13.2.2. Running the script

The Viewer runs a product’s script rather than one you are editing. The start button – the green arrow below the connect button, or Ctrl+R – runs the script; while it runs, the start button becomes a stop button that halts it. A script can be handed to the Viewer on the command line so it starts running the moment a camera connects, which is the usual way to point the Viewer at a finished application.

While a script runs, its print() output streams into the serial terminal and every frame it captures appears in the frame buffer viewer. That is the whole point of the Viewer: connect a camera, run the product’s script, and watch it work.

The related Tools → Stop Script on Connect/Disconnect option (on by default) halts the running script when the Viewer attaches or detaches, so a camera is always left in a known state. A camera also keeps running whatever script is stored on it as main.py when it has power, with or without the Viewer attached – connecting simply lets you watch it.