RF Transmitters and Receivers?

[jeff77789]

I've been trying to use this pair of RF transmitter/receiver:

https://www.sparkfun.com/products/10534
https://www.sparkfun.com/products/10532


does anybody have any experience with what type of signal it actually sends/receives?

you see that in the datasheet for the receiver you have a digital output and a linear output as well.

I sent a pwm type output through this and it looks like it kind of successfully transfers but the signal is very noisy, disrupting the pwm signal. i dont think an analog voltage signal would transfer

thanks

 

[davenn]

they use amplitude shift keying

see here


cheers
Dave

 

[jeff77789]

okay so i finally figured out to find a digital signal to send through these. there is another problem that comes up:

1. the signal being sent to the transmitter is 9600 baud which is 2x the 4800baud for the tx/rx (which i do not know if it affects the signal any)

2. when i view the signal, it is very noisy and it looks like it is just random numbers. the thing is, if i turn off the Tx, the values stay in their random state and it looks like there is no uniformity

 

[brevor]

1. Sorry, you can't send 9600 baud data through a TX/RX that only supports up to 4800 baud.

2. Im not sure what you mean by this. Please explain a bit more.

 

[(*steve*)]

Yeah, I'd certainly be trying to get it to work at 4800 baud before pushing it beyond its specs.

It *may* work at 9600 baud, but it may do so only with a very high signal, low noise, etc. Or it might not work at all.

 

[jeff77789]

Now I am at the point where i can send a digital signal at 4800 baud through these sensors.

The thing is, If it send "123" on the other side, i rarely ever get the "495051" sequence (refer to ASCII table)

the accuracy rate is less than 10% and I have no Idea why the signal is so "noisy"

is there any way i can improve on this?