HAPPy CHDK Intervalometer

HAPPy Intervalometer script for CHDK written in the Lua programming language.

This script will configure your Canon camera to auto-focus, take a photo every x seconds and will also 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.

By Greg Lawler, based on work by Fraser McCrossan.

This script was built for my work on the HAPPy (High Altitude Photo Project) balloon project at http://happycapsule.com – a high altitude balloon project which aims to photograph the earth from the stratosphere.

HAPPy Intervalometer Features:
– HAPPy logging – write temperature (C), battery voltage (mV) and timestamp data to log file.
– Log files written every time the shutter clicks.
– 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.

As I build scripts to graph and process the log data, I will post them here.

Download
HAPPy Intervalometer for CHDK – version 0.1 (zip)
HAPPy Intervalometer for CHDK – version 0.1 (tar.gz)

Source Code:

--[[
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)