Other ports use for interrupt – 665 days old

[19roland70]

I have an electronic circuit with 3 pushbuttons and a display.
I would replace the pushbuttons for an Rotary encoder.
My problem is that the ports B.0 and B.1 are already in use and I can't change the pcb
below a part of the program.

Device = 16F628A   
Config XT_OSC , WDT_OFF, PWRTE_ON, LVP_OFF, BODEN_OFF, MCLRE_OFF
  
All_Digital TRUE              ;Alle ingangen digitaal  
Xtal 4
'---------------------------LCD--------------------------------  
Declare  LCD_DTPin = PORTB.0
Declare     LCD_RSPin = PORTB.4
Declare  LCD_ENPin = PORTA.3
Declare  LCD_Interface = 4  '4-bit Interface
Declare  LCD_Lines = 2
Declare  LCD_Type = ALPHA
Symbol SDA = PORTA.1           'I2C op poort a1   
Symbol SCL = PORTA.0           'I2C op poort a0
Symbol LED = PORTA.2           'ledverl. op poort a2
Symbol ToetsHoger = PORTB.7
Symbol ToetsLager = PORTB.5 
Symbol ToetsSet = PORTB.6 
Dim FREQ_step As Word           'Frequency step
Dim FREQ_khz As Word            'Frequency Khz
Dim FREQ_mhz As Word            'Frequency Mhz
Dim FREQ As Word
Dim TSA_Uitlezen As Word
Dim ADRESS As Byte              'TSA5511 i2c adres
Dim LO As FREQ.LowByte
Dim HI As FREQ.HighByte
EData 2160,2160,2160
PORTA = %00000000               ;PORTA uitgangen bij opstart een laag niveau
TRISA = %11111011               ;PORTA.2 is een uitgang voor de LED
PORTB = %00000000               ;PORTB uitgangen bij opstart een laag niveau
TRISB = %11111111               ;PORTB. is een uitgang voor de LED    
 
Cls
lus:
High LED
Print At 1,1, "FM Test"
Print At 2,1, "W 7 testset"
DelayMS 1000
ADRESS = $C2                    'TSA5511 in adres
FREQ_step = ERead 02            'geheugen lezen voor frequentie in EData
If FREQ_step > 0 Then TSA
'-----------------------------------------------------
Freq_set:
FREQ = FREQ_step
I2COut SDA,SCL,ADRESS,[HI,LO,$8F,$10]        '$8F varicap drive uit 
FREQ_khz = (FREQ_step*10/2)//100
FREQ_mhz = (FREQ_step*10/2)/100
 
Print At 1,1, "Set FM"
Print At 2,1,  Dec FREQ_mhz, ",", Dec FREQ_khz
DelayMS 200
If ToetsHoger = 1 Then Freq_up
If ToetsLager = 1 Then Freq_down
If ToetsSet = 1 Then Freq_save
GoTo Freq_set

'-----------------------------------------UP_freq----------------------------
Freq_up:
FREQ_step = FREQ_step + 1 'step 5
If FREQ_step > 2160 Then FREQ_step = 1750
GoTo Freq_set
'----------------------------------------DOWN_freq--------------------------
Freq_down:
FREQ_step = FREQ_step - 1 'step 5
If FREQ_step < 1750 Then FREQ_step = 2160
GoTo Freq_set
'--------------------------data opslaan---------------------------
Freq_save:
EWrite 02, [FREQ_step]
DelayMS 50

How can I change this ,so I can Use an Rotary encoder.

[Stephen Moss]

How about using a Timer interrupt to read the port pins say every 100mS?

Within the interrupt do something like this...

Rotary_Data_Old = Rotary_Data_New   'Make previous new encoder data value read the new old value
Rotary_Data_New = Portx & %00001110  'Read new rotary value masking off bits not used for the encode (Set bits required to 1, other bits to 0)

Select Rotary_Data_New     'Assign (NOT convert) binary encoder values to sequential decimal values 1 to 6 as the encoder values will be in a grey scale sequence 
         Case = %00000010
            Rotary_Data_New = 1
         Case = %00000100 
            Rotary_Data_New = 2
   'Repeat for as many values as required
EndSelect

I presume this is your current button code...

If ToetsHoger = 1 Then Freq_up
If ToetsLager = 1 Then Freq_down
If ToetsSet = 1 Then Freq_save

If so then change it to something like...

If Rotary_Data_Old = 6 & Rotary_Data_New = 1 then        'Up direction loop around
   Freq_up 
ElseIF Rotary_Data_Old = 1 & Rotary_Data_New = 6 then    'Down direction loop around
   Freq_down 
ElseIf Rotary_Data_New > Rotary_Data_Old                 'Up direction turn
   Freq_up
ElseIf Rotary_Data_New < Rotary_Data_Old                 'Down direction turn
   Freq_down
EndIf

Hopefully that will do what you want.

[towlerg]

B7 is IOC. Personally I never use pins that are part of ICSP, but thats just me.

I can't remember how I did this last time but its something like generate an interupt on one pin and read the other to sus the direction. Maybe this will help, it uses pin that you have here

[flosigud]

You can use IOC to read pins 4 and 5 on portb. That won't interfere with ICSP. There is no setup apart from port settings. RBIE =1 starts the interrupt and the handler can be like this:

If RBIF = 1 Then                        ' On RBIF interrupt
    RBIF = 0
    Swapf PORTB,WREG
    bNew = WREG & 3
EndIff

[flosigud]

I must have been out of my mind when I wrote the above comment. Of cource you have to set up the interrupt or at least decide on which pin it operates. This is how I did it on some ocasion.

    Symbol NOT_RBPU = INTCON2.7
    IOCB = $F0                                 ' PortB 7-4 used
    NOT_RBPU = 0                            ' PortB pullups on

[top204]

A has been stated above, the interrupt on change is extremely useful. Once the interrupt has fired, the interrupt handler can detect which pin it was, of the four, that caused the interrupt.