At last, an app with a GUI!

For a while, I have been turning the camera on the Pi in the greenhouse on and off manually. By that I mean…

• Connecting to the Pi using VNC
• Opening the /var/tmp directory in the file manager
• Creating a file called blind to switch the camera off, or
• Deleting/renaming the blind file to switch the camera on
• Disconnecting from the Pi

That’s clearly a huge faff, so I decided I’d finally make a GUI based program to do the job, using guizero. Other GUI libraries were either immensely complex or mysteriously impossible to install. I looked at a couple of example programs, and cobbled this together…

import paramiko
from guizero import App, Text, PushButton

def switch_camera_on():
    ssh_stdin, ssh_stdout, ssh_stderr = ssh.exec_command("sudo rm /var/tmp/blind")
    
def switch_camera_off():
    ssh_stdin, ssh_stdout, ssh_stderr = ssh.exec_command("touch /var/tmp/blind")

ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh.connect("server-name-here", username = "user-name-here", password = "password-here")

app = App(title="Greenhouse Camera Control", bg = "lightblue", width = 400, height = 200)
welcome_message = Text(app, text = "Click button to switch camera state.", size = 15)
onswitch  = PushButton(app, command = switch_camera_on,  text = "Camera on.")
offswitch = PushButton(app, command = switch_camera_off, text = "Camera off.")

app.display()

It does need you to have used ssh-keygen on your systems, so they can communicate. I can’t believe how easy simple stuff like this is to hack out!