Wireless Doorbell Calling System

Traditional Doorbells are wired devices and are usually fixed at one place. They are becoming obsolete because of these reasons and are gradually being replace by advanced Wireless Doorbell Devices. With a wireless doorbell, the position of the switch and the bell is not fixed. We can place it anywhere we want and also the installation is pretty simple. The setup of wireless doorbell doesn’t require any internal wiring. Also, if the wired doorbell is not fixed while construction, we need to make holes for wiring and installation. We have two units in this project which are connected to each other through an RF link. The transmitter unit has a button attached to it for user interface. When a user presses this switch it is indicated to the system that a bell should be rang inside the house / office premises. This information is passed on wirelessly to the receiver unit which has a hooter attached to it. This buzzer is pulled high by the system to hoot and thus signifying a visitor at the door. When the button is pressed at the transmitter side it alters the signal that is continuously sent by the transmitter side to the receiver side. When this altered change in the signal is received at the receiver, its voltage level at the respective pin goes high this triggering the hooter or the buzzer attached to that pin. This sound of the buzzer remains ON till the switch is pressed on the transmitting side. Thus we have an effective calling system which is simple enough and is also inexpensive.