@title gentled chdk2 script for zooming and shooting
rem author Dave Mitchell - dave@zenonic.demon.co.uk
rem this script lets a Gentled CHDK2 use two servo channels to control zooming and shooting
rem 
rem This script is designed to work for A-series (which have 8 or 14 zoom steps), SD-series (Ixus/Elph which also have 8 steps)   
rem and S-series (which have 128 steps)
rem In each case it provides for at least 4 zoom positions.
rem 


@param c Camera Series A=0 SD/IXUS=0 S=1
@default c 0

if c<0 then c=0
if c>1 then c=1

rem calculate relative zoom value  
if c = 0 then z =  2 else z = 25

while 1
   do
      a = get_usb_power
   until a>0
   if a <=4 then gosub "ch1up" else if a <=7 then gosub "ch1mid" else if a <=10 then gosub "ch1down" else if a <=13 then gosub "ch2up" else if a <=16 then gosub "ch2mid" else if a <=19 then gosub "ch2down" else print "error"
   endif
wend
end

:ch1up
   print "shoot"
   shoot
   return

:ch1mid
   print "channel 1 middle"
   return

:ch1down
   print "channel 2 down"
   return

:ch2up
   print "zoom in"
   set_zoom_rel z
   return

:ch2mid
   print "channel 2 middle"
   return

:ch2down
   print "zoom out"
   set_zoom_rel -z
   return

return