Darrels interrupts and multiple SOUND statements, will it work?

[CuriousOne]

Gives same error on 12F1840.

[HenrikOlsson]

Hi,

> What happens if I run this code say at 4mhz 16F870 ? there will be no output, frequency wont match, or sound will be breaking up?

There's not enough time to actually execute the interrupt service routine before the timer fires another interrupt. The CPU will spend all of its time in the ISR, no time left for you to set the desired frequencies etc and the output frequenices will be wrong and...... Simply - It just won't work. You need 16MHz.

> on 16F876A, gives error during compile on this:
> IPR1.1 = 1 ' TMR2 high priority

The 16F series doesn't have interrupt priorities, remove the line.

> Gives same error on 12F1840.

The 12F series doesn't have interrupt priorities, remove the line.

/Henrik.

[CuriousOne]

Still does not compile on 16F876A -

ASM ERROR:
Symbol not previously defined (wsave), (ssave), (psave).

Compile OK on 12F1840, but ASM warning - Found label after column 1. (Generate), Extraneous arguments on the line

[CuriousOne]

added this for 16F876A:

wsave VAR BYTE $20 SYSTEM
ssave VAR BYTE $22 SYSTEM
psave var byte $24 SYSTEM

Have no idea why, but no more errors in compile, will try runtime shortly.

[CuriousOne]

It works, sort of (20mhz crystal 16F876A).

If any channel duration has same value, these channels won't play.
Also, playback duration is different each time, it might play 4 or 5 times same duration, then 2 times shorter duration, then again normal.
It works properly only when value of output timings is first is the shortest, 2nd medium and 3rd - longest. If in reverse, it will only play last, short one.

[HenrikOlsson]

Hi,

> Still does not compile on 16F876A -
> ASM ERROR:
> Symbol not previously defined (wsave), (ssave), (psave).

Do you have DT-Ints in the program? I thought I said:

You can not cut'n'paste this into a program using DT-Ints. Try it stand-alone first and we'll see about DT-ints later - if needed.

> Compile OK on 12F1840, but ASM warning - Found label after column 1. (Generate), Extraneous arguments on the line
That's a warning, have you edited the source in any way? I don't get that here.....

> If any channel duration has same value, these channels won't play.
> Also, playback duration is different each time, it might play 4 or 5 times same duration, then 2 times shorter duration, then again normal.
> It works properly only when value of output timings is first is the shortest, 2nd medium and 3rd - longest. If in reverse, it will only play last, short one.

Are you running the program, by itself, on the 16F877 at 20MHz or are you, despite my warning, trying to run it together with the rest of your program AND DT-INTS?

/Henrik.

[richard]

any pic without auto context save will need the wsave psave vars added


this compiles ok for a 12f1822 watch the define OSC not sure how fast a 12f1822 is

'****************************************************************
'*  Name    : 3xSound generator.pbp                             *
'*  Author  : Henrik Olsson                                     *
'*  Notice  : Written by Henrik Olsson 2015                     *
'*          : Free software, use as you wish.                   *
'*  Date    : 2015-01-14                                        *
'*  Version : 1.0                                               *
'*  Notes   : Written in response to a thread on the PBP forum: *
'*          : www.picbasic.co.uk/forum/showthread.php?t=19684   *
'*                                                              *
'*          : Tones are generated using the DDS tecnique with a *
'*            simple 16bit accumulator to which a value gets    *
'*            added once every interrupt (100us). When the      *
'*            accumulator overflows the output is toggled.      *
'*            Three generators are incorporated since that was  *
'*            the request. More could be added if the PIC is    *
'*            clocked fast enough. With three generators 16MHz  *
'*            is the lowest you want to use. The interrupts     *
'*            then uses ~70% of the available CPU cycles when   *
'*            three tones are generated.                        *
'*                                                              *
'*            Version history:                                  *
'*              v1.0 2015-01-14 - Initial version               *
'*                                                              *
'****************************************************************
' CONFIG's, TRIS's, ANSEL's CMCON's and anything device specific is not shown
DEFINE OSC 20
DEFINE INTHAND _Generate         ' We're treating the interrupt as an ASM routine (see notes!)   did not like asm label not sure why
'-------------------------------------------------------------------------------------------
' These variables and alises are needed by the sound generator and needs to be
' accessed by the user.
Channel_1       VAR Porta.0     ' Output for sound channel 1
Channel_2       VAR Porta.1     ' Output for sound channel 2
Channel_3       VAR Porta.2     ' Output for sound channel 3
TMR2IF          VAR PIR1.1      ' Alias to TMR2 Interrupt Request Flag - verify against datasheet.
Output_1        VAR WORD        ' Desired output frequency, Channel 1, 13.107 units per Hz
Output_2        VAR WORD        ' Desired output frequency, Channel 2, 13.107 units per Hz
Output_3        VAR WORD        ' Desired output frequency, Channel 3, 13.107 units per Hz
Duration_1      VAR WORD        ' Duration of tone, Channel 1, 100us units.
Duration_2      VAR WORD        ' Duration of tone, Channel 2, 100us units.
Duration_3      VAR WORD        ' Duration of tone, Channel 3, 100us units.
'-------------------------------------------------------------------------------------------
' These are variables used by the interrupt service routine.
' No user servicable parts inside......
R0_SHADOW       VAR WORD        ' Variable used for saving PBP system variables in the ISR
R1_SHADOW       VAR WORD        ' Variable used for saving PBP system variables in the ISR
R4_SHADOW       VAR WORD        ' Variable used for saving PBP system variables in the ISR
Accumulator_1   VAR WORD        ' DDS accumulator for sound generator 1
Accumulator_2   VAR WORD        ' DDS accumulator for sound generator 2
Accumulator_3   VAR WORD        ' DDS accumulator for sound generator 3
old_1           VAR WORD        ' Used to detect overflow of accumulator 1
old_2           VAR WORD        ' Used to detect overflow of accumulator 2
old_3           VAR WORD        ' Used to detect overflow of accumulator 3
'--------------------------------------------------------------------------------------------
' We want 10kHz interrupt rate, that's 100us between interrupts.
' The interrupt routine needs around ~280 instruction cycles when
' outputting on three channels.
'
' At 16MHz that would be  400 instructions - 70% used by the generator. 
' At 20MHz that would be  500 instructions - 56% used by the generator
' At 40MHz that would be 1000 instructions - 28% used by the generator
' At 64MHz that would be 1600 instructions - 17.5% used by the generator
'
' T2CON and PR2 needs to be setup so that an interrupt is triggered every 100us
' Use one of the follwing:
' PR2 =  99 : T2CON = %00000110   ' For 64MHz - 1:16 prescaler
' PR2 =  49 : T2CON = %00000110   ' For 32MHz - 1:16 prescaler
' PR2 = 124 : T2CON = %00000101   ' For 20MHz - 1:4 prescaler
' PR2 =  99 : T2CON = %00000101   ' For 16MHz - 1:4 prescaler
 
PR2 = 99 : T2CON = %00000110  'TMR2 on, postscaler 1:1, prescaler 1:4
'IPR1.1   = 1        ' TMR2 high priority
PIE1.1   = 1        ' TMR2 IE
INTCON.6 = 1        ' PIE
INTCON.7 = 1        ' GIE

Main:
    ' All three notes will play simultanously for the specified duration.
    ' The sound is generated in the background so the PAUSE 1000 will
    ' execute at the same time as the notes are played. Remember though that
    ' the interrupt "steals" time so the PAUSE isn't correct. The slower the
    ' PIC clock is the more inacurate it gets.
    Output_1 = 857   : Duration_1 = 500    'Play C2 (65.4Hz) for 50ms
    Output_2 = 5767  : Duration_2 = 2500   'Play A4 (440.0Hz)for 250ms 
    Output_3 = 25893 : Duration_3 = 1000   'Play B6 (1975.5Hz) for 100ms
    Pause 1000
Goto Main

'-------------------------------------------------------------------------------
' Actual interrupt routine here. Please note that this is written in PBP but
' the interrupt is handled as if it were a ASM interrupt. As far as I can see
' it uses PBP system variables R0, R1, R4 so I'm saving/restoring those.
' If ANY code gets added here then the ASM-listning needs to be checked to 
' see of the added PBP code uses any more system variables and if so
' those needs to saved/restored as well.
' When all three channels produces output it needs ~280 instructions cycles.
Generate :                       made this a pbp label
@ MOVE?WW R0, _R0_SHADOW                  ; Save PBP system variable R0 
@ MOVE?WW R1, _R1_SHADOW                  ; Save PBP system variable R1 
@ MOVE?WW R4, _R4_SHADOW                  ; Save PBP system variable R4   
    TMR2IF = 0
    IF Duration_1 > 0 THEN
        Accumulator_1 = Accumulator_1 + Output_1
        If Accumulator_1 < old_1 THEN Toggle Channel_1
        old_1 = Accumulator_1
        Duration_1 = Duration_1 - 1
    ELSE
        Channel_1 = 0
    ENDIF
    
    IF Duration_2 > 0 THEN
        Accumulator_2 = Accumulator_2 + Output_2
        If Accumulator_2 < old_2 THEN Toggle Channel_2
        old_2 = Accumulator_2
        Duration_2 = Duration_2 - 1
    ELSE
        Channel_2 = 0
    ENDIF
    
    If Duration_3 > 0 THEN
        Accumulator_3 = Accumulator_3 + Output_3
        If Accumulator_3 < old_3 THEN Toggle Channel_3
        old_3 = Accumulator_3
        Duration_3 = Duration_3 - 1
    ELSE
        Channel_3 = 0
    ENDIF

@ MOVE?WW _R0_SHADOW, R0                    ; Restore PBP system variable R0
@ MOVE?WW _R1_SHADOW, R1                    ; Restore PBP system variable R1 
@ MOVE?WW _R4_SHADOW, R4                    ; Restore PBP system variable R4    
 
@ retfie                           ; '    no fast

[HenrikOlsson]

Thanks Richard!
Didn't think about the lack of auto context save on the 16F parts, thanks for picking that up!

Yes, the 12F1822 can run at up to 32MHz from its internal oscillator and it has the auto context save - it would be a good choice for this, as said before.

CuriousOne,
Please try Richards edited version on your 12F1822 and see if it works.

/Henrik.