New approach to Rotary Encoder

**Ioannis** · - 28th February 2012, 08:56

a couple of 100nF were needed for mine. After placing the caps to ground from each encoder output pin, false readings were a past.

Ioannis

**fratello** · - 12th April 2012, 09:32

Need help with one enconder ... a little different.
How can I read the "up/+" and "down/-" action of this particular encoder ?
Any help will be appreciated ! Thanks in advance !

**fratello** · - 12th April 2012, 10:39

It's ok something like this ?!

Code:

TrisA = %00000000
TrisB = %11110000
PortB = 0

Flag                var bit
Q_New               var Byte
Q_Old               var byte
M_Count             var byte [4]
P_Count             var byte [4]
Q_Count             var word

' ---------------------- Set variable value @ startup ----------------------  
     
For Q_Old = 0 to 3
Read Q_Old,M_Count[Q_Old]
Read Q_Old + 4,P_Count[Q_Old]
Next Q_Old
     
  Q_Count = 0   
    Q_New = 0
    Q_Old = 0
     Flag = 0  
                        

Goto Main_Loop

Encoder:                                    '
Q_New = PortB.7 + PortB.6 + PortB.5         ' get port status
 
If M_Count[Q_Old] = Q_New then              ' if M_Count code satisfied then minus
          Q_Count = Q_Count - 1
             Flag = 0                       ' set flag for DOWN
goto Q_Skip
endif

If P_Count[Q_Old] = Q_New then              ' if M_Count code satisfied then plus
          Q_Count = Q_Count + 1
             Flag = 1                       ' set flag for UP
endif


Q_Skip:
Q_Old = Q_New                               ' update Q_Old Byte
 

Main_Loop:   
if Flag = 1 then do command1                             
if Flag = 0 then do command2                                  
goto Main_Loop

**fratello** · - 13th April 2012, 08:00

So far...no good

...
Complete "hardware" it's like in picture . I intend to use an remote with some "rotary encoder" ...
The remote controller has six wires . They are connected to three rows and three columns. This allows maximum of 3*3=9 functions. Roller takes three functions because it must be possible to know which way it is rotated (how doing this in PBP ?!?). Rest of the functions are assigned to six buttons.
I use great pice of code (keypad matrix routine) of Mr. Mister-e and the "regular" buttons works verry fine...but I want to use the function of roller too.
I can't figure out how doing this, so any "clue" will be appreciated !

**HenrikOlsson** · - 13th April 2012, 09:52

Hi,
Without analyzing your code in detail one possible problem might be this line

Code:

Q_New = PortB.7 + PortB.6 + PortB.5         ' get port status

In this case you'll get Q_New = 1 no matter WHICH of the three pins are high. I'm not sure but I guess that's not what you want.

You could try something like Q_New = PortB & %11100000 >> 5 instead.

Here's another approach (untested) which is smaller in terms of program space and RAM but like I said it's untested so it might not even work.

Code:

oldState VAR BYTE
newState VAR BYTE
Q_Count VAR WORD
DIR VAR BIT

UP CON 1
DN CON 0

newState = (PortB & %11100000)      ' Isolate top three bits, newState will be 32, 64 or 128 

If newState <> 0 THEN
If newState <> oldState THEN        ' Changed from last time?

  Select Case oldState
    Case 32
    If NewState = 128 THEN          ' Was 1 now 4 = Up
      Q_Count = Q_Count + 1
      DIR = UP
    ELSE                          ' Was 1 now 2 = Down
      Q_Count = Q_Count - 1
      DIR = DN
    ENDIF

  
    Case 64
    If NewState = 32 THEN        ' Was 2 now 1 = Up
      Q_Count = Q_Count + 1
      DIR = UP
    ELSE                           ' Was 2 now 4 = Down
      Q_Count = Q_Count - 1
      DIR = DN
    ENDIF

  
    Case 128
    If NewState = 64 THEN        ' Was 4 now 2 = Up
      Q_Count = Q_Count + 1
      DIR = UP
    ELSE                       ' Was 4 now 1 = Down
      Q_Count = Q_Count - 1
      DIR = DN
    ENDIF

  END SELECT

  oldState = NewState

ENDIF
ENDIF

**fratello** · - 13th April 2012, 10:38

It a real pleasure to see how generous some people can be ... Thank You, AGAIN, Mr. Henrik !
...I think I missing something ... If UP do something, If Down do something else...dont ?!
But nothing happens.

Code:

'****************************************************************
 @ DEVICE pic16F628A, XT_OSC, WDT_OFF, PWRT_ON, BOD_OFF, MCLR_ON, LVP_OFF

   Define   OSC 4           ' 4MHz 
   CMCON = 7                ' Disable on-chip comparator, PORTA in digital mode

include "alldigital.pbp"

TrisA = 000000
PortB = 010000
TrisB = 000000

oldState VAR BYTE
newState VAR BYTE
Q_Count VAR WORD
DIR VAR BIT

UP CON 1
DN CON 0


Main_Loop:  
newState = (PortB & 100000)    
goto encoder
if dir = up then portb.0 = 1                           
if dir = dn then portb.1 = 1 
goto Main_Loop 
goto encoder
if dir = up then 
portb.4 = 1
portb.0 = 1
endif                           
if dir = dn then 
portb.4 = 0
portb.1 = 1
endif
goto Main_Loop


encoder:

If newState <> 0 THEN
If newState <> oldState THEN        ' Changed from last time?

  Select Case oldState
    Case 32
    If NewState = 128 THEN          ' Was 1 now 4 = Up
      Q_Count = Q_Count + 1
      DIR = UP
    ELSE                          ' Was 1 now 2 = Down
      Q_Count = Q_Count - 1
      DIR = DN
    ENDIF

  
    Case 64
    If NewState = 32 THEN        ' Was 2 now 1 = Up
      Q_Count = Q_Count + 1
      DIR = UP
    ELSE                           ' Was 2 now 4 = Down
      Q_Count = Q_Count - 1
      DIR = DN
    ENDIF

  
    Case 128
    If NewState = 64 THEN        ' Was 4 now 2 = Up
      Q_Count = Q_Count + 1
      DIR = UP
    ELSE                       ' Was 4 now 1 = Down
      Q_Count = Q_Count - 1
      DIR = DN
    ENDIF

  END SELECT

  oldState = NewState 

ENDIF
ENDIF

Or I wired the roller wrong ?
Here ( http://www.angelfire.com/nd/maza/kenwood.html ) it's a working variant, but in other "way" , using Atmega ...