A PIR motion activated camera is typically deployed as a security measure to detect, record and identify an unauthorized intruder. Key design considerations of such a device include false alarm immunity, extended battery life, low BOM cost and small form factor.
A number of Atmel-based components can be used to build a PIR motion activated camera that follows the above-mentioned design requirements. Firstly, Atmel’s ARM-based (Cortex-M4) SAM4S16 is capable of achieving fast image capture along with compression, all while transferring the data back to the control center – thereby facilitating rapid visual verification and response.
“Perhaps most importantly, Atmel’s SAM4S16 offers low power operation to extend battery life, with embedded peripherals running independently from the CPU,” an Atmel engineering rep told Bits & Pieces.
“So that means PIR sensing and image capturing without CPU load. More specifically, single snapshot mode =>30uA/day -10 years of battery life (3V, 2800mAh Li-Ion).”
Similarly, Atmel’s 86RF212B/233RF transceiver offers low-power operation with Sleep Mode down to 0.02uA.
“Developers can also save on total BOM cost and reduce design form factor, as Atmel’s SAM4S16 is capable of independently handling image encoding and processing with software,” the engineering rep continued. “In addition, the Atmel-based design (SAM4S16) allows the removal of one external amplifier interfacing PIR Sensor via the embedded ADC with gain stage. Plus, the SAM4S16 directly connects to any CMOSImageSensor, all while providing color picture capture at QVGA resolution.”
On the software side, developers have easy access to the SAM4S evaluation kit (Xplained Pro), along with Atmel Studio, Gallery and free libraries, including FreeRTOS, TCP/IP Stacks and 802.15.4 Stacks.