mousa

Many peoples forgets the Room lamps in running state when nobody in the room, this causes increasing electric bill or battery energy losing in solar home. This Arduino project is a visitor counter that turns OFF the lamp when nobody in the room automatically, it also can used for lamps of bathroom, toilet, kitchen, etc. Visitor counter can makes by using different types of sensors, such as IR ray, Ultrasonic, Avoidance sensor, Laser ray, etc. Here i used Laser because the laser has long distance range, Avoidance sensor is very easy to use but its distance rang is lower than 30cm. You can make this project with LCD display for showing the numbers of people in the room but as you can see in the video i don't used display because its not important for me, any way the code is same with or without display. This project help to power consumption optimizing.  Parts list: Arduino board  1 Channel Relay module Laser diode(2 pcs) Light sensor modules(2 pcs) Adapter 5v 200mA If you want to us

In this project i used Arduino and some other electronic components for AC mains frequency measurement. Since Frequency is equal to: 1 divided by time period, so in first we should measure the time period. Time Period is the time of one full wave in AC voltage, means positive half wave+negative half wave. Here i used optocoupler for detecting the frequency of AC voltage. 47K resistor decrease the current to about 5mA for running the optocoupler and one diode for half wave rectification  So the arduino here calculate the ON time and OFF time of optocoupler that connected to Pin 13 in arduino board, then divided 1 by ( ON+OFF ) Time for give the frequency.  Since in arduino code the time always must insert as millisecond so we devide 1000 by ON+OFF Time for give the frequency. The circuit 100% insulated from mains voltage and can not be harmful for your arduino board. You can use any other available optocoupler rather than 817B.  Parts list:  Arduino board LCD display 16x2 Resistor 10K R