Research and Lab

Based on the data sheet, the sensing angle on the x axis of the sensor is 0 - 120 degrees; on the Y axis is 0 - 100 degrees. During the lab, the sensor reacted when our motions were in the range as stated.

The minimum sensing distance is 0 ft, regardless of the level of sensitivity. The maximum sensing distance we tested is about 3 ft, when the value of the potentiometer is set to minimum. When the value of the potentiometer is set from the middle to the highest value, which is about 500 to 1023, the level of sensitivity remains the same. The higher the value of the potentiometer, the less sensitive the sensor (lower distance).

We were able to change the length of time the signal pin stays high by connecting a potentiometer. In this case, we used a slider, which makes it easier to control. When the value from the potentiometer is set to around 5, the on time is about 3 seconds. When the value is set to around 70, the on time is about 7 seconds. When the value is set to around 120, the on time goes up to around 14 seconds. The higher the value of the potentiometer, the longer the on time for the sensor.

The strength of this particular sensor:

• the honeycomb shape allows the sensor to detect multi-directional movement

• it is easy to connect and work with Arduino

• it is light and small. Easy to carry

• it can be quite accurate and it is able to detect the movement precisely with the correct settings

The weakness of this particular sensor:

• the quality is not the best among all the PIR sensors

• the sensor cannot measure distance only. one has to move if one wants to measure distance

• it only takes 3.3V. some other more advanced PIR sensors can take higher voltage therefore they have wider applications

The workability of the sensor depends on its signal-to-noise ratio and fresnel lens. The temperature of the moving body, the temperature and humidity of the environment, and the electromagnetic interference also affect the sensor.

Existing applications of the sensor:

• electronic applications: toy, doorbell, tv, refrigerator, air-condition, digital photo frame

• smart home & security applications: USB alarm, intrusion detection, network camera, car alarm system, robot vacuums

• lighting applications: automatic lighting of indoors, courtyards, corridors, staircase lights, etc.

Ideas of applications inspired by the research and the lab:

• interactive art work in the museum or exhibition

• automatic watering when humidity or temperature change is detected

• lights on the road for the cars at night

• self-driving assistance