Here's how i shut down the OV3660 lens....

  // Put Camera Module into Standby Mode
  sensor_t * s = esp_camera_sensor_get();
  

      s->set_reg(s,0x3008,0xff,0x01);//banksel --- ? Is this needed for ov3660? Is there only 1 bank
      delay(100);
      s->set_reg(s,0x3008,0xff,0x80);//reset (we do this to clear the sensor registries, it seems to get more consistent images this way)
      delay(100);
      s->set_reg(s,0x3008,0xff,0x40); //stand by  (sensor, register, mask, value) 
      delay(100);

I reboot the camera to turn the lens back on.. .but there are registry setting that can be invoked to restart the camera module. see Omnivision OV3360 spec for registry settings.

Hi Jaz, I've been using OV2640 lens module with an 8" ribbon w/o any issues. The OV3660 is very similar in power usage.... Breakout board is probably causing you problems. I contacted a manufacturer in China. They made a special 8" mold for me to create the 8" OV2640. I've purchased almost 50 of the 8" lenses and have had no performance issues. I have not asked them to create an OV3660 8" yet.....

@rtrias I'm having the same problem. I'm using the USB port to power the Timer Camera and cannot determine how to turn off the camera (or even the lens). The lens gets extremely HOT and I'm afraid of a fire hazard.

I'm using USB Power, Deep Sleep w/ GPIO Awakening
? How do I shut-down the lens module ?

Tried to put the Timer Camera into Deep Sleep. The lens still gets very HOT.