Multi-Button CSM with Pic16LF722A

[richard]

in this example I use indirect addressing to retrieve the data ,but due to the 12f1822 architecture only the low 8 bits are retrievable .wastes a bit of space but its heaps quicker

'****************************************************************
'*  Name    : ws2812.BAS                                                                              *
'*  Author  : richard                                                                                       *
'*  Notice  :                                                                                                   *
'*          :                                                                                                     *
'*  Date    : 1/11/2016                                                                                  *
'*  Version : 1.0                                                                                            *
'*  Notes   : pic12f1822  @32 mhz 3v3                                                           *
'*          : porta.5 >>>> ws2821 Din                                                             *
'****************************************************************
 #CONFIG
cfg1 = _FOSC_INTOSC
cfg1&= _WDTE_ON
cfg1&= _PWRTE_OFF
cfg1&= _MCLRE_ON
cfg1&= _CP_OFF
cfg1&= _CPD_OFF
cfg1&= _BOREN_ON
cfg1&= _CLKOUTEN_OFF
cfg1&= _IESO_ON
cfg1&= _FCMEN_ON
  __CONFIG _CONFIG1, cfg1

cfg2 = _WRT_OFF
cfg2&= _PLLEN_ON
cfg2&= _STVREN_ON
cfg2&= _BORV_19
cfg2&= _LVP_OFF
  __CONFIG _CONFIG2, cfg2

#ENDCONFIG

 bt VAR byte  bank0
 px VAR byte  bank0
 pc var byte bank0   ; number of rgb led to write x3

 pixels  var byte[3]    ;  rgb led  x3
 DURATION  var byte
 
 palette var word    ;address of pallet
 TEMP VAR WORD
 OFFSET VAR WORD     ;pallet index


 
 
   
 goto overpalette   ; green,red,blue data   
 my_palette:     ;  note !!!  inde read can only access the low byte of each  stored  word
 @ dw 100,120,0  ;
 @ dW 0,100,0  ; RED
 @ dW 0,80,0  ;
 @ dW 0,60,0  ;
 @ dW 0,20,0  ;
 @ dW 200,200,0  ;OR
 @ dW 160,160,0  ;
 @ dW 100,100,0  ;
 @ dW 80,80,0  ;
 @ dW 2,5,0  ; 
 @ dW 200,150,0  ;YEL
 @ dW 160,120,0  ;
 @ dW 100,75,0  ;
 @ dW 80,60,0  ;
 @ dW 40,30,0  ; 
 @ dW 150,200,0  ; ?
 @ dW 120,160,0  ;
 @ dW 75,100,0  ;
 @ dW 60,80,0  ;
 @ dW 30,40,0  ; 
 @ dW 120,100,0  ;
 @ dW 160,160,160  ; WH
 @ dW 100,100,100  ;
 @ dW 80,80,80  ;
 @ dW 30,30,30  ;
ASM  
 

;---[Returns the Address of a Label as a Word]------------------------------
GetAddress macro Label, Wout
    CHK?RP Wout
    movlw low Label          ; get low byte
    movwf Wout
    movlw Label >> 8         ; get high byte
    movwf Wout + 1
  endm     
endasm
overpalette :  
 
 goto overasm
   asm
_pram                     ;entry point to read from sram
        movlw   low _pixels
        movwf   FSR0L
        movlw   high _pixels
        movwf   FSR0H 
        goto _nxby
_prom                     ;entry point to read from flash 
        CHK?RP _OFFSET
        MOVE?WW   _OFFSET , FSR0
        BSF FSR0H ,7
_nxby   MOVIW  FSR0 ++
        movwf _px
        MOVLW 8
        movwf _bt
        RLF _px,F
_nxbt   BSF LATA ,5
        BTFSS STATUS,C
        GOTO XX
        NOP
        NOP
        NOP
XX      BCF  LATA ,5
        NOP
        RLF _px,F
        DECFSZ _bt,F
        GOTO _nxbt 
        DECFSZ _pc,F
        GOTO _nxby
        RETURN 
   
endasm

overasm:



 CLEAR
 define OSC 32
 osccon=$f0
 trisa=%011110
 @ GetAddress _my_palette,_palette  ;set pallet address
 
 
loopy: 
 GOSUB FLICKER
 PC=3    ; value is  number of rgb leds X 3 
 call prom
 pause DURATION
 goto loopy
 
 
 
 
FLICKER:
 RANDOM TEMP
 DURATION=TEMP&$7F
 RANDOM TEMP
' temp=0
 OFFSET =(TEMP //25)*3 + palette
RETURN

[richard]

you can toggle on/off like this

IF KP = 0 THEN '1/0 BUTTON PRESSED
;use p_level to see what state machine is in 0=off ,non zero = on
if p_level then
ccp1con=0 ;must be on kill it
led=0
p_level= 0
else ;must be off power to max
p_level= 5
endif

stoping it repeating too quickly is a bit trickier
a pause that's long enough to allow reaction time would do , its a bit klunky.
the best way is to wait for the key to be released before acting (or repeating the action)
maybe counting three passes through main loop with flg=0 after an I/O key press would indicate key is released
and its safe to re-enable the key

[richard]

since the isr TB1 is an accurate timebase you can
make a new var

 kio_inhibit var byte

modify the I/o key routine

IF KP = 0 THEN '1/0 BUTTON PRESSED
        ;use  p_level to see what state machine is in  0=off ,non zero = on
        if kio_inhibit==0 then
           kio_inhibit=152    ;152*32mS = about 5 seconds
        if  p_level then     
            ccp1con=0 ;must be on kill it
            led=0
            p_level= 0
        else         ;must be off  power to max
            p_level= 5
        endif
       endif

and add this to the isr

if kio_inhibit then
    kio_inhibit =  kio_inhibit -1
    endif

now the I/O key is inhibited for 5 sec after being acted on

I like ART's quote and its so true

PBP is very well documented, however you’ll notice all examples of command use are also examples of exactly how not to write a cyclic program.

you need to adjust your way of thinking to loops , states and flags . it opens up a whole new vista

[RWright]

Wow, you are awesome. I'll have to try it out to see what it does. Thanks!

[RWright]

Hello again,

Was that timestamp of 3:12 as in 3:12AM?! I did the modification as above. It works like you explained. It doesn't cycle now, but the 5-second delay is way too long to be able to
power it up again. If I change the kio_inhibit value to a shorter value, will it just end up cycling again? Is there a means that if the 1/0 button is released it resets the counter to zero so that the button can be used immediately again? The long delay is fine for when the button is being held for an extended period of time. Thanks!

[RWright]

Hello again!

Just curious as to why there isn't any reference to the PR2 register in the program, for setting up the PWM? If I wanted to increase the pwm frequency to 25Khz, I take it I would have to go to a higher oscillator frequency and use different prescaler values?! Thanks.

[richard]

Just curious as to why there isn't any reference to the PR2 register in the program, for setting up the PWM?

flicker is virtually invisible to the human eye for switching frequencies above 50 Hz, switching losses increase with frequency , other than that the frequency is irrelevant .
fine control of the pwm frequency is possible using pr2 at the expense of resolution . since the frequency is largely irrelevant why not have maximum resolution

If I wanted to increase the pwm frequency to 25Khz, I take it I would have to go to a higher oscillator frequency and use different prescaler values?

depends on required resolution, @4mHz 25kHz is possible with 1:1 prescale and pr2=39 , however maximum duty occurs @ pwm_duty_reg = 160 , ie pw range is 0 to 160 (instead of 0 to 1023 steps as before)

[Aussie Barry]

Hi All,

Has anyone had any experience with a 2 channel CSM slide switch?
I would like to implement a slide switch rather than an up / down button arrangement to select the PWM output for a LED string.
In my case, the granularity is quite coarse - only eight steps of PWM selection.

Any input would be greatly appreciated.

Cheers
Barry

[RWright]

Hello,

Regarding the flicker, you know this and I know this, however, we are trying to match an existing product that is set at 25khz. It appears at lower frequencies
it is causing their power supply to make audible noise at the PWM frequency. And sure enough, at 1khz, at certain pwm levels, we can hear it in the power supply. I don't have to keep the oscillator at 4khz, but I assume making any changes to the main Oscillator will also affect the touch circuit, as well. I did see in the pwm section of the datasheet that the resolution drops depending on the oscillator frequency after I posted this. Thanks again!

[RWright]

Sorry for the repeated post.