RF Communication has been present since Nikola Tesla invented it.It has become more digitzed and more efficient to use.The most simple is remote control cars.Today i would be telling how remote control cars started in the first place.
Encoders and Decoders form the very root of Digital electronics.They are also used in RF Communication till today.They are effective and simple to use.they involve pushbuttons,dip switches and 5v supply thats all.
Today i would be talking abt the famous RF Encoder/Decoder(HT12E&HT12D) Pair.
So as we know 8 bit communication has 256 possible combinations (2^N bits)
So for now instead of complicating stuff connect ground to pins 1 to 8.
So pins 10 to 13 are the input pins.(Active LOW)
These are usually connected to pushbuttons.
For now we just put pin 10 to a switch.
Pin 11 to Pin 13 to VCC .
Pin 14 must be grounded to transmit the signals
The HT12E Resistor between pin 15 and 16 is important as without it there wont be any data sent
to the RF transmitter.
It must be 20 times the resistor value of HT12D.
We are using a 1.1Mohm Resistor.
Pin 17(Data Pin)
Pin 18(VCC)
RF Module FS1000A (Best RF Module in my opinion)
Here is the schematic diagram
Ok so for the receiver part to receive signals from the transmitter they must be in sync.So to be in sync it is important that Pins 0 to Pin 8 matches the address u have allocated for HT12D.So in this case connect them to ground.
The only output pin thats important is pin 0 since its the only pin we are using on the HT12E side.
Pin 14 is connected with the output of the RF Receiver.Pin 15 to Pin 16 resistor value shd be 51kohm.
Pin 17 is the Valid Transmission pin.So to see if the RF TX is working connect to a 100ohm resistor then to an led then to grd.If its working the LED shd light up.Pin 9 and Pin 18 to gnd and vcc respectively.
This is the schematic diagram
Power Supply
To transmit longer distances more voltage supply is needed so max voltage for the RF TX is 12v .
The RF receiver is not 9v/12v its a typo its 5V.
Antenna
Attach an external antenna
http://en.wikipedia.org/wiki/Rf_module
Encoders and Decoders form the very root of Digital electronics.They are also used in RF Communication till today.They are effective and simple to use.they involve pushbuttons,dip switches and 5v supply thats all.
Today i would be talking abt the famous RF Encoder/Decoder(HT12E&HT12D) Pair.
So as we know 8 bit communication has 256 possible combinations (2^N bits)
So for now instead of complicating stuff connect ground to pins 1 to 8.
So pins 10 to 13 are the input pins.(Active LOW)
These are usually connected to pushbuttons.
For now we just put pin 10 to a switch.
Pin 11 to Pin 13 to VCC .
Pin 14 must be grounded to transmit the signals
The HT12E Resistor between pin 15 and 16 is important as without it there wont be any data sent
to the RF transmitter.
It must be 20 times the resistor value of HT12D.
We are using a 1.1Mohm Resistor.
Pin 17(Data Pin)
Pin 18(VCC)
RF Module FS1000A (Best RF Module in my opinion)
Here is the schematic diagram
Ok so for the receiver part to receive signals from the transmitter they must be in sync.So to be in sync it is important that Pins 0 to Pin 8 matches the address u have allocated for HT12D.So in this case connect them to ground.
The only output pin thats important is pin 0 since its the only pin we are using on the HT12E side.
Pin 14 is connected with the output of the RF Receiver.Pin 15 to Pin 16 resistor value shd be 51kohm.
Pin 17 is the Valid Transmission pin.So to see if the RF TX is working connect to a 100ohm resistor then to an led then to grd.If its working the LED shd light up.Pin 9 and Pin 18 to gnd and vcc respectively.
This is the schematic diagram
Power Supply
To transmit longer distances more voltage supply is needed so max voltage for the RF TX is 12v .
The RF receiver is not 9v/12v its a typo its 5V.
Antenna
Attach an external antenna
When attaching an external antenna to an RF Module, superior performance can be achieved by selecting an antenna length which will resonate at the wavelength of the carrier frequency. The antenna length should equal to 1/4 of the wavelength of the frequency required in order to achieve resonance and provide the best performance. The length can be calculated using the formula:
C=fλ
Where:
C= Speed of Light
f=Frequency required
λ=Wavelength
The resultant wavelength in metres should be divided by 4 to give the 1/4 wavelength - For example for a 433MHz module, use a 173mm antenna length of wire.
C=fλ
Where:
C= Speed of Light
f=Frequency required
λ=Wavelength
The resultant wavelength in metres should be divided by 4 to give the 1/4 wavelength - For example for a 433MHz module, use a 173mm antenna length of wire.
http://en.wikipedia.org/wiki/Rf_module
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