Help with serin, serout, Manchester encoding

[skimask]

This is a part of the 2 way paging system that I am doing for a project. Basically what I am trying to do is take 4 bits from the transmitter that I get at the receiver end and do some operations on it. I am assuming that the first two bits are the address and the last two bits are the mode. There are two modes tracking and finding. In each case, I am first checking the last two bits to see which mode it is. After I do that, I am checking if the first two bits of address matches. If the address matches, it will change the third bit (kind of like an acknowledgement) and output the result somewhere. If it does not match it will not change the code and output it back. In the find mode, it does the same thing except it will make a pin high in order to set off an alert like a LED. Is this making any sense?

Ok, that makes a bit more sense....
A bit (pun intended) simpler, maybe????......
Take a sent byte...invert it and send it back as some sort of acknowledge.
For instance: (using 4 bits, $5, $A, $0, $F, are already taken, so can't use those)
Send $1, return $E, acknowledged
Send $2, return $D, and so on...
Anything else returned would be 'not' acknowledged...
Leaves you with $1,2,3,4,6,7 for send codes ($E,D,C,B,9,8 for returned codes).... if 6 codes is enough for you...
That way you could set the 'address' for each pager/receiver with 3 DIP switches (with 2 unused combo's)...

[oneohthree]

Would it matter if I used t2400 or n2400 in my code for serin/serout? I used n2400 in my code and everything is encoding and decoding correctly. I know this because the number at the receiver checks when I write the result into EEPROM and convert the hexadecimal to binary. Also, it seems like the receiver code does not go to the if statements at the end. For example, if I receive 1100 it serout something to pin 1. When I put a LED at pin 1 I don't see anything. Is there anyway I can fix it? Would I have to change my decoded message from hexadecimal to binary in order to allow me to manipulate the bits?

'Transmitter Code
'Transmitter Code
Include "Modedefs.bas"
main:
v var byte : counter var byte : encoded var byte : v = %1100
'Manchester encoding
For counter = 0 to 3
If v.0[counter]=0 Then
encoded.0[counter*2]=0 : encoded.0[counter*2+1]=1 'If it is a zero make the first bit 0 and second bit 1
Else
encoded.0[counter*2]=1 : encoded.0[counter*2+1]=0 'If not then make first bit 1 and second bit 0
EndIf
Next counter : serout PORTB.0, n2400, [ $55 , $55 ,$aa , encoded ] 'send out code
write 0, encoded
High 1
Pause 1000
Low 1
goto main


'Receiver Code
Include "Modedefs.bas"
s var byte : B0 var byte : B1 var byte : 's is byte to be encoded, B0 and B1 is byte
counter var byte : cnt55 var byte: 'counter is byte and cnt55 is byte
encoded1 var byte : action var byte : alert var byte : B0=1 : B1=1
'encoded1 word sized variable that holds encoded byte v, alert variable, action variable, B0 and B1 hardwired address
s=0: encoded1=0
main:
cnt55 = 0 'counter for $55 is zero

waitfor55:
serin PORTB.0, t2400, encoded1 'take in data at pin 0 and place in encoded1
if encoded1 = $55 then
cnt55 = cnt55 + 1 '$55 read, increase cnt55 by 1
if cnt55 = 2 then goto waitforaa 'if $55 occurs 3 times in a row check for $aa
else
goto main 'if not $55, reset counter at main and restart
endif
goto waitfor55

waitforaa:
serin PORTB.0, n2400, encoded1
if encoded1 <> $aa then goto main 'restart, incorrect leader bit

serin PORTB.0, n2400, encoded1 : serout PORTB.4, n2400, [encoded1] 'take in from pin 0 to encoded 1 output to pin 3 contens in encoded1
write 0,encoded1
High 7
Pause 10000
Low 7


'Decoding
For counter=0 to 3:s.0[counter]=encoded1.0[counter*2]:Next counter
serout PORTB.3, n2400, [s] 'Ouptut decoded message
write 1, s
High 6
Pause 10000
Low 6

'Tracking code
If (s.2==0) & (s.3==0) Then 'if the code matches 00
If (s.0==B0) & (s.1==B1) Then 'if the address matches then
s.2=1: action = s.2: 'set the third bit to 1 and send it back
alert = 0:
serout PORTB.1, n2400, [s] 'output to pin 1 value in s
Else
s.2=0: action = s.2: 'do not change anything and send back
alert = 0:
serout PORTB.2, n2400, [s] 'output to pin 1 value in s
Endif
Endif

'Tracking and Finding code
If (s.2==0) & (s.3==1) Then 'if code matches 01 then
If (s.0==B0) & (s.1==B1) Then 'If the address matches then
s.2=1: action=s.2: 'set the third bit to 1 and send back
alert=1:
serout PORTB.6, n2400, [s]: 'output to pin 1 value in s
High 2 'set alert to 1 and make pin 2 high.
Else
s.2=0: action=s.2: 'do not change anything and send back
alert=0:
serout PORTB.5, n2400, [s] 'output to pin 1 value in s
Endif
Endif

[skimask]

'Transmitter Code
Include "Modedefs.bas"
main:
v var byte : counter var byte : encoded var byte : v = %1100
'Manchester encoding
For counter = 0 to 3
If v.0[counter]=0 Then
encoded.0[counter*2]=0 : encoded.0[counter*2+1]=1 'If it is a zero make the first bit 0 and second bit 1
Else
encoded.0[counter*2]=1 : encoded.0[counter*2+1]=0 'If not then make first bit 1 and second bit 0
EndIf
Next counter : serout PORTB.0, n2400, [ $55 , $55 , $55 , $55 , $55 , $55 ,$aa , encoded ] 'send out code
write 0, encoded
High 1
Pause 1000
Low 1
goto main


'Receiver Code
Include "Modedefs.bas"
s var byte : B0 var byte : B1 var byte : 's is byte to be encoded, B0 and B1 is byte
counter var byte : cnt55 var byte : cntaa var byte 'counter is byte and cnt55 is byte
encoded1 var byte : action var byte : alert var byte : B0=1 : B1=1
'encoded1 word sized variable that holds encoded byte v, alert variable, action variable, B0 and B1 hardwired address
s=0: encoded1=0
main:
cnt55 = 0 : cntaa = 0 'counter for $55 & $aa is zero

waitfor55:
serin PORTB.0, t2400, encoded1 'take in data at pin 0 and place in encoded1
if encoded1 = $55 then
cnt55 = cnt55 + 1 '$55 read, increase cnt55 by 1
if cnt55 > 3 then goto waitforaa 'if $55 occurs more than 3 times in a row check for $aa
else
goto main 'if not $55, reset counter at main and restart
endif
goto waitfor55

waitforaa:
serin PORTB.0, n2400, encoded1
if encoded1 <> $aa then
cntaa = cntaa + 1
if cntaa > 5 then goto main 'restart, incorrect leader bit
endif
serin PORTB.0, n2400, encoded1 : serout PORTB.4, n2400, [encoded1] 'take in from pin 0 to encoded 1 output to pin 3 contens in encoded1
write 0,encoded1
High 7
Pause 10000
Low 7


'Decoding
For counter=0 to 3:s.0[counter]=encoded1.0[counter*2]:Next counter
serout PORTB.3, n2400, [s] 'Ouptut decoded message
write 1, s
High 6
Pause 10000
Low 6

'Tracking code
If (s.2==0) & (s.3==0) Then 'if the code matches 00
If (s.0==B0) & (s.1==B1) Then 'if the address matches then
s.2=1: action = s.2: 'set the third bit to 1 and send it back
alert = 0:
serout PORTB.1, n2400, [s] 'output to pin 1 value in s
Else
s.2=0: action = s.2: 'do not change anything and send back
alert = 0:
serout PORTB.2, n2400, [s] 'output to pin 1 value in s
Endif
Endif

'Tracking and Finding code
If (s.2==0) & (s.3==1) Then 'if code matches 01 then
If (s.0==B0) & (s.1==B1) Then 'If the address matches then
s.2=1: action=s.2: 'set the third bit to 1 and send back
alert=1:
serout PORTB.6, n2400, [s]: 'output to pin 1 value in s
High 2 'set alert to 1 and make pin 2 high.
Else
s.2=0: action=s.2: 'do not change anything and send back
alert=0:
serout PORTB.5, n2400, [s] 'output to pin 1 value in s
Endif
Endif

Try that out. Send more $55's for the leader (more time for RX to sync up), wait for at least 3 of them. When you get 3, start watching for an $AA. If you don't get an $AA within 5 bytes, restart the process.

As far as changing hex to binary...PBP doesn't care one way or the other. You are working with a byte. PBP can work on bytes, bits, hex, binary, doesn't matter. Just a matter of looking up the right math operator and using it.

[oneohthree]

The encoding and decoding works properly, I have 4 $55's now. I also changed my logic around in my receiver code so that it checks the address (check the first two bits) then determines the mode (checks the last two bits). But, I discover that my microcontroller repeatedly doesn't execute the logic correctly. Even if the first two bits match it always jumps to the statement (indicated by the **** in my code) where it writes to the third memory location in the EEPROM.
I do not understand why it does that.

Receiver code:

Include "Modedefs.bas"
s var byte : B0 var bit : B1 var bit : 's is byte to be encoded, B0 and B1 is byte
counter var byte : cnt55 var byte: 'counter is byte and cnt55 is byte
encoded1 var byte : action var byte : alert var byte : B0=1 : B1=1
'encoded1 word sized variable that holds encoded byte v, alert variable, action variable, B0 and B1 hardwired address
s=0: encoded1=0

main:
cnt55 = 0 'counter for $55 is zero

waitfor55:
serin PORTB.0, t2400, encoded1 'take in data at pin 0 and place in encoded1
if encoded1 = $55 then
cnt55 = cnt55 + 1 '$55 read, increase cnt55 by 1
if cnt55 = 4 then goto waitforaa 'if $55 occurs 4 times in a row check for $aa
else
goto main 'if not $55, reset counter at main and restart
endif
goto waitfor55

waitforaa:
serin PORTB.0, n2400, encoded1
if encoded1 <> $aa then goto main 'restart, incorrect leader bit

serin PORTB.0, n2400, encoded1 : 'serout PORTB.4, n2400, [encoded1] take in from pin 0 to encoded 1 output to pin 3 contens in encoded1
write 0,encoded1
High 7
Pause 2000
Low 7


'Decoding
For counter=0 to 3:s.0[counter]=encoded1.0[counter*2]:Next counter
serout PORTB.3, n2400, [s] 'Ouptut decoded message
write 1, s
High 6
Pause 2000
Low 6


if (s.0=1) AND (s.1=1) then 'Check if address matches
goto L2
else *****
write 3, s
High 2
Pause 2000
Low 2
End
endif


L2:
if (s.2=0) And (s.3=0) then 'if the address Tracking then
s.2=1: action = s 'set the third bit to 1 and send it back
alert = 0: serout PORTB.1, n2400, [action] 'output to pin 1 value in s
write 2, action
High 1
Pause 2000
Low 1
endif

if (s.2=0) AND (s.3=1) then 'If the address Tracking and Finding then
s.2=1: action=s 'set the third bit to 1 and send back
alert=1: serout PORTB.4, n2400, [action]: 'output to pin 1 value in s
write 4, action
High 4
Pause 2000
Low 4
endif

End

[skimask]

if (s.0=1) AND (s.1=1) then 'Check if address matches
goto L2
else *****
write 3, s
High 2
Pause 2000
Low 2
End
endif



Why is there an 'End' in the middle of your code?

[oneohthree]

If the address (first two bits) don't match then I would end the program. I took that out but it seems like it is not advancing towards the correct loop. When my decoded data is stored in the byte s the first bit of my sequence should be coded a s.0 or do I have to define something else before doing s.0?

Include "Modedefs.bas"
s var byte : B0 var bit : B1 var bit : 's is byte to be encoded, B0 and B1 is byte
counter var byte : cnt55 var byte: 'counter is byte and cnt55 is byte
encoded1 var byte : action var byte : alert var byte : B0=1 : B1=1
'encoded1 word sized variable that holds encoded byte v, alert variable, action variable, B0 and B1 hardwired address
s=0: encoded1=0

main:
cnt55 = 0 'counter for $55 is zero

waitfor55:
serin PORTB.0, n2400, encoded1 'take in data at pin 0 and place in encoded1
if encoded1 = $55 then
cnt55 = cnt55 + 1 '$55 read, increase cnt55 by 1
if cnt55 = 4 then goto waitforaa 'if $55 occurs 4 times in a row check for $aa
else
goto main 'if not $55, reset counter at main and restart
endif
goto waitfor55

waitforaa:
serin PORTB.0, n2400, encoded1
if encoded1 <> $aa then goto main 'restart, incorrect leader bit

serin PORTB.0, n2400, encoded1 : 'serout PORTB.4, n2400, [encoded1] take in from pin 0 to encoded 1 output to pin 3 contens in encoded1
write 0,encoded1
High 7
Pause 2000
Low 7


'Decoding
For counter=0 to 3:s.0[counter]=encoded1.0[counter*2]:Next counter
'serout PORTB.3, n2400, [s] 'Ouptut decoded message
write 1, s
High 6
Pause 2000
Low 6


if (s.bit0=0) AND (s.bit1=1) then 'Check if address matches
goto L3
else
write 2,s
High 2
Pause 2000
Low 2
endif


L3:
if (s.bit2=0) And (s.bit3=0) then 'if the address Tracking then
s.bit2=1: action = s 'set the third bit to 1 and send it back
alert = 0: 'serout PORTB.1, n2400, [action] 'output to pin 1 value in s
write 3, action
High 1
Pause 2000
Low 1
endif

if (s.bit2=0) AND (s.bit3=1) then 'If the address Tracking and Finding then
s.bit2=1: action=s 'set the third bit to 1 and send back
alert=1: 'serout PORTB.4, n2400, [action]: 'output to pin 1 value in s
write 4, action
High 4
Pause 2000
Low 4
endif

End

[skimask]

Are you sure that you are receiving at the RX the same thing you are sending at the TX?


'Decoding
For counter = 0 to 3 : s.0[counter] = encoded1.0[counter * 2 + 1] : Next counter

Try that and see what happens...for grins...