Can the SV07+ accept a smart filament sensor?

I’m thinking of upgrading the stock sensor to a smart sensor, one that can detect filament motion. The standard sensor only has wires, but the smart sensors use 4.

Yes you could by several ways to do it.

  1. If you leave the sensor in the original location then connect only the movement sensor to the original pins. Change printer.cfg to reflect it is a movement sensor. On runout the printer will not stop instantly but keep going until 8 to 10mm more filament is used then stop. No worries there is 200mm+ filament left.
  2. Connect the motion sensor to the open shutdown module pin on the mainboard. You’ll have to trace the connection to the chip as I can’t find a pinout.
  3. Get a Raspberry Pi Pico, flash it with klipper firmware and attach the 2 switches to GPIO pins. Then add the Pico to printer.cfg as [runout_mcu]. You’ll have to modify printer.cfg to use the Pico.

Option 1 seems the best to me.