Hello, i purchased a cheap 433mhz transmitter and receiver from eBay and i will have a schematic below of my setup. Basically i want to press a push button that connects data pin to 5v on the transmitter and also lights up a LED in series.
On the receiver side i have the 2 middle data pins pulled together and i have a small ceramic capacitor hooked in parallel.
I understand that the receiver picks up different signal from around my house (noise), which makes the led on the date receiving side blink rapidly, but when i press the button on the transmitter the led on the transmitting and receiving sides goes solid, so i know that it is semi-working.
I want to know how to eliminate noise without the use of a micro controller.
My ultimate goal is to be able to send a clean 5v signal to the receiver that will eventually power the signal pin of a relay to be able to control different devices.
I want to know how to eliminate noise without the use of a micro controller.
Not possible. The noise is inherent to radio communications, and is amplified in these cheap receivers by using automatic gain control. Only by intelligently modulating the signal can you get around it, to a certain extent.
That is not possible with the device that you got.
Those automatically adjust gain and sensitivity so that they output an approximately 50% duty cycle signal. If there is no transmitter transmitting, they output noise. If the transmitter is on 100% of the time, the output noise. You need intelligence at both ends - on the transmitter side, a signal with approx 50% duty cycle needs to be generated, and sent several times. Maybe with a training burst (50% duty cycle, before the actual data, to help the automatic gain correction adjust itself). On the receiving side, it needs to be able to tell the difference between noise and the signal you sent, and pick that out of the sea of noise.
There are ebay modules that integrate single-purpose IC's that have an encoder and decoder IC included, which generates output that could control an LED without an Arduino. But the ones you have don't have that. jremmington posted a link to such a device. They are also available on ebay (for somewhat less if you're willing to endure the china shipping delay)
You need a receiver with a squelch circuit. This is normally found on FM receivers but could be on any modulation method.
A squelch circuit looks at the RF signal level received and gates to output ( turns it off ) unless it is above a certain threshold, often set by a pot.
