What will the receiver see if I close the connection on transmitter?

Hello, I am working on a project where I have a basic 433Mhz transmitter and receiver and I am wanting to connect the transmitter data-out directly to the vcc. Will that register as anything the arduino nano could pick up and switch a relay or do I need a pwm device on the transmitter side for the arduino to receive anything? Thanks for the help

That won't work.
A receiver will ignore a constant RF signal.
Only a modulated (data) signal is processed.

Try the RCSwitch receiver and transmitter examples in the IDE.
The transmitter example sends a coded message, so you can select, or turn on/off more than one relay on the receiver.
Leo..

Wawa:
That won't work.
A receiver will ignore a constant RF signal.
Only a modulated (data) signal is processed.

Try the RCSwitch receiver and transmitter examples in the IDE.
The transmitter example sends a coded message, so you can select, or turn on/off more than one relay on the receiver.
Leo..

Further to this, most transmitters themselves need (OOK) modulated data to work, and won't even send a constant burst. There are both maximum and minimum data rates.

Even slow serial comms works fine, up to about 3000-4000bps.

Hi,

I am wanting to connect the transmitter data-out directly to the vcc.

Whaaa...
The Tx has data input and RF output (aerial).
The Rx has RF input (aerial) and data output.

Can you please explain what you want to do.

Thanks.... Tom.... :slight_smile:

TomGeorge:
Hi,Whaaa...
The Tx has data input and RF output (aerial).
The Rx has RF input (aerial) and data output.

I am wanting to connect the transmitter data-out

I took him to mean the transmitter data input. Nothing else made sense, as you rightly point out.
He's confusing 'data out' (to the transmitter) with 'data in' (at the transmitter).

Won't work how he wants anyway. :frowning:

433mhz OOK/ASK receivers use AGC (automatic gain control); you get the same thing with a constant on signal as a constant off "signal", that is, the output transitions randomly because it adjusts the gain and threshold such that it gets a ~50% duty cycle.

There's also the VirtualWire library, or the more ambitious users might write their own protocol (that's what I did)

What you can't do is just pipe the tx pin of a serial port to the input of the transmitter, and the rx pin of a serial port to the output of the receiver, and expect to get anything coherant out. It may work sometimes, but it will not work reliably enough to do anything with.

DrAzzy:
What you can't do is just pipe the tx pin of a serial port to the input of the transmitter, and the rx pin of a serial port to the output of the receiver, and expect to get anything coherant out. It may work sometimes, but it will not work reliably enough to do anything with.

I've used slow serial in the past with those TX/RX pairs. I just used a PIC chip that sat and waited in a loop for a given 'qualifier', then reacted to the following data. 100% blocking. I guess it could be a problem using interrupt-based code though. I hadn't given that a thought.

OldSteve:
I took him to mean the transmitter data input. Nothing else made sense, as you rightly point out.
He's confusing 'data out' (to the transmitter) with 'data in' (at the transmitter).

Won't work how he wants anyway. :frowning:

Sorry, I worded that wrong, you figured it out...