I am using a circuitry to send data through wireless.. using RF of frequency 433Mhz
my circuit is as follows
the problem here is that this works only when i connect both transmitting and receiving circuit to a common ground.
but in wireless communication i cant use a common ground to both transmitter and receiver as they are apart from each other.
could someone tell me a better solution

basically i am using a single wire instead of RF transmitter and receiver just to check that my encoding and decoding circuit working properly or not

 

But when you actually use RF, rather than wires, the planet earth acts as a common ground. If it works over a wire with a common ground, try it with the RF modules.

 

If you are using the same Vcc, then of course they need the same ground.

 

These modules with different power supplies without any problem.
Make sure that you are using good power supplies.
Try the following link, it might help you
Wireless Transmitter and Receiver using ASK RF Module

 

If you are using the same Vcc, then of course they need the same ground.

Iam using seprate vcc for both ends

 

But when you actually use RF, rather than wires, the planet earth acts as a common ground. If it works over a wire with a common ground, try it with the RF modules.

I did use rf module and it works.. but here a new problem..
Basicly i am using 433Mhz rf module.. so the range should be about 80-100m
But in my case i acheive only less then 2m range.. beyond it..its not working..
Dont knw where is the prblm.. plz help sm1

 

Please provide details of the RF modules. Have you connected antennas to both of them? Are they in boxes or enclosures?

 

Please provide details of the RF modules. Have you connected antennas to both of them? Are they in boxes or enclosures?

yes i have connected a wire antenna of about 5cm

 

Hello,

I think that the antenna is to short.
Wave lenght for 433 MHz is about 300/433 = 0.693 meter.
A quarter wave will be 0.693 / 4 = 0.173 meter => ca. 17 centimeter.

Bertus

 

iam somewhat confused here.. here in my circuit diagram it uses 750k ohm between the pin n0. 3 and 4 of encoder for oscillator and 27 k ohm at the decoder end..
but in some tutorials i have seen 1M ohm at the encoder and 33K ohm at the decoder..
well i have seen what iam doing in many tutorial too..
can some one explain this? does iam doing somthing wrong?