555 Contest Entry: Motion activated camera
![](https://embedded-lab.com/blog/wp-content/uploads/2011/02/555_PIR_monostable.jpg)
This entry for the 555 timer contest is from Andrew Smith who built a motion activated switch for a digital camera. The 555 timer is operating in monostable mode which is triggered by a PIR sensor when motion is detected. The monostable output of 555 then activates the camera through a remote.