Singapore is a humid country and to keep ourselves cool we use fans or air-conditioning. However, we do not use the most energy efficient settings sometimes we set the mode too cold or set the fan to high then proceed to wear a jacket which is not economical in the long run. to combat this I wanted to design an appropriate device to sense how far You are from the fan or air conditioning unit to calculate the appropriate setting for fan speed for better economic benefit as well as ecological benefit. This project was made of assessment for a module in Singapore Polytechnic. Feel free to learn and use my project or maybe integrate part of this project or code with yours.
Tip110, Arduino Uno, Servo, Dc motor, wires (preferably jumper or single core wire ), copper stripboard, Diode.male-female standoff connectors
Step 1: Schemetics and Design
I used an Arduino UNO, HC-SR04,tip110 power transistor, a servo actuator, a 3v dc motor and a diode. my design has the Hc-sr04 ultrasonic sensor always tracking for the user . to do that I designed a module for the ultrasonic sensor to be put on the servo so that it has 180 degrees of angle view. I have uploaded the fritzing schematic with this step.Fritzing is an open-source hardware initiative that makes electronics accessible as a creative material for anyone. We offer a software tool, a community website and services in the spirit of Processing and Arduino, fostering a creative ecosystem that allows users to document their prototypes, share them with others, teach electronics in a classroom, and layout and manufacture professional pcbs(To download fritzing go to http://fritzing.org/download/). I used fritzing as it is open source and meant for the Arduino community .
Step 2: Module Making
I then made the modular copper stripboard to be placed on the Arduino .it has male-female standoff connectors to be able to be modular in case there is more to be added in the future. after that, I glued the servo down and then attached the servo onto the copper stripboard. I made a module for the ultrasonic sensor to be placed in using balsa wood but u may use whatever scrap materials such as cardboard to make yours
Step 3: Assembly
I followed the schematic I made and connected the wires and soldered them accordingly on the stripboard .trigger pin connects to pin 9, the echo pin connects to pin 10, the servo signal pin connects to pin 11.the pin 6 is a PWM pin which is connected to the base of the tip 110 power transistor the collector is soldered to VCC in my case the 5v pin of the Arduino and the motor I soldered to the emitter pin of the tip 110 and the ground(NOTE: if you are using a secondary circuit example the motor has separate power make sure You connect the ground to Arduino ground to have a common ground if not your motor won't work.)solder the diode between the motor and the emitter the current flow should be towards ground so the line on the diode must face the direction of current . PWM works by pulsating DC current, and varying the amount of time that each pulse stays ‘on’ to control the amount of current that flows to a device such as a motor. PWM is digital, which means that it has two states: on and off (which correspond to 1 and 0 in the binary context, which will become more relevant to you if using microcontrollers https://www.kompulsa.com/introduction-pwm-pulse-width-modulation-works/). Basically, the motor is being switched on-off specific times to control the speed just that it happens so fast we can't see. after that just attach the ultrasonic module to the servo.
Step 4: Testing of Codes
I started by coding the ultrasonic sensor then the servo motor. after that, I coded the if else statements for the motor. I used object-oriented coding for my project separating the codes for easy debugging. I have uploaded the code files with this step if you would like to view it.
Step 5: Demo of the Project
Demo of the project. IT works :) Hopefully, You learnt something from my project. this is just a small scale prototype but u can edit the code and add an ir module to remotely control the fan in your living room.