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

[CuriousOne]

I have some remotely managed studio strobe, it has keyboard, and when pressing numerical keys, the following sequences being transmitted on single wire, as shown on the picture. What protocol is this, and can I somehow interpret it, using picbasic pro?



Width of wide pulse is 1.9msec, and width of narrow pulse is 642usec.

[Dave]

It looks like some kind of binary coding judging by the number entered and the output stream. Why not ask the manufacture for the protocol?

[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?

[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

[richard]

this works better the first one did no work for sequential 1's

'****************************************************************
'*  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     = %111111    ' Make all pins Input 
trisc     = %101111  ;Make all pins Input   
ANSELA=0     
ANSELC=0
MDSRC=    %00000000
MDCARH   =%11000100
MDCARL   =%00000000
X VAR byte
darta   VAR byte[4] 
TIMER1     VAR WORD EXT
clear
modout var latc.4
darta.0[14]=1 
darta.0[15]=1  
hpwm 1,128,1600
MDCON.0 = 0
modout =0
Main_Loop:
modout=1
pauseus 8000
modout =0
while tmr2 :wend
MDCON=    %11010001
for x = 0 to 31
while tmr2 :wend
  
if  darta.0[x]  then
MDCON.0 = 0
while tmr2 :wend
pauseus 6
while tmr2 :wend
pauseus 6
MDCON.0 = 1
while tmr2 :wend
pauseus 6
else
MDCON.0 = 1
endif
next  
modout=1
MDCON=    0
pauseus 600
modout = 0
PAUSE 200 
goto Main_Loop
end

[richard]

the output

[CuriousOne]

Wow! Such an input.

Here are signal details. Actual signal is high and goes low, on my last picture, I've inverted it just for ease of viewing and analyzing.

On the picture below, I've specified all timings as required.

[richard]

as close as I can get . it has a glitch after the last bit sent

'****************************************************************
'*  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_OFF & _LVP_OFF            
#ENDCONFIG
 
OSCCON=$70 
DEFINE OSC 8
 
'                       PIC 16F1825
 
TRISA     = %011111    ' 
trisc     = %001111  ; 
ANSELA=0     
ANSELC=0
MDSRC=    %00000000
MDCARH   =%01000100
MDCARL   =%00000000
X VAR byte
darta   VAR byte[4] 
TIMER1     VAR WORD EXT
clear
modout var latc.4
darta.0[14]=1 
darta.0[15]=1  
t2con=6
pr2=158
CCPR1L =318>>2
ccp1con=12
MDCON.0 = 0
modout =1
Main_Loop:
lata.5=1 ; cro trigger
while !pir1.1 :wend
modout=0
pauseus 9900
modout =1
pir1.1=0
while !pir1.1 :wend
pir1.1=0
while !pir1.1 :wend
MDCON=    %11000001
pir1.1=0
while !pir1.1 :wend
for x = 0 to 31  
if  darta.0[x]  then
MDCON.0 = 0
pir1.1=0
while !pir1.1 :wend
pir1.1=0
while !pir1.1 :wend
MDCON.0 = 1
pir1.1=0
while !pir1.1 :wend
else
MDCON.0 = 1
pir1.1=0
while !pir1.1  :wend
endif
next 
modout = 1
MDCON = 0

lata.5=0
PAUSE 200 
goto Main_Loop
end

[CuriousOne]

Thanks!

I guess, your code can run on 16F1829 ?

[Art]

Did you try code I posted a month ago, or looked at it to determine it won’t work?
It’s used in an IR remote receiver for a game controller (so has to be reliable)
to interpret exactly the same pulse coded signal, with the timings being the only difference.

[CuriousOne]

No, I haven't used it, because protocol is different from IR protocol.