An auto on/off fan was built based on a temperature sensor, two motion sensors, a fan, and a servo. The fan turns on when the ambient temperature reaches a certain degree. The motion sensors are used to track a person’s movement which then the servo will rotate the fan toward that movement accordingly.
A microcontroller was used to control the overall operation of this fan. A program has been written and downloaded into the microcontroller to control the temperature for powering on/off, and to control the degree of rotation of the servo as it receives signals from the motion sensors.
The temperature sensor and the motion sensors send out a voltage to the microcontroller which then we regulated so that it would not overload the microcontroller. These voltages are then used as signals for giving commands to the microcontroller. Then, the microcontroller, which is also connected to the fan and the servo, sends out voltages(signals) back to the fan and servo allowing it to power on and off. The fan turns on only when there is a signal sent to the fan.
From this project, we learned the difficulty in programming the microcontroller, the time and effort professional engineers spent on producing a quality satisfactory product. When programming the microcontroller, we encountered many problems such as debugging, setting the servo to run, letting the motion sensor to run smoothly, and etc. In addition, we learned more about servos, sensors, and other mechanical interfacing devices.
Source: San Jose State University
Author: Yan Kin Chan | Peter Vuong | Andy Yip | Saurabh Gupta
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