RF newbie..electronics newbie

[jbchrist]

Hi,

I just bought the RF Link - 4800bps - 315MHz from sparkfun (https://www.sparkfun.com/commerce/product_info.php?products_id=7816)
I am trying to understand how to use it.

I read as much as I can, but am still a little bit confused. I just don't understand all the datasheets as good as I want to.

On the transmitter can I put an analog voltage on the data pin? If so, what can I expect on the receiver data pins. If not, what do I need to do to my analog signal to transmit it?

Thanks

 

[G8RPI]

Hi,
You cannot put an analogue voltage directly onto the pin of this module. The module is for digital data transmission, for example connecting two computer serial ports together.
Ideally you need a microprocessor with a analogue to digital converter to turn your voltage into serial data at the transmitter. At the reciver you can directly connect to a PC serial port or use another micro and a digital to analogue converter to get your signal back to a voltage.
It may be possible to convert you voltage to a variable frequency or Pulse Width Modulation (PWM) data stream an transmit that but it depends on the TX and RX you are using. I've not looked at the data sheets for the ones you have, but simpler ones work beast for this.

HTH Robert.

 

[Nigel Goodwin]

You need to be VERY aware that serial (RS232) requires DC coupling, and wireless links are AC coupled, it's normal to use some type of NRZ coding, such as Manchester coding.

 

[jbchrist]

You need to be VERY aware that serial (RS232) requires DC coupling, and wireless links are AC coupled, it's normal to use some type of NRZ coding, such as Manchester coding.

I don't understand what you are saying. I'm kind of new to this.

 

[Nigel Goodwin]

I don't understand what you are saying. I'm kind of new to this.

Read my wireless PIC tutorial, which explains the problems - or, probably better still?, buy more expensive radio modules that have the required coding built-in.