HT12D decoder will be in standby mode initially ie, oscillator is disabled and a HIGH on DIN pin activates the oscillator. Thus the oscillator will be active when the decoder receives data transmitted by an encoder. The device starts decoding the input address and data. The decoder matches the received address three times continuously with the local address given to pin A0 – A7. If all matches, data bits are decoded and output pins D8 – D11 are activated. This valid data is indicated by making the pin VT (Valid Transmission) HIGH. This will continue till the address code becomes incorrect or no signal is received.
- Used to convert Parallel 4-bit data to series data
- Highly useful in wireless communication projects involving RF or IR
- Remote controlled systems like garage doors, Car alarm system, Car door controls etc.
- Can be used in Home automation for short range remote switching
- Safety systems like Burglar alarm system, Smoke or Fire alarm system etc..
Pin 1-8- Address Pins
Pin 9- Vss
Pin 10-13- Data Output Pins
Pin 14- Serial Data Input Pins
Pin 15 & 16- Oscillator
pin 17- Valid Transmission
Pin 18- Vcc