Camera Flash Trigger showing assembly Interrupts within PBP

[BobP]

Hello All,

This is a program to control a camera slave flash.
Triggered from the cameras own inbuilt flash.

The program is very small demonstrating the use of assembly interrupts in PicBasic Pro.
This program uses Interrupt On Change on a single bit of the GPIO port.

'****************************************************************
'*  Name    : UNTITLED.BAS                                      *
'*  Author  : Bob Simpson                                       *
'*  Notice  : Copyright (c) 2009 Bob Simpson                    *
'*          : All Rights Reserved                               *
'*  Date    : 07/02/2009                                        *
'*  Version : 1.03                                              *
'*  Notes   :                                                   *
'*          :                                                   *
'****************************************************************

'
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
'  PIC Defines
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
'
@ DEVICE pic12F683, INTRC_OSC_NOCLKOUT
        ' System Clock Options
@ DEVICE pic12F683, WDT_Off
        ' Watchdog Timer
@ DEVICE pic12F683, PWRT_ON
        ' Power-On Timer
@ DEVICE pic12F683, BOD_OFF
        ' Brown-Out Detect
@ DEVICE pic12F683, MCLR_OFF
        ' MCLR external ON for enabled
@ DEVICE pic12F683, IESO_ON
        ' Internal osc start-up 
@ DEVICE pic12F683, FCMEN_OFF
        ' OSC fail detect Detect
@ DEVICE pic12F683, CPD_OFF
        ' Data Memory Code Protect
@ DEVICE pic12F683, PROTECT_OFF
        ' Program Code Protection

DEFINE OSC 8                ' PIC will run at 8Mhz so tell PBP
DEFINE  INTHAND intcamera   ' Tell PBP that there is an interrupt routine

'
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
'  Port Setup
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'
INTCON = 0          ' Disable the global interrupt
OSCCON=%01110001    ' Internal 8 Mhz clock
ANSEL=0             ' All Port A is Digital
CMCON0=%0000111     ' Comparators off
VRCON.7=0           ' Power down comparators
CMCON0=7            ' Power down voltage Ref  
TRISIO=%111000      ' GPIO bit 0,1 and 2 are outputs rest inputs
WPU=%010000         ' Pull-up for GPIO.4 selected
OPTION_REG.7=0      ' Enable internal pull-ups
IOC =%010000        ' Interrupt on change selected for GPIO.4

'
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
'  Variables and Names Setup
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'
    wsave   VAR	BYTE bank0 system	' Saves W
    ssave   VAR	BYTE bank0 system	' Saves STATUS
    psave   VAR BYTE bank0 system 
    TRIG    VAR	BYTE bank0          ' Not used yet 
    B1      var BYTE                ' Temp store
    FTrig   VAR GPIO.4              ' Input from LED 
    LCAMERA VAR GPIO.1              ' Output to low voltage trigger
    HCAMERA VAR GPIO.0              ' Output to High voltage trigger

    CLEAR                   ' Clear all variables	
    GoTo mainloop           ' jump over the interrupt handler 

'
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
'  Interrupt Routine
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'
Asm
intcamera 
; Save W, STATUS and PCLATH registers
    movwf wsave
    swapf STATUS,W
    clrf STATUS
    movwf ssave
    movf PCLATH,W
    movwf psave

; Trigger Camera output on flash ip
    bsf     _LCAMERA        ; Set output to 1
    bsf     _HCAMERA        ; Set output to 1
    clrf    _TRIG           ; Clear tick store (For future changes. Not used yet)
    MOVF    GPIO,W          ; Read Port to clear IOC flag
    bcf     INTCON, GIE     ; Clear Global interrupt flag in INTCON register  
    bcf     INTCON, GPIE    ; Clear port change interrupt enable flag in INTCON register  
    bcf     INTCON, GPIF    ; Clear interrupt flag in INTCON register  

endint
; Restore PCLATH, STATUS and W registers
    movf psave,W
    movwf PCLATH
    swapf ssave,W
    movwf STATUS
    swapf wsave,F
    swapf wsave,W
    retfie
 
EndAsm
 
'
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
'  Main Program Starts Here
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'
MainLoop:
    INTCON=0                ' Disable all interrupts and PortA IOC
    LCAMERA=0
    HCAMERA=0
    B1=GPIO                 ' Read port to ensure no setting of IOC flag
    INTCON =%10001000       ' Enable the RA port change interrupt
    NAP 5                   ' Sleep till portA change. Watchdog switched off 
    PAUSEUS 4               ' Give everything time to settle down

FlashTriggered:
    INTCON =0               ' Disable interrupts. 
    pause 500               ' Wait 1/2 second with outputs switched on. Remember outputs have been switched on in the assembler interrupt routine
    LCAMERA=0
    HCAMERA=0               ' Now switch both outputs off
    GOTO MainLoop

END

I am no PicBasic Pro Guru, that mantel is firmly in the hands of others.
But the program is very small with frequent comments and hopefully there are no major mistakes?
Also attached is a zip file contains the information to make a Slave Flash Trigger.

The flash unit has performed over the past 2 weeks with no problems.

Regards,
Bob

[b1arrk5]

Very nice Bob! I've got a few 'peanut' slaves in my bag and they are handy, but I think I'll have to build one of yours to play with. I like the idea of being able to trip two flashes simultaneously, without needing two slaves.
If you want to see pricey accessories, check out the Pocket Wizards. They are professional level radio slaves, and will take a big bite out of your wallet.

Thanks for sharing this,

Jerry.

[grounded]

nice job BobP
I built some of these back a few years ago for my game camera
lot cheaper that store bought stuff
thanks for sharing
cheers