free license band RF module

[sysysy]

Hello,

I am doing a project and trying hard to understand the operation theory of this type of RF module(315Mhz and 433Mhz).

From the datasheet, it say that the RF transmitter just will transmit out the data whenever there 'see' the data at the data pin....Hmmm, in my project, of course i put the data that i want to that pin through the microcontroller.

But the problem raise up in my mind, how actually this rf module work?
Are the transmitter juz simply modulate the data to 315hMhz with the data and send out and the receiver do the demodulation for the data?

For a asynchronous communication, both side of my microcontroller must need to have a same baud rate. let say i set both in 4.8k baud rate... so, how this baud rate affect my rf module? becoz from the module, i see the receiver have its own crystal mean clock...but transmitter does not have... i suspect they also need have their own baud rate in communication instead of we set it in microcontroller... how to relate this?

i really feeling blur to this...juz hope anyone can explain and lead me to correct track. Thanks alot.

 

[Nigel Goodwin]

Read my PIC tutorial about wireless modules.

 

[sysysy]

Hi Nigel,

i did read ur tutorial before. But the things i curious is how the rf module hardware work? how it transmit out the data...
is it it doing ntg but just act like a wireless transmission tool only? and all the things about the UART is actually done by MCU only.

 

[Nigel Goodwin]

Hi Nigel,

i did read ur tutorial before. But the things i curious is how the rf module hardware work? how it transmit out the data...
is it it doing ntg but just act like a wireless transmission tool only? and all the things about the UART is actually done by MCU only.

The wireless side is totally dumb, essentially it's either turned ON and OFF, or shifted between two frequencies, to produce two different signals.

Also don't even think UART, it's not particularly suitable for RF links.