Take timelapse with Raspberry Pi and unstable webcam

reset_webcam

#!/bin/sh
# https://gist.github.com/x2q/5124616#file-usbreset-c-L41
/usr/bin/usbreset /dev/bus/usb/001/002

sudo

pi ALL = (ALL) ALL
pi ALL = (root) NOPASSWD: /usr/bin/reset_webcam

timelapse.sh

#!/bin/sh
while true; do
  echo "Taking screenshot..."
  prefix=`date +"img-%Y-%m-%d_%H-%M-%S.jpg"`

  fswebcam -r 1280x720 --no-banner $prefix
  sudo /usr/bin/reset_webcam
  sleep 60
done