Witness Camera

The Witness Camera is an automated, self-recording surveillance camera, that uses a gigabyte-class flash card as recording media.

I designed the Witnesscam because available surveillance solutions were too expensive or impractical for home use.

I built the system from a VGA CMOS colour camera, a passive-infrared (PIR) movement sensor, an ATmega32 processor, and a 1GB SD-card.

The prototype looks like an ordinary alarm detector. But when it detects people moving around, it silently starts recording.

A 1 GB card can store 50,000 colour frames, with a definition similar to industrial VHS-CCTV recorders (320×200), taking a new picture every 2.5 or 3 seconds. On most typical domestic environments, this translates to more than one month of images before overwriting the oldest frames.

The Witness Camera features also a high resolution mode, taking pictures at 640×480 pixels every 3.5 or 4 seconds. Thanks to embedded image compression, the same card can contain as much as 25,000 frames when high-resolution is selected.

The recording system is flexible, allowing to choose between PIR activated, timer, continuous and externally triggered recording modes. You can decide what intervals to use and how many extra frames to take after a trigger ends.

Creating new applications, like an automatic door capable of taking snapshots of persons entering a building, or using it as an in-vehicle recorder, is simply a matter of selecting the operating mode and connecting a trigger source.

The system supports a standard file system (FAT16 or FAT32), and image compression format (JPEG). It sorts the pictures in an human-readable structure, grouping them in folders according by date and time.

Therefore, in the unlikely event you need to inspect the pictures, just take off the card from the camera and put it into a PC. No special software is required other than Windows XP default browser.

Source: Alberto Ricci Bitti – AVR2006/Winner Grand Prize

Download : Witness Camera

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