Ytdyklly

I'm running a telegram bot on my Raspberry Pi 3. When I run it in my console or using Thonny, everything runs smoothly.

python3 /home/pi/Documents/telegrambot.py

The problem occurs when I set the program to start on boot.

sudo crontab -e

[last line] @reboot sudo python3 /home/pi/Documents/telegrambot.py &

I know that the code is running because I set the bot to send me "I'm online" and it answer me if the reply isn't related to sending images... but when I send to it /tempgraph, it should answer with the the picture of its readings.
But I only get the sensor's name and no image at all.

...

    chatHist = readCommandHistory(db,chat_id,1)

    lastCommand = chatHist[0]['msg']

    choice = command.split(".")

    if command in lastCommand and len(choice) <= 2:

        Fonte = re.search('(s|n)'+str(command.split('.')[0])+')s(.*)', lastCommand).group(2)

        bot.sendMessage(chat_id, Fonte) #this works

        if len(choice) == 1:

            table = sdc.readTableServer(db, senstable, 'Fonte', Fonte)

            for sensor in table.Sensor.unique():

                bot.sendMessage(chat_id, sensor) 

                tbl = table[table.Sensor == sensor]

                #until here everything is ok

                for ts in tiposensores:

                    try:

                        gop.plotSetup(tbl[['Data',ts]]) 

                        #save the image in the folter ... Images/Imagem.png, 

                        #but only works when not on stratup...

                        bot.sendPhoto(chat_id,open('/home/pi/Documents/Images/Imagem.png','rb'))

                        pif.cleanImages()

                    except OSError:

                        pass

...

@edit:

I found out that the problem happens after i call

gop.plotSetup(tbl[['Data',ts]]) 

inside the plotSetup function, in this step:

f= plt.figure(figsize=(12, 9))

This is the first time that i use the variable f inside the function.

Try this:

$ sudo chmod 777 /home/pi/Documents/Images 

After you've done that, re-boot to check if that fixes it.

If not, try changing your crontab entry to this:

@reboot ( /bin/sleep 30; /usr/bin/sudo /usr/bin/python3 /home/pi/Documents/telegrambot.py >> /home/pi/Desktop/log.txt 2>&1)

You should also consider adding a debug statement to your Python code to collect and save any errors that are thrown during execution.

This might be a permission problem. When running under the user's (your) credentials it works and when under the crontab's credentials is does not.

Try a test: WRT to your images, temporarily open permissions to all images files and the associated directory and see if the application works when run by the crontab.

Don't leave the permissions opened to all as it is a security risk.