SparkFun Forums

[JJRD]

Hello friends.

I recently purchased an RF Link Receiver - 4800bps (434MHz) from Sparkfun and plugged it along with a 434mhz transmitter. The transmitter works fine I think, since I definitely got something at the receiver when I sent a signal.
The problem is I get random numbers constantly coming down on the serial monitor.

I'm using Arduino Uno, sending to another Uno. When plugged directly via wire, I send/receive no problem.
But when I plug in the Rx module I get garbage constantly, even when the Tx is out.

I wonder why it's doing that?
Example:

0
248
120
240
240
192
120
254
0
30
0
31
248
0
128
0
240
248
252

[lyndon]

They are bare receivers and transmitters. That's the only function they provide. Nowhere does it say they will transfer serial data.

If you want to send serial/digital data, you will have to encode it somehow. I use them to send PWM for controlling servos and they do that quite well.

[jremington]

You need to use something like the Arduino VirtualWire or RadioHead libraries to send data reliably.

[JJRD]

Thank you, I know there's a lot of noise on the line. I don't have to transmit a lot of data, I reduced the noise on the line by adding a cap. It doesn't get rid of all of it, but I get a lot more "0"s than I did before. It's clean enough for what I do.
Perhaps if need better yet, I can transmit the data in the form of PWM...?

[JJRD]

Maybe I can put the scope to the signal and find out if the threshold of the noise is lower than the signal, then a filter would get rid of all of it.... looks like it.

248
0
0
0
0
0
0
0
0
0
255
0
0
0
0
0
0
0
0
0
255
0
0
249
0
0
0
0
0
252
0
0
0
0
0
0
248
0
248
0