RF Communication between two pics.

[rk396]

Sorry if this a redundant question, but i'm having difficulty with getting RF communication to work.

Here's what I've done so far. I picked up a matched transmitter receiver combo. Wired them up per the data sheets. On the two pics (18f1320) I've enabled the hardware usart. My data packet structure is to send (3) 255's then the data. When i wire the two chips up directly this works fine, the data comes thru no problem, when i run this sequence to the transmitter... i get nothing.

I've read thru several tutorials on this subject, and i seem to get different info from all of them. Some say i need to transmit 20 1's, some say i need to invert the RS232, and some say it should work just as what i've done. soooo....

my question is what's the real story with these. Oh I'm using C18 as my language.

thanks in advance to anyone that can shed some light on this subject.

 

[Nigel Goodwin]

Sorry if this a redundant question, but i'm having difficulty with getting RF communication to work.

Here's what I've done so far. I picked up a matched transmitter receiver combo. Wired them up per the data sheets. On the two pics (18f1320) I've enabled the hardware usart. My data packet structure is to send (3) 255's then the data. When i wire the two chips up directly this works fine, the data comes thru no problem, when i run this sequence to the transmitter... i get nothing.

I've read thru several tutorials on this subject, and i seem to get different info from all of them. Some say i need to transmit 20 1's, some say i need to invert the RS232, and some say it should work just as what i've done. soooo....

my question is what's the real story with these. Oh I'm using C18 as my language.

thanks in advance to anyone that can shed some light on this subject.

As in all the other similar threads - you can't generally send plain RS232, you need to encode it, Manchester is the usual method.

Check my tutorials for more details.

 

[3v0]

Do you have a link to your TX RX datasheet ?

 

[rk396]

Nigel, thanks for the quick reply, i will take a look,

Here is a link to the RF TX and RX that I'm using.

https://www.electro-tech-online.com/custompdfs/2011/12/QAM-RX2.pdf

https://www.electro-tech-online.com/custompdfs/2011/12/QAM-TX1.pdf

I know the two will talk, as i've been able to get them to sync, just not consistantly.

 

[Nigel Goodwin]

Nigel, thanks for the quick reply, i will take a look,

Here is a link to the RF TX and RX that I'm using.

https://www.electro-tech-online.com/custompdfs/2011/12/QAM-RX2-1.pdf

https://www.electro-tech-online.com/custompdfs/2011/12/QAM-TX1-1.pdf

I know the two will talk, as i've been able to get them to sync, just not consistantly.

Notice the datasheet shows an RF Solutions RF600D, this is a Manchester encoder/decoder - but you can do it directly in a PIC as per my tutorials (and I seem to recall that the RF600D is actually a pre-programmed PIC)