MQTT Cayenne connection using RaspberryPi4 and automated startup

Community Help With My Project
1

Good morning Cayenne-fellows,

The manual connection over MQTT to cayenne works perfectly (manual=python script executed in shell)
I’ve been trying for some time to get a python script executed automatically at startup and followed this nice tutorial:

I’ve tried all methods excluding the init.d-variant. Adding a service or using crontab looked like the best options to me.
So for example what I did for adding the auto startup is:

crontab -e
@reboot sudo python3 /home/pi/Desktop/pyprog/pytest.py > /home/pi/Desktop/pyprog/log.txt
crontab -l showed that the cronjob is running

The script connects to MQTT-Cayenne:

I see that there is one successful connection over Cayenne but then the RPI loses connection again. When i execute the script using python3 myscript.py it works fine.

I have also tried adding a sleep time of 30-120seconds to wait for internet connection to establish and used & to rund the process in the background.

Have you got an idea on how to troubleshoot this? The project involves three parts: RPI with cronjob, python3 and mqtt-cayenne.

Thank you!

I have used following library:

2

DHT11/DHT22 with Raspberry Pi in this topic it shown all to add run the file at reboot

3

Thank you Shramik, I have followed that tutorial and also tried the cronjob method. The script is executed (with and without the &) just once after the startup and a single MQTT connection is established with message upload. Shortly after, the connection is offline again and stays offline.

Do I need to specifiy something in the preamble of the python script?

4

can you share your python script

5

Have you tried running the script manually? Sounds like it’s not looping correctly. As Shramik said, share the code.

1 Like
6

Solution for me: just create a .desktop file:
https://learn.sparkfun.com/tutorials/how-to-run-a-raspberry-pi-program-on-startup/method-2-autostart

and select the wait for network option from the raspberry pi settings menu.

7

thanks for sharing the solution.