Is it possible to interpret non-standard serial data with PicBasic (sample attached)

[Heckler]

hi dave,

it reminds me of a sort of binary encoding...
0= no missing pulse 0000
1= 1 missing pulse in the "ones" position 0001
2= 1 missing pulse in the "twos" position 0010
3= ones missing and twos missing 0011
4= 1 missing pulse in the fours position 0100
5= ones and fours missing 1001

it would help to see all the way up to 9
do you also need to decode other letter/function key/enter/backspace etc. etc. characters??

I don't recognize the protocol off hand but then I am no protocol expert.

perhaps some sort of digital logic analyzer that has a good interpreter behind it would help.
something like this... https://www.saleae.com
I have never used the saleae but I know it comes highly regarded for it's price.

good luck

[CuriousOne]

Yes is goes up that way, I can record it up to 9, but you are correct, it looks like plain BCD code, but the rendering of "0" and "1" with pulses, looks weird for me. I have saelae logic analyzer, but it can't detect these pulses at all, I've used scope to record them.

In fact, I want very simple thing - say, set variable ENABLE=0, when "zero" is transmitted, and ENABLE=1, when any other digit is being sent. I'm not looking for character decoding or whatsoever.

[CuriousOne]

I was suggested, that this is PPM (Pulse Position Modulation), used in some IR/RF remotes and telemetric control equipment. Datasheet of Holtek HT6222 shows quite similar, but not exact diagram of signal.

[pedja089]

If you need only ENABLE use count to count pulses.
Try something like this:

COUNT Pin, Period, Var
If Var<xxx then
    enable=1
else 
    enable=0
endif

[CuriousOne]

But pulses are of different width in series, will it work?

[CuriousOne]

Just checked, it works, but not as it should - even on same sequence, it always reads different values.

taki:
COUNT PORTC.4, 70, LABEL
if label=0 then
goto taki
endif
LCDOUT $FE,$c0, DEC(LABEL), "          "
PAUSE 5
GOTO TAKI

[pedja089]

try this:
taki:
While PORTC.4=0
WEND
COUNT PORTC.4, 70, LABEL
LCDOUT $FE,$c0, DEC5 LABEL
PAUSE 5
GOTO TAKI

[richard]

well the dsp module is interesting but for this project perhaps its easier to do it the old way

'****************************************************************
'*  Name    : MODULATOR.BAS                                     *
'*  Author  : [select VIEW...EDITOR OPTIONS]                    *
'*  Notice  : Copyright (c) 2016 [select VIEW...EDITOR OPTIONS] *
'*          : All Rights Reserved                               *
'*  Date    : 5/29/2016                                         *
'*  Version : 1.0                                               *
'*  Notes   :                        *
'*          : 16F1825                                           *
'****************************************************************
  #CONFIG
             __config        _CONFIG1,    _FOSC_INTOSC & _CP_OFF & _WDTE_ON  &  _PWRTE_ON  &  _MCLRE_ON  & _CLKOUTEN_OFF
              __config      _CONFIG2, _PLLEN_ON & _LVP_OFF            
#ENDCONFIG
 
OSCCON=$70
DEFINE OSC 32



'                       PIC 16F1825



TRISA     = %001111	   ' Make some pins Input 
trisc     = %001111  ;Make some pins Input   
ANSELA=0     
ANSELC=0



X VAR byte
darta   VAR byte[4] 


    clear
    
    modout var latc.4
    darta.0[14]=1 
    darta.0[15]=1 

   
    modout =1
    lata.5=0    ;cro triger
Main_Loop:
    lata.5=1
    modout=0
    pauseus 9900
    modout =1
    pauseus 1880
    for x = 0 to 30 
        modout =0
        if  darta.0[x]  then    
            pauseus 2000
        else
            pauseus 780 
        endif
        modout =1
        pauseus  635 
    next
    modout =1
    lata.5=0
    PAUSE 200 

goto Main_Loop
end