HAPPy CHDK Intervalometer

--[[
HAPPy Intervalometer script for CHDK written in the Lua programming language.
Version 0.1 Feb 12, 2011
 
This script will configure your Canon camera to auto-focus, take a photo
every x seconds and will record the temperature of the lens, CCD and battery 
to a log file.
The script can be run in Endless mode until the battery or storage space runs out.
 
Authors: Fraser McCrossan and Greg Lawler
 
HAPPy project - High Altitude Photo Project - http://heffrey.com.
A high altitude balloon project which aims to photograph the earth from near space.
 
Features:
 - HAPPy logging - write temperature (C), battery voltage (mV) and timestamp data to log file.
 - Log files located in CHDK/LOGS/
 - Endless mode - will keep taking photos until battery dies or card is full.
 - Turn off the display a given number of frames after starting to conserve battery.
 - Auto focus and expose for each photo.
 
--]]
 
--[[
@title HAPPy Intervalometer
@param s Interval seconds 
@default s 30
@param h Sequence hours
@default h 0
@param m Sequence minutes
@default m 5
@param e Endless? 0=No 1=Yes
@default e 1
@param f Focus: 0=Every 1=Start
@default f 0
@param d Display off frame 0=Never
@default d 5
@param l Enable HAPPy log 1=Yes
@default l 1
--]]
 
-- convert parameters into readable variable names
secs_frame, hours, minutes, endless, focus_at_start, display_off_frame = s, h, m, (e > 0), (f > 0), d
 
props = require "propcase"
 
-- derive actual running parameters from the more human-friendly input
-- parameters
function calculate_parameters (seconds_per_frame, hours, minutes, start_ticks)
   local ticks_per_frame = 1000 * secs_frame -- ticks per frame
   local total_frames = (hours * 3600 + minutes * 60) / secs_frame -- total frames
   local end_ticks = start_ticks + total_frames * ticks_per_frame -- ticks at end of sequence
   return ticks_per_frame, total_frames, end_ticks
end
 
function HAPPy_time()
   yy = (get_time("Y"))
   hh = (get_time("h"))
   if (tonumber(hh)<10) then
      hh = "0"..hh
   end
   mi = (get_time("m"))
   if (tonumber(mi)<10) then
      mi = "0"..mi
   end
   ss = (get_time("s"))
   if (tonumber(ss)<10) then
      ss = "0"..ss
   end
   mm   = (get_time("M"))
   if (tonumber(mm)<10) then
      mm = "0"..mm
   end
   dd   = (get_time("D"))
   if (tonumber(dd)<10) then
      dd = "0"..dd
   end
   hhmmss = hh .. ":" .. mi .. ":" .. ss
   MMYYYY = yy .. "-" .. dd .. "-" .. mm
end
 
function HAPPy_log( i )
  HAPPy_time()
  print_screen( i )
  print( "Picture: "..i )
  print( "Date:",MMYYYY )
  print( "Time:",hhmmss )
  print( "Battery Voltage: ",get_vbatt())
  print( "Lens Temperature:",get_temperature(0))
  print( "CCD Temperature:",get_temperature(1))
  print( "Battery Temperature:",get_temperature(2))
end
 
function print_status (frame, total_frames, ticks_per_frame, end_ticks, endless)
   local free = get_jpg_count()
   HAPPy_log( frame )
   if endless then
      local h, m, s = ticks_to_hms(frame * ticks_per_frame)
      print("Elapsed time: " .. h .. "h " .. m .. "m " .. s .. "s")
   else
      local h, m, s = ticks_to_hms(end_ticks - get_tick_count())
      print(frame .. "/" .. total_frames .. ", " .. h .. "h" .. m .. "m" .. s .. "s/" .. free .. " left")
   end
end
 
function ticks_to_hms (ticks)
   local secs = (ticks + 500) / 1000 -- round to nearest seconds
   local s = secs % 60
   secs = secs / 60
   local m = secs % 60
   local h = secs / 60
   return h, m, s
end
 
-- sleep, but using wait_click(); return true if a key was pressed, else false
function next_frame_sleep (frame, start_ticks, ticks_per_frame)
   -- this calculates the number of ticks between now and the time of
   -- the next frame
   local sleep_time = (start_ticks + frame * ticks_per_frame) - get_tick_count()
   if sleep_time < 1 then
      sleep_time = 1
   end
   wait_click(sleep_time)
   return not is_key("no_key")
end
 
-- delay for the appropriate amount of time, but respond to
-- the display key (allows turning off display to save power)
-- return true if we should exit, else false
function frame_delay (frame, start_ticks, ticks_per_frame)
   -- this returns true while a key has been pressed, and false if
   -- none
   while next_frame_sleep (frame, start_ticks, ticks_per_frame) do
      -- honour the display button
      if is_key("display") then
         click("display")
      end
      -- if set key is pressed, indicate that we should stop
      if is_key("set") then
         return true
      end
   end
   return false
end
 
-- if the display mode is not the passed mode, click display and return true
-- otherwise return false
function seek_display_mode(mode)
   if get_prop(props.DISPLAY_MODE) == mode then
      return false
   else
      click "display"
      return true
   end
end
 
-- switch to autofocus mode, pre-focus, then go to manual focus mode
function pre_focus()
   local focused = false
   local try = 1
   while not focused and try <= 5 do print("Pre-focus attempt " .. try) press("shoot_half") sleep(2000) if get_prop(67) > 0 then
         focused = true
         set_aflock(1)
      end
      release("shoot_half")
      sleep(500)
      try = try + 1
   end
   return focused
end
 
if focus_at_start then
   if not pre_focus() then
      print "Unable to reach pre-focus"
   end
end
 
start_ticks = get_tick_count()
 
ticks_per_frame, total_frames, end_ticks = calculate_parameters(secs_frame, hours, minutes, start_ticks)
 
frame = 1
original_display_mode = get_prop(props.DISPLAY_MODE)
target_display_mode = 2 -- off
 
print "Press SET to exit"
 
while endless or frame <= total_frames do print_status(frame, total_frames, ticks_per_frame, end_ticks, endless) if display_off_frame > 0 and frame >= display_off_frame then
      seek_display_mode(target_display_mode)
   end
   shoot()
   if frame_delay(frame, start_ticks, ticks_per_frame) then
      print "User quit"
      break
   end
   frame = frame + 1
end
 
-- restore display mode
if display_off_frame > 0 then
   while seek_display_mode(original_display_mode) do
      sleep(1000)
   end
end
 
-- restore focus mode
set_aflock(0)