RF module help

[mackrackit]

Here is a very basic that you can build on.
Transmit snippet

TRAIN	VAR BYTE

TRAIN=$55
SEROUT PORTC.4,T2400,[TRAIN,TRAIN,TRAIN,TRAIN,TRAIN,9,3]

The $55 will "condition" the receiver to a mid point. Then 9 and 3 are sent.

Receive snippet

SERIN PORTC.4,T2400,[9],net

Waits for 9 and puts the next character in var net.

Get this working and then if needed add whatever encoding or chksum or bells or...

Is that coil the antenna? Looks a little long for you frequency. About 6.5 inches for 433mhz. That is wire length. not coil length. But if it works with the hardware encoder...

[dhouston]

Separate the transmitter and receiver physically by 8-10 feet.

[bbarney]

how about getting the modules out of that breadboard and at least on veraboard

[greensasquatch]

Here is a very basic that you can build on.
...
Is that coil the antenna? Looks a little long for you frequency. About 6.5 inches for 433mhz. That is wire length. not coil length. But if it works with the hardware encoder...

I haven't been able to get simple transmit of a high pin state working yet so i'm going to wait for serial data until that works. but thanks for the code anyway.

Yes, that is the antenna as it came prewired from the factory.

Transmitter / Receiver works fine until it's hooked up to the PIC so the antenna must be at least somewhat close. Perhaps it's a 1/2λ antenna?

Separate the transmitter and receiver physically by 8-10 feet.

I usually work with the receiving end on the other side of the room (15 ft away).


I've been reading other threads where people are suggested to try lower clock frequency on their PIC's, buffering the outputs of the PIC and hooking up comparators. I have none of these options available and would like to know if they actually have helped before I order more parts.

[mackrackit]

I haven't been able to get simple transmit of a high pin state working yet so i'm going to wait for serial data until that works. but thanks for the code anyway.

You might be waiting a long time.
The receiver needs "conditioned" or trained. This will basically set the internal capacitor to its mid point. The encoder/decoder chips do this. So if you just send a HIGH, the receiver may already be HIGH and does nothing. The receiver is always receiving something from somewhere, it needs a starting point. dhouston can explain this better or correct me.

[dhouston]

Read this...

• http://davehouston.org/RFTipsTricks.htm

Using the encoder/decoder chips complicate things. Bruce Reynolds posted some code here a few months back showing techniques for working with standalone encoder/decoder chips. The principles will be the same. You'll need to look for the silence that occurs between codes and then listen for the start of the following code.