• Home
  • Tutorials
  • Interviews
  • Info Seed
  • Forums
  • Projects
  • Links
  • Contact Us
Projects
PROJECT BASICS
POWER SUPPLY
RELAY
CURRENT BUFFER
BIDIRECTIONAL CURRENT BUFFER
PARALLEL PORT
LEVEL SHIFTER
WIRELESS COMMUNICATION
TX433 & RX 433
ENCODER (HT12E)
DECODER (HT12D)
Calculating the value of RESISTANCE
PROJECT IDEAS
 

 

 

ENCODER IC HT12E:

This IC is used in the remote control systems. The IC has N address pins (8<=N<12) and 12 – N DATA pins.(HOW AD PIN CAN BE USED AS ADDRESS PINS) The IC transmits the address & data together via an infrared or RF transmitter when the transmission enable signal is supplied. This is a 18 pin IC with the following pin diagram:

 

Pins 1-8 are the address bits. This 8bit address is sent along with the data and the data is accepted only at the receiver where address is same as the address of encoder.

Pin 9 is the Ground

Pin 10-13 are the address/data pins which we can use as DATA or extended ADDRESS pins. On the DATA pins we put the DATA to be transmitted.

Pin 14 is TRANSMIT ENABLE pin. The data is transmitted only when there is a LOW at this pin.

Pin 15-16 we need to connect a resistance between these pins and the value of resistance is dependant upon the voltage applied and the frequency of transmission which is described later on.

Pin 17 is the DATA OUT pin which is connected to the DATA pin of transmitter TX.

Pin 18 is the pin where we need to supply the voltage V.

NOTE: The ENCODER transmits the same address and the data 4 times for a proper single transmission. This is done just to ensure that data transmitted is received error free. The data is received 4 times and checked that there is no error in the transmission. If the 4 DATAS accepted at the receiver are not same then ERROR is reported at the receiver.

  

And working of the IC can be understood from the following flow chart:

We can see from the flow chart that same data is sent 4 times just to ensure data transmission is ERROR free.

 

 

 

 

previous next
| Copyright © 2009 exploreroots- All Rights Reserved | Disclaimer |