My rotary encoder adventures

[Demon]

It might not have a detent at every quadrature state but it sure must "go thru" them.

Oh definitely. I even see them display on the LCD when I turn my encoder REAL slow.

That's why I had put this comment in my code, to show the CW/CCW progression through the wiper states:

'  Wiper Chart:
'  ============
'     A   B
'    --- ---
'     0   0
'     1   0  /\ CCW
'     1   1
'     0   1  \/ CW
'     0   0
'
' Careful, EC11 30 detents 15 pulses will move from 00 to 11
'          EC11 20 detents can move from 00 back to 00 in one click

No wonder my older EC11 were causing me so much grief in my initial testing.

[Demon]

Here's one of my faster ones:

A is 15.22ms duration
Difference between rise of A and B is 3.50ms
I nearly had time to send LCDOUT twice.




I'm more than satisfied with what I have so far as encoder logic. When I remove LCDOUT, this is how many times the encoder logic can cycle during a fast pulse; a gazillion.




I'm thrilled actually; with a big smile on my face as I type this.

[HenrikOlsson]

Very good, then there's plenty of margin.
Next challenge: Velocity sensing, ie a way to detect that the user wants the value to change by a lot and not have to turn the knob 600 turns. Getting that just right seems to be tricky, even the big boys don't always... (I've never tried).

How will you transfer the count from one PIC to the other? Keep track of your timing, you might be able to do it all with a single PIC. If needed, divide the LCDOutput routine in two (or more) parts if needed.

[Ioannis]

You can experiment with

DEFINE LCD_COMMANDUS 2500

And

DEFINE LCD_DATAUS 50

parameters in order to match your LCD module. Maybe you are lucky and have a faster one. But be carefull as these might not work with all modules.

The Velocity sensing is a really good one. Indeed, if the user has to to change values in a broad range it is very handy. Maybe if Timer is involved can make things simpler.

Ioannis

[Demon]

Very good, then there's plenty of margin.
Next challenge: Velocity sensing, ie a way to detect that the user wants the value to change by a lot and not have to turn the knob 600 turns. Getting that just right seems to be tricky, even the big boys don't always... (I've never tried). ...

That's exactly why I started looking up Elapsed Timer last night. I already have an idea in mind; rotate the encoder at 3 speeds, record the time elapsed between pulses, and then use that to determine if I increment/decrement by ones, fives or tens. I figure with some tweaking I can generate a decent compromise.

I've already adjusted my logic this morning to fall down to 359 when it goes below 0; to better simulate a heading gauge in flight sim, and inverse, flip up to 0 after moving up past 359.

... How will you transfer the count from one PIC to the other? ...

HSEROUT, that's why I had it in my early tests. It compares somewhat with LCDOUT timewise, maybe a tad slower.

I have a lot of R&D to go on that subject (like protocol and such).

... If needed, divide the LCDOutput routine in two (or more) parts if needed.

Nah, I have a LOT of controls to manage. I'm putting encoders as priority on a PIC, then switches and pots separately (ADC probably takes forever in comparison), and 4 LCDs wherever I have room and time available.

This is a preliminary layout; 3 enclosures: left, center and right . The right side has the most encoders with:

- 4 dual encoders
- 7 single encoders
- 1 mouse wheel (essentially a single encoder)

Those Custom Keys in the middle are just a reminder for a 4th optional enclosure at far left.





The thin red stripes are LED stripes; shielded towards the controls to simulate a red glow, like this:

[rocket_troy]

Very good, then there's plenty of margin.
Next challenge: Velocity sensing, ie a way to detect that the user wants the value to change by a lot and not have to turn the knob 600 turns. Getting that just right seems to be tricky, even the big boys don't always... (I've never tried).

I'm in the middle of a project requiring a rotary encoder to set a weight target for a loadcell. I plan on using Richard's graphical LCD driver for a dot matrix display (not superfast update refreshing), so I actually needed something like what you've described there Henrik. Using Demon's code, I twiddled it a bit to utilise (elapsed) Timer0 on an 18F26K22 to provide the screen refreshing. This is what I basically came up with (which I'm happy with):

'REMOVED ALL THE INIALIZATION STUFF FOR THIS PASTING

Enc1_counter = 1000

SETFONT FONT5x7
'SETFONT bignum5
LATC.4 = 0 'using a pic pin output as a temporary ground rail for the rotary encoder
gosub grf_clr

T0CON.7 = 1 'enable timer 0
T0CON.6 = 0 'timer 0 in 16 bit mode
T0CON.5 = 0 'timer 0 clock source = internal instruction clock
'T0CON.4 
T0CON.3 = 0 'timer prescaler assigned
T0CON.2 = 0 ' prescaler assigned to 1:4
T0CON.1 = 0 ' "
T0CON.0 = 1 ' "

Timer_Counter = 0
Change = 0

MainLoop:
    Timer_Counter.lowbyte = TMR0L
    Timer_Counter.highbyte = TMR0H    
    New_Encoder = (PortB.4 << 1) + PortB.5

    IF New_Encoder != Old_Encoder THEN
        IF New_Encoder = %00000011 THEN
            IF Old_Encoder = %00000010 THEN
                Change = Change+1
                Enc1_counter = Enc1_counter + Change 
            ELSE
                IF Old_Encoder = %00000001 THEN
                    Change = Change+1
                    Enc1_counter = Enc1_counter - Change      
                ENDIF
            ENDIF
        ELSE
            IF New_Encoder = %00000000 THEN
                IF Old_Encoder = %00000001 THEN
                    Change = Change+1
                    Enc1_counter = Enc1_counter + Change  
                ELSE
                    IF Old_Encoder = %00000010 THEN
                        Change = Change+1
                        Enc1_counter = Enc1_counter - Change    
                    ENDIF
                ENDIF
            ENDIF
        ENDIF
    ENDIF
    
    if change >= 1 and Timer_Counter>60000 then
        TMR0H=0
        TMR0L=0 
        ARRAYWRITE BUFF,[sdec Enc1_counter,0]
        gosub grf_clr
        'DMDSTR 10,10, BUFFp,1
        DMDSTR 10,10, BUFF,1
        gosub show
        Change = 0
  else
        pause 5
    endif
    
    Old_Encoder = New_Encoder

goto MainLoop:

Troy