I have an embedded linux system that I need to run a python script whenever it boots. The python script needs to have a terminal interface so the user can interact and see outputs. The script also spawns another process to transfer large amounts of data over SPI, this was written in C.
I've managed to get the script to start on launch and have terminal access by adding
@reboot /usr/bin/screen -d -m python3 /scripts/my_script.py
to the crontab. I can then do "screen -r" and interact with the script. However if launched in this way the script fails to start the external SPI script. In python I launch the script with subprocess.Popen
proc=subprocess.Popen(["./spi_newpins,"-o","/media/SD/"+ latest_file"])
and this works perfectly whenever I manually launch the script, even within screen. Just not when it is launched by crontab. Does anyone have any ideas on how to get the spi subprocess to also work from crontab?
Fixed now, I had to add an absolute path to the spi_newpins function call
proc=subprocess.Popen(["/scripts/./spi_newpins","-o","/media/SD/"+ latest_file"])
Embedded linux start python from crontab with terminal access and subprocess permissions