Control NEXA 230V RF Switch

A PIC program for control NEXA 230V Switch with a PIC and the parallax RF transmitter
Bruce from www.rentron.com helpt me write this code, actually he wrote the hole code to me :)

http://www.nexa.se/res/produktbilder_stora/143021.jpg
http://www.parallax.com/Portals/0/Im...79/27980-M.jpg
Pictures are from
www.nexa.se and www.parallax.com

Code:

<html> <head></head> <body><pre><code>'**************************************************************** '* Name : NEXA RemoteControl * '* Notice : Copyright (c) 2008 [select VIEW...EDITOR OPTIONS] * '* : All Rights Reserved * '* Date : 2008-12-30 * '* Version : 1.0 * '* Notes : PIC 16F872 @ 20 Mhz * '* : * '**************************************************************** DEFINE OSC 20 T CON 350 ' T = 350uS T3 CON 1050 ' 3T T32 CON 11200 ' 32T (Stop/Synch) ' Note we're using 1 VS X as shown in text A1_ON CON %111000000000 ' 12-bit code for House/Unit A1 ON A1_OFF CON %011000000000 ' 12-bit code for House/Unit A1 OFF ' ||||||||||||____ 4-bit House code ' ||||||||________ 4-bit Unit code ' ||||____________ 3-bit Unknown code ' |_______________ 1-bit Activation code 1=ON 0=OFF ' ' House code Unit Code ' ------------------------ ' | 0000 - A | 0000 - 1 | ' | X000 - B | X000 - 2 | ' | 0X00 - C | 0X00 - 3 | ' | XX00 - D | XX00 - 4 | ' | 00X0 - E | 00X0 - 5 | ' | X0X0 - F | X0X0 - 6 | ' | 0XX0 - G | 0XX0 - 7 | ' | XXX0 - H | XXX0 - 8 | ' | 000X - I | 000X - 9 | ' | X00X - J | X00X - 10 | ' | 0X0X - K | 0X0X - 11 | ' | XX0X - L | XX0X - 12 | ' | 00XX - M | 00XX - 13 | ' | X0XX - N | X0XX - 14 | ' | 0XXX - O | 0XXX - 15 | ' | XXXX - P | XXXX - 16 | ' ------------------------ D_PACKET VAR WORD ' Holds 12-bit data packet to send INDEX VAR BYTE ' Data packet bit index pointer LOOPS VAR BYTE ' Loop counter TX VAR PORTB.0 ' Connects to RF transmitter data in LOW TX ' TX output idles low for RF carrier OFF Main: D_PACKET = A1_ON GOSUB Send PAUSE 5000 D_PACKET = A1_OFF GOSUB Send PAUSE 5000 GOTO Main Send: FOR LOOPS = 1 TO 4 ' send each packet 4 times FOR INDEX = 0 TO 11 ' sends 12 bits per pass LSB 1st HIGH TX ' The 1st half of a 0 or X bit period is the PAUSEUS T ' same so no need to repeat this sequence inside LOW TX ' the IF block PAUSEUS T3 IF D_PACKET.0[INDEX]=1 THEN HIGH TX ' send a 1 bit (1=X here) PAUSEUS T3 LOW TX PAUSEUS T ELSE HIGH TX ' send a 0 bit PAUSEUS T LOW TX PAUSEUS T3 ENDIF NEXT INDEX ' loop until all 12-bits sent ' Start of Stop/Synch period after each 12-bit packet HIGH TX PAUSEUS T LOW TX PAUSEUS T32 ' End of Stop/Synch period NEXT LOOPS ' send 4 packets per pass RETURN END </code></pre></body> </html>

decode ?

Hi all

Could somebody please help the code on the receiver side , in other words to decode this ?
the reaosn I am sasking is because I have the very same system at home and would like to add my little PIC project as a receiver to it.

Here's what I thought would work so far ....

Code:

'**************************************************************** DEFINE OSC 20 T CON 350 ' T = 350uS T3 CON 1050 ' 3T T32 CON 11200 ' 32T (Stop/Synch) D_PACKET VAR WORD ' Holds 12-bit data packet to send INDEX VAR BYTE ' Data packet bit index pointer LOOPS VAR BYTE ' Loop counter RX VAR word ' Connects to TX receiver data in RXPORT VAR portb.0 RFCOUNT VAR byte[2] 'possibly be needing this BITCOUNT var byte ' count number of bits received MARKER var byte 'check pauses or spaces of incoming pulse receive: LOW RX ' RX output idles low for RF carrier OFF DEFINE PULSIN_MAX 11200 '>11200 RETURNS 0 PulsIn RXPORT,1,RX 'receive pulse on portb.0 and hold in RX If (RX<11200) Then receive 'pulse is too short or > pulsin max try again While RXPORT=0:Wend 'wait pulse

And that's where I'm stuck :-(
What is the next thing to look for ? T or T3 and how would the code look ?
Do I use a WHILE loop ?
Should I be adding a REPEAT UNTIL ?
I imagine a counter condition needed as well until we reach 12 bits
Should I even be using pulsin or not ?

Any help would be greatly appreciated.

Kind regards

Dennis

Quote:

Originally Posted by Dennis

Code:

DEFINE PULSIN_MAX 11200 '>11200 RETURNS 0

You need to change this. I suggest you make it 120% of the greatest expected pulse. Battery operated transmitters can vary ±10-15%.

Also, there is no 1:1 correspondence between uS and the units used by PulsIn. You need to study and understand the manual. At 20MHz, PulsIn units are 2uS.

pulsin max

Hi again Dave

Hope all is well with you :-)

Thanks for the reply.

As always it has sent me hurtling off to get more info about pulsin and pulsout

So regarding your reply ...

Assuming the reciver side is also @ 20 MHz and T =350uS and 32T as per the above code is 11200 would that mean a figure of 13440 would be acceptable

Code:

DEFINE PULSIN_MAX 13440 >13440 returns a 0

or have I done the wrong by taking 120% of 11200
Should it be less ?
The reason I am asking is what happens if the pulse is less than 13440 , let's say it is the actual max without variance and is spot on as 11200 that arrives...do we just discard it ?
If I take max as 11200 and then take off 15% that leaves me with a figure of
9520.
This seems to be the one I should use because if the pulse is anything less than this then we should discard it right ?
Now i have a MIN and a MAX for the received initial pulse and something to test against right.
So...
IF pulsein < 9520 or > 13440 then discard it

Is that correct ?

Kind regards
Dennis

Do i have it correct so far ?