Maybe a Queue could work for you? Link. Queues are FirstInFirstOut so you could have your threads putting stuff in it and then have, I don't know, a fourth thread that will be grabbing stuff from the queue as they come and write them to the file.
Hope this helps.
This is kind of a python question, but is dependent on the Pi specific RPi.GPIO.
The GPIO.PWM creates a thread which is responsible for the PWM operation.
This stores data in a structure, which is (eventually) destroyed when you call PWM.stop().
You don't do this, but it will happen when the variables are garbage collected on function exit.
Effectively the ...
If you search this Forum you will find MANY questions about DHT22.
The Adafruit code is notoriously unreliable and CAN NOT be run from PHP because it requires root access.
See Reliable temperature/humidity logging with Python and a DHT11 for the code I use.
The code Joan posted will work, but that does not mean the relays will.
These relay modules are unsuitable for the Pi as they are only controllable from 5V.
Attempting to run them risks damage to the Pi and they do not work reliably.
Can you use a 5V Relay Module with the Pi? describes these and suggests modifications to make them work.
In addition you could ...
See gpiozero OutputDevice.
RELAY_PIN = 4
# Triggered by the output pin going high: active_high=True
# Initially off: initial_value=False
relay = gpiozero.OutputDevice(RELAY_PIN, active_high=True, initial_value=False)
relay.off() # switch off
relay.on() # switch on
print(relay.value) # see if on or off
Here are some methods using my Python modules.
You can also use the Python smbus module.
pi = pigpio.pi()
h = pi.i2c_open(1, 0x78)
(b, d) = pi.i2c_read_device(h, 6)
print(d, d, d, d, d, d)
sbc = ...
My question is: How do I configure the pi so that i can plug it back in, it boots up itself and runs the program without having to use ssh or a keyboard and monitor to login.
You don't have to do anything to the RPi to have it start (boot) when power is connected - this is the way it works!
You can use cron to start a Python program upon startup - this is ...
check this link
this was helpful for me I could autostart qt application on a raspberry pi os lite so I think you can run your python program
you just need to create a .service file in the /etc/systemd/system
sudo nano application_one.service
I think (unless you have not corrected it yet) you have your wires wrong. The green one is the signal (data) and you have it connected to the 3V3.
Source: DFRobot - SEN0137 DHT22 Temperature and humidity module
Try running it in the loop like in the dht_simpletest.py - as @Milliways mentioned the python library is not stable.
Running in the loop and ...
Following on from @Techraf you need to install the geckodriver.
Here is the latest version supported for Rasp Pi:
This is the latest release supporting arm7hf, which I believe is required for Selenium on Rasp Pi.
You need to inform your script to load the ...