PASM - Dimmer Triac Driver code help
lanternfish
Posts: 366
I have been playing around with the Dimmer Triac Driver Object from the OBEX.
What I want to achieve is an inverted output i.e. the driver currently is active high output; I want to an active low output.
The object begins:
And then I changed the :loop0 line below:
To:
And further into the object:
I changed :loop2 to:
And then at the end of the code:
I changed:
to:
Using a quickstart board I have assigned port 16 to the output/triac driver pin and port 23 to for the zero crossing (active high) input.
While the original code works the modified doesn't.
Q1. What have I done wrong?
My "duh" in advance.
Cheers
What I want to achieve is an inverted output i.e. the driver currently is active high output; I want to an active low output.
The object begins:
PUB Load (BrightnessAt)
'' Call this routine with address of brighness variable.
'' The brighness variable should be set from 0-255, 0=full off, 255=full on.
'' BrightnessAt is address of variable to pass to PASM code to set the brighness (0 - 255)
ZeroPin := |< CrossDetect ' bit mask for Zero Crossing Detector Pin (Active High)
OutputPin := |< Output ' bit mask for Output Pin (Active High)
BrightVarAt:=BrightnessAt ' Push address of brighness into PASM code
cognew(@Dimmer,@Stack)
DAT
{
Enter with the ADDRESS of the LONG that contains the brighness level.
The brightness level can be any value but it is looking for 0 = full off to 255 = full on.
If the value is less than 0, it is set to 0.
If the value is greater than 255, it is set to 255
}
And then I changed the :loop0 line below:
org 0
Dimmer
mov St1,OutputPin ' Set all bits for input except output pin
mov dira, St1
:loop0 mov outa,#0 ' *** Turn OFF output
To:
:loop0 mov outa,#OutputPin ' *** Turn ON output
And further into the object:
:loop1 '' Look for leading edge of zero crossing input
mov st3,ina ' Read input value
and st3,ZeroPin wz ' Mask off all but input bit
if_z jmp #:loop1 ' Bit not high, do it again
rdlong st1,BrightVarAt
maxs st1,#255
mins st1,#0
mov st3,#255 ' Invert because delay makes light dimmer
sub st3,st1
'' See if full on, if so, skip delay
cmp st3,#0 wz
if_z jmp #:loop2
'' See if full off, if so, skip delay
cmp st3,#255 wz
if_z jmp #:loop3
'' Calculate number of clock cycles to delay for 0-255 level
'' 100% on time = 80_000_000 / 120 = total of 666_667 clock cycles (666_667/255 = 2614 counts/bit)
'' Our full on = 2048+512+32+16=2608 clock cycles per level (2608*255=665_040 total clock cycles)
mov st1,st3 ' 80Mhz / (1/256 x 1/120) = 2604 clock cycles per half cycle
shl st3,#11 ' level x 2048 (2614 - 2048 = 566)
mov st2,st1
shl st2,#9 ' level x 512 (566 - 512 = 54)
add st3,st2
mov st2,st1
shl st2,#5 ' level x 32 (54 - 32 = 22) ' error of 22/2614 = insignificant but not 100% on
add st3,st2
mov st2,st1
shl st2,#4 ' level x 16 (22 - 16 = 6) ' error of 6/2614 = insignificant but not 100% on
add st3,st2 ' so if level = 255, skip timing and turn on immediately.
add st3,cnt ' Delay until this clock value is reached
'' Check to see if main delay value is reached
waitcnt st3,#0 ' Wait until main count time is reached, time to turn on Triac
:loop2 mov outa,OutputPin ' *** Turn ON output pin
I changed :loop2 to:
mov outa,#0 ' *** Turn OFF output pin
And then at the end of the code:
:loop3 '' Look for trailing edge of zero crossing input
mov st3,ina ' Read input value
and st3,ZeroPin wz ' Mask off all but input bit
if_nz jmp #:loop3 ' Bit high, do it again
:loop4 '' Look for leading edge of zero crossing input to go HIGH again to start next cycle
mov st3,ina ' Read input value
and st3,ZeroPin wz ' Mask off all but input bit
if_z jmp #:loop4 ' Bit not high, loop until cycle ends
'' Done with this half cycle, do it again
mov outa,#0 ' *** Turn OFF output pin
jmp #:loop0
ZeroPin long 0 ' Pin number for Zero-Crossing Pulse (Active High)
OutputPin long 0 ' Pin number for output to MOC3010M
BrightVarAt long 0 ' Address of brighness variable
ST1 res 1 ' Temp 1
ST2 res 1 ' Temp 2
ST3 res 1 ' Temp 1
fit 496 ' Make sure it fits within a cog's memory space
I changed:
'' Done with this half cycle, do it again
mov outa,#0 ' *** Turn OFF output pin
jmp #:loop0
to:
'' Done with this half cycle, do it again
mov outa,#OutputPin ' *** Turn ON output pin
jmp #:loop0
Using a quickstart board I have assigned port 16 to the output/triac driver pin and port 23 to for the zero crossing (active high) input.
While the original code works the modified doesn't.
Q1. What have I done wrong?
My "duh" in advance.
Cheers
Comments
Yes, the dreaded #.
Once again you have helped me. Thank you.