Description
HT12E is a 212 series encoder IC (Integrated Circuit) for remote control applications. It is commonly used for radio frequency (RF) applications. By using the paired HT12E encoder and HT12D decoder we can easily transmit and receive 12 bits of parallel data serial. HT12E simply converts 12 bit parallel data in to a serial output which can be transmitted through a RF transmitter. These 12 bit parallel data is divided in to 8 address bits and 4 data bits. By using these address pins we can provide 8 bit security code for data transmission and multiple receivers may be addressed using the same transmitter.
 
PIN DESCRIPTION OF IC HT12E: 
The pin Description of the IC HT12E was pretty simple to understand with total of 18 pins. 
VDD and VSS: Positive and negative power supply pins.
OSC1 and OSC2: Input and output pins of the internal oscillator present inside the IC.
TE: This pin is used for enabling the transmission, a low signal in this pin will enable the transmission of data bits.
A0 – A7: These are the input address pins used for secured transmission of this data. These pins can be connected to VSS for low signal or left open for high state.
AD0 – AD3: This pins are feeding data into the the IC. These pins may be connected to VSS for sending LOW since it is a active low pin
DOUT: The output of the encoder can be obtained through  this pin and can be connected to the RF transmitter.