capture and transmitting of data in PIC16F877

[wowowee]

Hello everybody,
A radio frequency signal can be represented into bits, where am i gonna store this data in an 877?
If I have a sender and a receiver, how will I set the bits and how will I send the RF signal to the receiver? Which one should I use..
Could anybody please help me with this one...

 

[Nigel Goodwin]

I suggest you explain better what you mean?, it makes no sense at all!.

 

[wowowee]

thank you.
Is it possible to send a radio frequency using a PIC16F877? If so, how am I gonna manipulate it? How am I be able to set the bits in that radio frequency so that I would know that radio frequency once received? If radio frequency is successfully sent, how/where am I be able to store that data when captured from another receiver with a different PIC16F877?
thanx again

 

[Nigel Goodwin]

You can't send (or receive) radio signals with a PIC (apart from the RF PIC's, which have it built in), you use licence free radio modules and connect the PIC's to them - check my tutorials for an example.

 

[wowowee]

Thanx for the tutorial.
Considering that a licensed radio module is connected to the PIC, how would I be able to start sending radio frequencies? Will I be able to set the radio frequency from the PIC so that its signal would be unique from the other? How will I implement this?
I'm very sorry if I may annoy you. But I'm really new at this and I need a help from the likes of you..
Thank you very much.

 

[tunedwolf]

The radio frequency of license free radio telemetry modules is pre fixed by the DTI, FCC regulations etc, you cannot change them.

What you do is personalise, or set an address if you like, on your receiver end, so that only your unique address, as sent from the transmitter end, is responded to. Let's say you sent out a 16 bit data burst of binary data from your PIC controller to the data pin on your transmitter module of

10101010 01010101 (from transmitter) (AA 55 hex)

plus the actual data you want to send, say a byte value of 41 hex (65 decimal) or (01000001 binary) or ascii character "A"

then your receiver end will see 10101010 01010101 (AA 55 hex) plus 01000001 (41 hex) (your data)

you set your code in your PIC at the receiver end to only respond when it receives the correct address, your unique binary pattern of
10101010 01010101, unless it gets this first, it just ignores whatever follows...if on the other hand it receives it, then you know that whatever follows is actually your data...

 

[penoy_balut]

rf modules require dc balancing during transmission and reception, you must have some knowledge about Manchester coding and decoding or any method you prefer, you cannot send bits as they are, in my application my data packets consist of 100 bits synch pulse (for noisy environment), header byte, device address byte, data byte, checksum byte.