Data processing in array

[Ioannis]

...when the entire process of encoding the bit stream into an unnecessary byte array
of times instead of directly into a bit array on detection would be heaps more efficient...

Sure I agree but could not find a fast way to encode directly the PWM bit stream into bits. The bits are coming from an RF radio receiver and have the typical 66-bit format of a keeloq transmission: 16ms guard time (low), 12 bits of 400us/400us as preamble, a 3-4ms low header and then the 66 bits of the data.

My routine to receive all these bits is based on the PulsIn command in a while-wend loop:

code        VAR byte[9] BANK0   ' PWM read in
code1       var byte[66]            ' Keeloq bits to be decrypted

KEY_0       var byte BANK0
KEY_1       var byte BANK0
KEY_2       VAR BYTE BANK0
KEY_3       VAR BYTE BANK0
KEY_4       VAR BYTE BANK0
KEY_5       VAR BYTE BANK0
KEY_6       VAR BYTE BANK0
KEY_7       VAR BYTE BANK0
mask        VAR BYTE BANK0
CSR_0       VAR BYTE BANK0
CSR_1       VAR BYTE BANK0
CSR_2       VAR BYTE BANK0
CSR_3       VAR BYTE BANK0
pass        VAR BYTE BANK0
CNT1        VAR BYTE BANK0
CNT2        VAR BYTE BANK0

temp        var word

OVER:
while 1
main:
index=0
guard:
    pulsin portb.0,0,temp     'find header of 16ms
    if temp<2500 then main   ' PIC is clocked at 8MHz, so a PulsIn step is 5usec.
    if temp>4400 then main   ' 5usec x 2500= 12.5ms up to 5usec x 4400=22ms
preamp:
    pulsin portb.0,1,temp     'then skip 12 pulses of 50% Duty, 400usec
    if temp<50 then main      
    if temp>90 then main      
    index=index+1
    if index<11 then preamp
         
    index=0 
pulsetrain:                   'now collect 66 pulses ~800/400 usec
    pulsin portb.0,1,code1[index]
    index=index+1
    if index<66 then pulsetrain

    index=0
find_code:  'convert pulse width to binary 66 bit stream
            if code1[index]>130 then
                if code1[index]<170 then
                    code.0[index]=0
                endif
            endif
            
            if code1[index]<80 then
                if code1[index]>55 then
                    code.0[index]=1
                endif
            endif
            
            index=index+1
            if index<66 then find_code
            
            'Display the encrypted and decrypted array
            hserout ["Rec: ",bin2 code[8]," ",bin8 code[7]," ",bin8 code[6]," ",bin8 code[5]," ",bin8 code[4],":",bin8 code[3]," ",bin8 code[2]," ",hex2 code[1]," ",hex2 code[0],13,10]  'display pulse train
            CSR_0=CODE[0]:CSR_1=CODE[1]:CSR_2=CODE[2]:CSR_3=CODE[3]
            GOSUB DECRYPT_K
            hserout ["Dec: ",bin2 code[8]," ",bin8 code[7]," ",bin8 code[6]," ",bin8 code[5]," ",bin8 code[4],":",bin8 CSR_3," ",bin8 CSR_2," ",hex2 CSR_1," ",hex2 CSR_0,13,10,13,10]
            
wend

Obviously, cannot show the DECRYPT_K routine... Sorry.

The above code is not near your fail safe program and will try to fit in the code space after a clean up of the rest code.

Ioannis