PICDIM Lamp Dimmer for the PIC12C508 - PICREF-4

[mister_e]

O.k

all you need to know @50Hz

Period : 20 ms
1/2 period :10 ms

i'll prefer to detect begining of each cycle using the appended circuit...

You must detect begining of cycle, then activate output to TRIAC for a maximum delay of 10ms including when your PIC is detecting the begining of the cycle. Let's say your PIC is detecting the cycle after 1ms of the begining, you must wait a maximum of 9 ms. Can be intelligent to use a PIC who have internal voltage comparator here.


try the following code as a begining.

'Using PIC16F628
@ __config _INTRC_OSC_NOCLKOUT & _WDT_ON & _PWRTE_ON & _MCLRE_ON & _LVP_OFF 

TRISB=%00000001

BeginingCycle    var PORTB.0
OutputToTriac    var PORTB.1
delay            var byte
Hold             var word

while BeginingCycle
wend
start:
For delay=0 to 8
     for Hold=1 to 100
          while BeginingCycle=0
          wend
     
          OutputToTriac=1
          Pause delay
          OutPutToTriac=0
          While BeginingCycle
          Wend
     Next
next

goto start