I have got a defects subtracted image using python and openCV. Now I want to send a digital signal to an actuator to take necessary actions when a defect is detected. How can I do that? I wish to use raspberry pi for this project.
First it seems to me that you can use Arduino or Raspberry pi for this task. Also i suggest you to see links and attached files, you will be able to inspired you for solving your problem.
-Three Hundred and Sixty Degree Real-Time Monitoring of 3-D Printing ...
www.mdpi.com/2504-4494/1/1/2/htm
-Closed loop control of slippage during filament transport in molten ...
If your "digital signal" is just a 1/0 decision, the GPIO pins of the RPi are next to perfect. They might eventually need amplification and/or level shifting, which is easily achieved by using one of the "shields"/"hats" available.
if you want to use Raspberry, just use the python GPIO library, which will allow you to manipulate the IO of the board, and to transmit the digital signal to the desired device.