Sentinel Network

By Ruibing Wang

The Sentinel Network is a sensor network intended for outdoor usage to detect the presence of
trespassers in restricted, private areas. Multiple sensor nodes wirelessly communicate with a base node,
extended through a relay node if necessary, to alert the user through an UI that a unique identified
sensor node has been tripped.

In order to fulfill its solution as a low cost, low maintenance sensor network that is scalable to the needs
of the user, the Sentinel Network was designed to be as easy to use as possible. Sensor and relay nodes
can be easily added (or appended) to the network topology without requiring any firmware upgrades or
changes. The process of monitoring the Sentinel Network was also simplified through the supplied UI for
the user to access, monitor, and debug the Sentinel Network on any PC. Every sensor and relay node
was also designed to run for a minimum of a year through solar powered daytime operation with a AA
battery proving backup power during lowlight seasons and conditions. The network protocol was also
designed to be as robust as possible with automatic CRC, CSMA-CA, frame acknowledgement, and
address filtering. Finally, every sensor is paired with a PIR sensor to detect moving trespassers.

The Sentinel Network provides a complete solution to detecting trespassers in remote areas. While the
main focus is its ability as a PIR sensor network, it is, in fact, a network platform. Any sensor or data
input can be attached on the sensor nodes to be relayed to the base node. With a small amount of
modifications, it can even serve as a tracking system for the sensor node.

Full report (pdf) and docx

Source code