DHT22 | Program to read DHT22 sensor from the Raspberry Pi

The script is running fine in thonny on the rasperry zero and does its job to measure and interact with the mqtt server. This is intended to be a script that runs in the background and I added it to /etc/rc.local between the lines fi and exit 0: python3 /home/pi/pisensor/scripts/dht22_mqtt.py & After rebooting the expected messages on the mqtt server did not appear, so I tried running the script on the console. I called it with python3 dht22_mqtt.py in the directory and after some seconds it just looked like it was finished (new line in in console), but had done nothing (no messages to mqtt server and no print messages). No errors were shown that a library is missing or something was wrong. Could it be there is a problem with running an async script like this from console?

Is there a possibility to debug the script when run from console? I tried the -d parameter of python3, but with the same result. I tried pip3 with the dht and the paho-mqtt lib, but it was already installed.

You can have a look at the script here:

I've been playing with ESP8266 and achieved some good-looking readings via DHT22 and BH1780 sensors to a single HTML page where I can only use HTML, CSS and JavaScript for the frontend. Short story I read the temperature humidity and the light intensity in the tent, where light intensity is mainly to determine if is day or night for example LUX = 0 is night and LUX = 1 is day

My question: How and what to use in order to change each

For example, if Temperature readings exceeds 50 degree alert-danger...

Any suggestions welcome, but please note We can't use PHP :(

I have a Flask setup in my Raspberry Pi 4 Model B via this tutorial.

OS = Ubuntu Server 20.04.2 LTS
Python = 3.8

Please keep in mind that I am using virtual env for my Flask application as shown in the tutorial and my Flask application is running absolutely fine.

Now I installed Adafruit_DHT in the same venv and tried using the following code in one of the endpoints

I am getting started with electronics and microcontrollers programming.

I have made a simple circuit where I use DHT22 sensor to measure temperature and humidity. I have also made my own API in Node and Express (MongoDB as a database). It is very simple API, just two endpoints: one for getting. and one for posting data. I ma able to create succesfull requests using Postman (and with the browser).

Just to be clear, I want to send temperature and humidity to my API, and then do some work with this data on Vue website (I think that this is not relevant at all, but again, just to be clear what I am trying to achieve).

Now I will say what I am using:

Windows 10 OS NodeMCU ESP32 microcontroller DHT22 sensor HTTPClient library (I think this one is causing a problem) PlatformIO with Arduino.h header file Everything is ok, but when I try to send data to my database things fail. I am ALWAYS getting following error

[e][wifigeneric.cpp:739] hostbyname(): dns failed

I have tried to make the POST request using both http://localhost:3000/endpoint and http://127.0.0.1/endpoint (that part is really strange, why I am getting DNS error when using IP address without domain name?).

I have already looked up for the solution on the web. I have come across many similar questions on github, but any of them worked for me). Also, none of them were solving error caused by line 739.

Here I will leave my code. Is is simple and short, so I will post all of it. Please, do not blame me for my c++ skills, I am getting better :D

Thank you in advance, have a nice day or evening.

Kind regards, Bartek.

I've got a problem with a current project that aims to transmit data from a sensor to a platform in real time. It is a DHT22 sensor which is able to measure temperature and humidity. The idea was to save the data in a csv file and then send it to the platform using another script (sending the data from the csv file to the platform has always worked). The problem is that the data is stored in the csv file, but only in intervals of about 15 minutes and always in blocks of 800. The real-time aspect therefore does not come into play.

I used the following script to save the data as a csv file:

Have integrated Raspberry pi4 with a DHT sensor. The data pin is connected to pin GPIO 26

Have tried connecting the VCC to both 3.3V and 5V

Have tried with both Adafruit_DHT.DHT11 and Adafruit_DHT.DHT22 in the code for the same sensor but I get None None

I'm trying to read multiple sensors and saving all that data in one, singular, *.txt file. This is needed to enable it to analize and easily fill a database. But here is the catch, not all the sensors give int values, and as I learned the hard way, "String" gives to much unpredictable errors.

I want to read:

• Temperature
• Humidity
• Light intensity
• Sound

all saved as int
I also want to save

• 2 Accelero values (x,yand z values) as Float;
• a piece of text, just to log a status or debug as a String.

I tried to fill them into array but I'm overlooking something. Can someone please point me in the correct direction to make it work, that would help me alot!

For your interest, it should become a datalogger for a trailer for horses. So I get feedback about forces while driving and also the climate of the trailer and trigger camera and sound to monitor the animals (will be next step to livestream it and make it a IOT-system).

The code:

I am testing IoT sensors which each send temperature readings to a QuestDB instance, I'm using a basic TCP socket connection in Python to send it like the following: