def setup_mqtt():
while True:
try:
client = MQTTClient(CLIENT_ID, MQTT_BROKER, MQTT_PORT)
client.connect()
print("Connected to MQTT broker\n")
return client
except OSError as e:
print("MQTT connection failed:", e)
print(f"Retrying in {RECONNECT_DELAY} seconds...")
utime.sleep(RECONNECT_DELAY)
# MQTT Publish Function
def publish_mqtt(client, data):
try:
client.publish(MQTT_TOPIC, data)
print("Published:", data)
except Exception as e:
print("Failed to publish:", e)
# Read BME280 Sensor
def read_bme280(bme):
try:
temp = round(float(bme.values[0][:-1]), 1) # Round to 1 decimal
humidity = int(float(bme.values[2][:-1])) # Convert to integer
pressure = int(float(bme.values[1][:-3])) # Convert to integer
return {
"temperature": temp,
"humidity": humidity,
"pressure": pressure
}
except (ValueError, IndexError) as e:
print("BME280 read error:", e)
return None # Return None on failure
# Main Function with Connection Handling
def main():
while not connect_wifi():
print(f"Retrying Wi-Fi in {RECONNECT_DELAY} seconds...")
utime.sleep(RECONNECT_DELAY)
client = setup_mqtt()
bme = BME280(i2c=i2c, address=BME_ADDRESS)
while True:
try:
sensor_readings = read_bme280(bme)
if sensor_readings:
json_data = ujson.dumps({
"report": "BME280 readings",
"temperature": sensor_readings["temperature"],
"humidity": sensor_readings["humidity"],
"pressure": sensor_readings["pressure"]
})
publish_mqtt(client, json_data)
else:
print("Skipping publish due to sensor read error")
except OSError: # Handles Wi-Fi/MQTT failures
print("Network error, reconnecting...")
utime.sleep(RECONNECT_DELAY)
client = setup_mqtt() # Reconnect MQTT
except Exception as e:
print("Error in main loop:", e)
for _ in range(REPORT_INTERVAL): # Sub-sleeps to allow interrupts
utime.sleep(1)
# Run the script
main()
If you create more than one remote sensing node, you can identify which one has reported its readings by altering the MQTT topic entry in the Micro-Python script.
e.g. MQTT_TOPIC = "home/kitchen_sensor2/bme280"
Or insert an entry (labelled 'location') in the structured report as follows.
json_data = ujson.dumps({
"report": "BME280 readings",
"location": "kitchen",
"temperature": sensor_readings["temperature"],
"humidity": sensor_readings["humidity"],
"pressure": sensor_readings["pressure"]
})
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Looking forward to that Dave!
I hope you will include flashing the ESP with micropython.
I notice that your Python code does not include an adjustment for elevation to the BME's absolute pressure readings. Did you consider adding that? (it's not a completely trivial calculation).
Tasmota does report both absolute and sea level pressure as long as you tell it the elevation. I have not tracked that calculation down in the Tasmota source.
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Thanks for your comments and technical observations.
My objective this morning was to write something that was quick and simple.
Yes, thank you so much I'm still trying to figure out the esp32 programming. I did get it to show temp and humidity. And I have a MQTT server running on my windows 2016 server now. and its working between the pi and windows server, however getting the esp to connect is a different story.
Umm. Raspberry Pi, Mosquitto.
I expect it will work on Windows, but should it?
It's a "broker", not a "server" 
is there an issue with it being on my windows server?
I am sure there is no problem with having a broker on Windows.
For me, my Windows PC is turned on and off as I'm using it,or at least sleeping.
An mqtt broker is probably best running 24/7, and I know that mosquitto works very well on a Pi.
