Simple RF Transmit and Receive

[koossa]

Dave

I have updated my Schematics and used your source code.
I have made a couple of mods on the code, but it does not seem to work, don't know if I have missed something.

I am using MS Terminal to view the incomming data on the PC. The data did only came through once and it was a couple of junk characters.

Thank you very much for all your help!!

[dhouston]

In your schematic, change both 22K resistors to 1K. These merely limit the current to what is safe. 5V / 1000R = 0.005A (5mA). The 22K is needed only when the voltage is higher as with an input from a PC using RS232 voltage levels. Here, all the voltages are 5V max.

In the code, comment out IF (space<40) OR (space>175) THEN init.

In the code, modify DEBUG (RF[i] REV 8) to send either hex or decimal representations of the bytes. I'll let you consult the manual for details. My code sends the Ascii byte values which may not all be printable characters, especially in MS Terminal.

HEX 50 AF 42 DB
DEC 80, 175, 66, 189
ASC P, », B, ╜

The protocol is explained at http://davehouston.net/rf.htm

[koossa]

Dave

I have made all your suggested changes.
I don't receive anything on the PC side, but for a test I have moved the RS232 to the transmitter. (Disconnected the TXD Pin and put the RS232 in its place)
Then I receive the following characters.

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ðððððððððððððððððððððððððððððððððððððððððððððððððð ðð

[dhouston]

I don't have your hardware so I cannot set this up here and test it. I don't have the time for that anyway. I can only tell you I've used the code many, many times with 12F629, 12F675 and 12F673 and ASK RF modules.

You will only see garbage when you connect the transmitter TXD pin to RS232 as it is sending NEC protocol not RS232 protocol.

However, if you go back to your original approach, using SerOut & SerIn, you can send RS232 from the transmitter which might serve as a sanity check.

[lil_mark]

Hi All, Hi Dave
I wish you all a happy new year.

I'd like to thanks Dave for his code and... compliments for your website. It's full of precious infos.

I'm using your code on a pair of 18F4550@4Mhz and a couple of LAIPAC RLP/TLP 434 with success.

I'm asking for your(Dave's) help because I'd like to use the receiver code using a PIC clock speed @ 20Mhz.

I'v tried dividing the timings by 5 but without success.

Can you kindly help me posting a code sample working @ 20Mhz.

Sorry for this apparently stupid question, but i'm trying and trying again...

Thank you,
Regards,
Mark.

[dhouston]

I'm glad you find the code and web site helpful. That's their purpose.

You're going in the wrong direction. Read the PulsIn/PulsOut sections in the manual. It uses 4MHz and 20MHz as examples and indicates you need to multiply instead of dividing.

[dhouston]

lil_mark,

If you are also using 20MHz for the transmitter circuit, you will need to add DEFINE OSC 20 to that code so that PauseUS can adjust its timing.

[lil_mark]

Hi All, Hi Dave
I wish you all a happy new year again.

Sorry for my previous post.

I forgot to change the DEFINE PULSIN_MAX command.

Thanks again to everybody.

Regards,
Mark.