how to read ky40 mechanical encoder ?

**iw2fvo** · - 24th October 2015, 18:40

Thanks Richard,
Your program compiles well.
I do have the follwing :

PROGRAM IS STARTING...

32009
32005
32009
32013
32017
32021
32033
32042
32073
32113
32153
32173
32197
32209
32233
32257
32221
32199
32161
32129
32101
32065
32061
32057
32053
32045
32041
32040
32037
32013
31999
31997

I have changed the encoder too but not working...
Thanks
Ambro

**richard** · - 24th October 2015, 20:08

the isr counts edges , an indented re has 4 edges per indent . you would expect to increment counter by 4
don't forget the display routine and the isr are asynchronous .
if you are trying to count indents then

Code:

 cnt_f var bit

Main:
  PAUSE 10

  IF cnt_f THEN

 gosub get_cnt:
     DEBUG DEC counter,13,10
  
  ENDIF
  
GOTO Main





enc_isr:
    ev=ev<<2              ;shift last reading into position
    ev=ev|((portb&48)>>4)  ;read enc pins 4,5  mask off others then  combine this reading with last reading
    LOOKUP (ev&15),[0,255, 1, 0, 1, 0, 0, 255, 255, 0, 0, 1, 0, 1, 255, 0],tmp;lookup the decision matrix
    if tmp then         ; decide to inc , dec or ignore 
        if tmp.7 then
           cnt=cnt-1
           cnt_f=1
        else
            cnt=cnt+1
            cnt_f=1
        endif
    endif
    intcon.0=0                   ; clean up and exit
@ INT_RETURN
    


  
get_cnt :
intcon.3=0
    counter=cnt/4          
    cnt_f=0 
  intcon.3=1 
return