18F4520 interrupt

[hans]

Hello,
I am trying to read a DTMF module with an interrupt on a 18F4520.pin B4. I found something in the examples. Is thissufficient and  correct? Direct reading of portD_low is working correct. 

-- choose pins to use for int on change
const byte int_on_change_pins[] = {"B",4}
include interrupt_on_change
int_on_change_init()

-- interrupt for pin B4
procedure int_on_change_callback_0() is
   pragma inline
   delay_1mS(400)
   DTMF = portD_low
end procedure

regards

Hans

[hans]

The basic file:

  include 18f4520                     -- target PICmicro
--
-- This program uses the internal oscillator at 4 MHz.
pragma target clock    4_000_000       -- oscillator frequency
--
pragma target OSC      INTOSC_NOCLKOUT           -- internal oscillator
pragma target WDT      CONTROL                   -- watchdog
pragma target XINST    DISABLED                  -- do not use extended instructionset
pragma target DEBUG    DISABLED                  -- no debugging
pragma target BROWNOUT DISABLED                  -- no brownout reset
pragma target FCMEN    DISABLED                  -- no clock monitoring
pragma target IESO     DISABLED                  -- no int/ext osc switching
pragma target LVP      DISABLED                   -- low voltage programming
pragma target MCLR     EXTERNAL                  -- external reset
--
-- The configuration bit settings above are only a selection, sufficient
-- for this program. Other programs may need more or different settings.
--
WDTCON_SWDTEN = OFF                 -- disable WDT
OSCCON_SCS = 0                      -- select primary oscillator
OSCCON_IRCF = 0b110                 -- 4 MHz
OSCTUNE_PLLEN = FALSE               -- no PLL
--
enable_digital_io()                 -- make all pins digital I/O
--

-- DTMF programma
pin_D0_direction       = input
pin_D1_direction       = input
pin_D2_direction       = input
pin_D3_direction       = input
pin_B4_direction       = input -- for interrupt


var byte DTMF

-- choose pins to use for int on change
const byte int_on_change_pins[] = {"B",4}
include interrupt_on_change
int_on_change_init()

-- interrupt for pin B4
procedure int_on_change_callback_0() is
   pragma inline

   pin_C3 = low
   delay_1mS(400)
   DTMF = portD_low
   pin_C3 = high
end procedure

Op vrijdag 23 september 2022 om 14:59:53 UTC+2 schreef hans:

[Matthew Schinkel]

Hi Hans, without me testing or knowing the DTMF module your using. I think it looks ok. It should be easy to test.

Just to make your code easier to read I would alias the pins and directions to useful names. You read code 10 times more than you write it. I don't know what pin_C3 is for, and pin_C3_direction isn't being set.

Looks like your code will wait for an interrupt on pin_B4 then read the lower 4 bits of portd

If the original sample works for you, you can add a sample for 18F4520. The library may need to be modified to support more chips.

Matt.

[vsurducan]

Hans,

I do not see any "pragma interrupt",  it's that OK?

An interrupt procedure needs it no matter the name it has, without it there would be no jump to the ISR interrupt vector.

This line looks strange to me here (but I'm not a master of programming):

const byte int_on_change_pins[] = {"B",4}

BTW, you do not want to use a software delay in an ISR routine, an ISR must be fast by definition because it consumes a period of time which is lost in the main loop. Exceptions for hardware resources of which programming time do not interfere too much with the main loop. Check if your pic has registers to detect which edge is used on interrupt on change. If yes you should program those too.

I hope these would be helpful. In my opinion you should solve the problem by yourself, is the only way you can understand.

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[Matthew Schinkel]

Hi Vasile, he is using the interrupt on change library. It has "pragma interrupt" and needs the strange line "const byte int_on_change_pins[] = {"B",4}".

I agree about the delay, but that depends on the use as you pointed out. It may be ok for the code that is there now, but another way would be to start a timer then when the timer is up use the timer interrupt to read portD_low.

There is also sample 18f4620_interrupt_on_change_pin_b0.jal that shows the use of interrupt on change without using the library.

Matt.

[hans]

Hello,
I tried to use the example in the ample sequence 18F4620 Interrupt on change for the 18F4520. It does not work. What's going on?
regards
Hans

Op zaterdag 24 september 2022 om 07:42:24 UTC+2 schreef mattsc...@hotmail.com:

[hans]

Here is how i have started and having no reslut i did the (wrong??) chnages

-- choose pins to use for int on change
const byte int_on_change_pins[] = {"B",4}
include interrupt_on_change
int_on_change_init()

-- interrupt for pin B4
procedure int_on_change_callback_0() is
  pragma inline

   DTMF = portD_low
end procedure

Op zaterdag 24 september 2022 om 08:07:18 UTC+2 schreef hans:

[hans]

I have changed the program part as follows from the example port B0 , compiling is ok but no result

-- alias the interrupt flags so they are readable.
alias INT_0_ENABLE_BIT is INTCON_INT0IE
alias INT_0_FLAG_BIT is INTCON_INT0IF
alias INT_0_EDGE_BIT is INTCON2_INTEDG0

-- enable global interrupts
INTCON_GIE  = TRUE        -- Enables all unmasked interrupts
INTCON_PEIE = TRUE        -- Enables all unmasked peripheral interrupts

-- define your interrupt pin
alias interrupt_pin is pin_B4
alias interrupt_pin_direction is pin_B4_direction
interrupt_pin_direction = INPUT -- interrupt pin is input
INT_0_ENABLE_BIT = TRUE   -- interrupt pin enable bit for B0
procedure int_on_change_b0() -- procedure is written later

-- main interrupt handler
procedure interrupt() is
   pragma interrupt
   -- Check if interrupt pin 0 (B0) has an interrupt.
   if INT_0_FLAG_BIT then
      DTMF = portD_low
      INT_0_FLAG_BIT = FALSE -- reset interrupt flag
   end if
end procedure

a led on the interrupt pin B4 shows the short blink as soon as a dtmf tone is received. The received value remains on portD-low untill the next tone. So i can read it afterwards. My idea was to wait some time before reading the port.

Op zaterdag 24 september 2022 om 08:08:47 UTC+2 schreef hans:

[Rob CJ]

Hi Hans,

The code looks OK. Maybe as a test you can activate a LED in the interrupt routine to check if it gets there.

What exactly the behaviour?

Kind regards,

Rob

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Van: jal...@googlegroups.com <jal...@googlegroups.com> namens hans <hanz...@zeelandnet.nl>
Verzonden: zaterdag 24 september 2022 08:33
Aan: jallib <jal...@googlegroups.com>
Onderwerp: Re: [jallib] Re: 18F4520 interrupt

 

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[hans]

Hi Rob,

I did already but no result. A led in the interrupt and one on the pinB4. The last one shows the action but the led inside teh pragme not.

 I have now made an procedure which i am calling on several places in my program and it worked.

procedure DTMF_receive is
           if portD_low != DTMF_old then
             DTMF = portD_low
           end if
 end procedure

Op zaterdag 24 september 2022 om 09:45:51 UTC+2 schreef rob...@hotmail.com:

[Rob CJ]

Hi Hans,

I see that this PIC has interrupts with prioirities.

Since you only use interrupt 0 as a regular interrupt can you change this (make FALSE instead of TRUE):

INTCON_PEIE = FALSE 

If I look in the schematic diagram of the datahseet, setting this to TRUE enables the other priority interrupt vector but it does not have any effect on INT0. 

Not sure if it helps but you can give it a try.

Kind regards,

Rob

---

Van: jal...@googlegroups.com <jal...@googlegroups.com> namens hans <hanz...@zeelandnet.nl>

Verzonden: zaterdag 24 september 2022 19:19

Aan: jallib <jal...@googlegroups.com>
Onderwerp: Re: [jallib] Re: 18F4520 interrupt

 

My last try. Loaded in another set. On the output from A 1 shows a led a steady on/off. So also at the entrance of B4. The led on A0 flashes very fast but there is no connection with the input

Op zaterdag 24 september 2022 om 10:39:51 UTC+2 schreef hans:

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[hans]

Hi Rob,

I did with the attached file in another pcd-set with no other things. The led wichh gives the pulses show a regular (1 sec) blink but the output from the interrupt goes on and something off.

Hans

Op zaterdag 24 september 2022 om 20:04:23 UTC+2 schreef rob...@hotmail.com:

[vsurducan]

Hi Hans,

This the way INT1 worked for me on PIC18F26J50, I think your PIC is more or less the same, however each PIC has its own stupidity, so it might not work as expected...

You might want to set the pull-up resistor on your INT pin ( or not, as your schematic requires).

If you are not using dedicated INT pin and your PIC micro has the stupid PPS relocation, it will be additional headache, so check all of these...

good luck!

-- -------interrupt of change IOC-------------------------------------------------------
var bit MY_flag = low
procedure IOC() is
     pragma interrupt
     if INTCON3_INT1IF then
        MY_flag = high
        INTCON3_INT1IF = low
     end if
end procedure

RCON_IPEN = low ; low priority interrupt, PIC16 compatibility
INTCON_GIE = high   ; enable global interrupts
INTCON_PEIE_GIEL = high  ; enable pheripheral interrupts
INTCON3_INT1IE = high    ; enable INT1 on pin_RB5
INTCON2_INTEDG1 = high   ; enable interrupt on rising edge

forever loop

-- use MY_flag for whatever

-- reset MY_flag

end loop

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[hans]

Hi Vasile,

I had pull down on the input, set the pin 5,6 and 7 to output etc....

At Mid night I have changed the input from B4 to B0 and now it works perfect. So what to do if i want to use B4 ??

regards

Hans

Op zondag 25 september 2022 om 08:08:08 UTC+2 schreef vasile:

[vsurducan]

I guess nothing can be done. This pic (if I don't miss anything) has three interrupts on B0, B1 and B2. I don't see any PPS module. BTW I thought seniors are starting at 3am and sleep at midnight...

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[hans]

Hi Vasile,

I've tried to understand page 103, but I shouldn't have. Anyway, an adjustment to my PCB and we happily continue. (to bed on time tonight)
Thanks for all your responses
Hans

Op zondag 25 september 2022 om 10:43:11 UTC+2 schreef vasile:

[vsurducan]

Well, from 102-103 it seems it should work on RB4... try the following pseudocode.

Pin B4 must be set as input and toggled by your hardware.

RCON_IPEN = low ; low priority interrupt,

INTCON_GIE = high   ; enable global interrupts

INTCON_PEIE_GIEL = high  ; enable pheripheral interrupts

INTCON_RBIE = high  ; enable interrupts on change on port B4-B7

var byte MY_data = 0

procedure IOC() is
     pragma interrupt

     if INTCON_RBIF then

        MY_data = port_B 

-- from datasheet page 87: a mismatch condition will continue to set this bit. Reading PORTB will end the mismatch condition and allow the bit to be cleared

        MY_bit = pin_B4

        INTCON_RBIF = low
     end if
end procedure

forever loop

LED = MY_bit

end loop

    

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[hans]

Hi Vasile,

have changed my test program in the same environment ( working with Bo). Pulse now to B4.  but now i see both led continues on. So also the puls is not working.

attached the altered test version.

regArds

Hans

Op zondag 25 september 2022 om 20:34:53 UTC+2 schreef vasile:

[hans]

Sorry mismatch, wrong file part. Change  (, same result both leds ( one together wit pulse))

procedure IOC() is
     pragma interrupt
     if INTCON_RBIF then

        MY_data = portB

-- from datasheet page 87: a mismatch condition will continue to set this bit. Reading PORTB will end the mismatch condition and allow the bit to be cleared
        MY_bit = pin_B4

        led =!led

       INTCON_RBIF = low
    end if

end procedure

Op maandag 26 september 2022 om 10:52:48 UTC+2 schreef hans: