How do I detect a polarity change on an input?

[ardhuru]

Forgot to add, there are readymade basic snippets on the web that directly let a stamp drive an X10 firecracker as well; would achieve the same objective you seek.

Regards,

Anand

[jessey]

Thanks Anand,

I've been away visiting with a friend without a computer (hard to believe now a days). Now that's something that I'd definitely be interested in investigating. I surely would appericate receiving the URL's if you could please send them to me.

Thanks Again
jessey

[ardhuru]

Hi Jessey,

To begin with, here's Dave excellent page on the X10 RF protocol http://www.arkis.net/rf_protocol.htm.

This would give you a pretty good starting point.

The other approach would be to use a CM17A (Firecracker) module; this would eliminate the need for a separate RF transmitter. Theres loads of basic software available to drive it; one such page is at http://www.awce.com/firecracker.htm

Hope this helps!

Regards,

Anand

[jessey]

Hello Anand,

Thanks for the links, I've had some time now to ponder over the firecracker stamp code and have some questions if anyone can help me. I've never had any experience using the Stamp so it'll definitely be a learning experience for me. I ordered a firecracker and expect to have it in a week or so. It sure would be nice to be able to get rid of all the reed relays and transistors that I'm using now on my modified X10 remote control.

I've checked the archives for any conversion tips for converting Stamp code to PBP and I did manage to find someone quoting that there are no NIB's in PBP so I changed all the NIB's to BYTE variables as the thread recommended.

I also found that the stamp code didn't declare the port pins for the push buttons so I declared them as well. Another thing I did was to change the rts & dtr from CON statements to declaring them as port variables to enable setting them high and low in the PBP code for the transmitter (firecracker) and I'm also assuming that all I have to do for the ground of the transmitter is to tie it to the VSS of my 16F877.

What I don't understand is that when I try to compile the code I get 3 errors:
"error.macro and?bbl not found in macro file", is this some sort of an include file that I'm missing or something that I have to add or declare somewhere?

Also I get two bad expressions, one for "READ housetbl+house,byt" and the other for "READ unittbl+(unit//8),tmp", is there a conversion for these two that will work for PBP? Could it be that the Data statement is wrong for PBP and possibly it needs an @ sign in there?

Any help in understanding this code will be greatly appreciated.

Thanks
jessey

'************************************************************
'*  Name    : FIRECRACKER.BAS                               *
'*  Author  : Jessey Montgomery                             *
'*  Date    : Feb. 2nd, 2008                                *
'*  Version : PBP ver 2.45, MicroCode Studio 2.1.0.7        *
'*          : MPASM v03.60, EPIC Version 2.46 beta          *
'*          : 16F877                                        *
'*  Notes   :                                               *
'*          :                                               *
'************************************************************

'                          --------------                     
'                          |   16F877   |                     
'         MCLR/Vpp ------> |1         40| <-----> RB7/PGD     
'          RA0/AN0 <-----> |2         39| <-----> RB6/PGC     
'          RA1/AN1 <-----> |3         38| <-----> RB5         
'    RA2/AN2/Vref- <-----> |4         37| <-----> RB4         
'    RA3/AN3/Vref+ <-----> |5         36| <-----> RB3/PGM     
'        RA4/TOCK1 <-----> |6         35| <-----> RB2         
'       RA5/AN4/SS <-----> |7         34| <-----> RB1         
'       RE0/RD/AN5 <-----> |8         33| <-----> RB0/INT0    
'       RE1/WR/AN6 <-----> |9         32| <-----  Vdd +       
'       RE2/CS/AN7 <-----> |10        31| <-----  Vss -       
'            + Vdd  -----> |11        30| <-----> RD7/PSP7    
'            _ VSS  -----> |12        29| <-----> RD6/PSP6    
'        OSC/CLKIN  -----> |13        28| <-----> RD5/PSP5    
'      OSC2/CLKOUT <------ |14        27| <-----> RD4/PSP4    
'  RC0/T1OSO/TICK1 <-----> |15        26| <-----> RC7/RX/DT   
'   RC1/T1OSI/CCP2 <-----> |16        25| <-----> RC6/TX/CK   
'         RC2/CPP1 <-----> |17        24| <-----> RC5/SDO     
'      RC3/SCK/SCL <-----> |18        23| <-----> RC4/SD1/SDA 
'         RD0/PSP0 <-----> |19        22| <-----> RD3/PSP3    
'         RD1/PSP1 <-----> |20        21| <-----> RD2/PSP2    
'                          --------------              

'-----------------------------------------'
'-- Clear All The Variables And Each Port '
'-- Before Setting The TRIS Registers     '
'-----------------------------------------'
 
  Clear     ' Set all ram registers to zero
  PORTA = 0
  PORTB = 0                           
  PORTC = 0   
  PORTD = 0
  PORTE = 0
 
'-----------VSS VDD MCLR Ect. Pins -----------'
 
' MCLR         (Pin 1)
' VDD          (Pin 11)
' VSS          (Pin 12)
' OSC/CLKIN    (Pin 13)
' OSC2/CLKOUT  (Pin 14)
' VSS          (Pin 31)
' Vdd          (Pin 32)
 
 '-----------SET THE TRIS PINS BEING USED-----------'         
 
 '-------------------- PORTA PINS --------------------'
             
  TRISA.0 = 1 '(pin 2) NOT USED  
  TRISA.1 = 1 '(pin 3) NOT USED 
  TRISA.2 = 1 '(pin 4) NOT USED 
  TRISA.3 = 1 '(pin 5) NOT USED 
  TRISA.4 = 1 '(pin 6) NOT USED  
  TRISA.5 = 1 '(pin 7) NOT USED  
 
 '-------------------- PORTB PINS --------------------'
 
  TRISB.0 = 1 '(pin 33) NOT USED   
  TRISB.1 = 1 '(pin 34) NOT USED   
  TRISB.2 = 1 '(pin 35) NOT USED   
  TRISB.3 = 1 '(pin 36) NOT USED  
  TRISB.4 = 1 '(pin 37) NOT USED 
  TRISB.5 = 1 '(pin 38) NOT USED    
  TRISB.6 = 1 '(pin 39) NOT USED  
  TRISB.7 = 1 '(pin 40) NOT USED 
 
 '-------------------- PORTC PINS --------------------'

  TRISC.0 = 1 '(pin 15) NOT USED
  TRISC.1 = 1 '(pin 16) NOT USED
  TRISC.2 = 1 '(pin 17) NOT USED 
  TRISC.3 = 1 '(pin 18) NOT USED  
  TRISC.4 = 1 '(pin 23) .......Pushbutton or input from LabXT 
  TRISC.5 = 1 '(pin 24) .......Pushbutton or input from LabXT  
  TRISC.6 = 1 '(pin 25) .......Pushbutton or input from LabXT 
  TRISC.7 = 1 '(pin 26) .......Pushbutton or input from LabXT     
 
 '-------------------- PORTD PINS --------------------'
 
  TRISD.0 = 0 '(pin 19) ........used to power the firecracker   
  TRISD.1 = 0 '(pin 20) ........used to power the firecracker    
  TRISD.2 = 1 '(pin 21) NOT USED    
  TRISD.3 = 1 '(pin 22) NOT USED  
  TRISD.4 = 1 '(pin 27) NOT USED   
  TRISD.5 = 1 '(pin 28) NOT USED   
  TRISD.6 = 1 '(pin 29) NOT USED   
  TRISD.7 = 1 '(pin 30) NOT USED  
 
 '-------------------- PORTE PINS --------------------'
 
  TRISE.0 = 1 '(pin 8)  NOT USED   
  TRISE.1 = 1 '(pin 9)  NOT USED   
  TRISE.2 = 1 '(pin 10) NOT USED


DEFINE OSC 4         ' 4MHz crystal
 
@ __CONFIG _HS_OSC &_BODEN_OFF &_PWRTE_ON &_WDT_ON &_CP_OFF 
&_LVP_OFF
' turn off the Crossing page boundary warnings
@ errorlevel -306 

 ADCON1 = 7   ' Set PORTA and PORTE to digital

' This is a link to the orginal code below, 
' http://www.awce.com/firecracker.htm

' Define Variables Here
' ---------------------
' byte to send
 byt var byte
 tmp var byte
 i var BYTE 'was a nib
 x var BYTE 'was a nib
 state var bit(4)
 house var byte '0=A 1=B...
 unit var BYTE  ' 0-15  (must be 0 for bright/dim) 'was a nib
 cmd var BYTE  ' 0=off 1=on 2=bright 3=dim 'was a nib

'these push buttons weren't declared 
 in11 VAR PORTC.4 ' (pin 23)..Pushbutton or input from LabXT
 in10 VAR PORTC.5 ' (pin 24)..Pushbutton or input from LabXT
 in9  VAR PORTC.6 ' (pin 25)..Pushbutton or input from LabXT
 in8  VAR PORTC.7 ' (pin 26)..Pushbutton or input from LabXT


' Firecracker Interface (Al Williams)
' http://www.al-williams.com/awce
' Wire Ground (DB9 pin 5)
' DTR (DB9 pin 4)
' RTS (DB9 pin 7)
'rts con 1
'dtr con 0
rts VAR PORTD.0 ' pin 19 
dtr VAR PORTD.1 ' pin 20 

' The Firecracker header (2 bytes)
h1 con $D5
h2 con $AA

' the Firecracker footer (1 byte)
foot con $AD

gosub resetfirecracker

' Sample program
main:
' all off
  for x=0 to 3
    house=0
    unit=x
    cmd=0
    gosub sendcmd
    pause 20
    state(x)=0
  next

mainloop:
  if in11=0 then c0  ' look for buttons on p8-11
  if in10=0 then c1
  if in9=0 then c2
  if in8=0 then c3
  goto mainloop

c0:
  x=0
  goto ccmd
c1:
  x=1
  goto ccmd
c2:
  x=2
  goto ccmd
c3:
  x=3
ccmd:
  unit=x
  cmd=state(x)+1
  if cmd=1 then gocmd
  cmd=0
gocmd:
   gosub sendcmd
   pause 250
   state(x)=cmd
   goto mainloop

' End of example program

' Send command
sendcmd:
  byt=h1
  gosub sendbyte
  byt=h2
  gosub sendbyte
  read housetbl+house,byt
  if unit<9 then lowunit
  byt=byt+4
lowunit:
  gosub sendbyte
  byt=$20
  if cmd=0 then addunit
  byt=0
  if cmd=1 then addunit
  byt=$88
  if cmd=2 then nounit
  byt=$98
  if cmd=3 then nounit
' huh???

addunit:
  read unittbl+(unit//8),tmp
  byt=byt+tmp
nounit:
  gosub sendbyte
  byt=foot
  gosub sendbyte
return

' Send 1 raw byte
sendbyte:
  debug hex byt," "
  for i=0 to 7
   if byt & $80 = $80 then xmit1
   gosub send0
nextbit:
   pause 1
   byt=byt*2
   next
   return


' Send a 1
xmit1:
  gosub send1
  goto nextbit


' Send bits (0 or 1)
send0:
  low rts
  pause 1
  high rts
  return

send1:
  low dtr
  pause 1
  high dtr
  return


' Always reset firecracker first
resetfirecracker:
low rts
low dtr
pause 50  ' reset
high rts
high dtr
pause 50
return

' Data for house and unit codes
' should there be an @ somewhere below for pbp?
housetbl data $60,$70,$40,$50,$80,$90,$A0,$B0,$E0,$F0,$C0,$D0
      data $00,$10,$20,$30
unittbl data 0,$10,$8,$18,$40,$50,$48,$58

[Darrel Taylor]

Hi Jessey,

Can't comment on the FireCracker thingy, but I beleive the and?bbl problem is in the
    if byt & $80 = $80 then xmit1
Statement.

Putting parenthesis around the bitwise AND should fix it.
    if (byt & $80) = $80 then xmit1
<br>

[Darrel Taylor]

Oh, and putting the EEPROM Data at the top of the program instead of the bottom, should fix the other error.

hth,

[jessey]

Thanks Darrel,

That worked out great, now the boring part is that I have to wait until my firecracker makes it here to see how it works as is before I start modifying the program to interface to my LabXT telephone board.

Thanks Again
jessey