Index:
	01 - Introduction & Camera Specific Notes

	02 - Installation

	03 - FAQ

	04 - Links, Urls

	05 - GPL, License

	06 - uBASIC copyright notice


************************************


01 - Introduction

Hi, 

this is the small readme to CHDK. It provides just enough info to get you rolling, for more information use the links in the bottom.


CHDK is a firmware enhancement that operates on a number of Canon Cameras. CHDK gets loaded into your camera's memory upon bootup (either manually or automatically). It provides additional functionality beyond that currently provided by the native camera firmware.

CHDK is not a permanent firmware upgrade: you decide how it is loaded (manually or automatically) and you can always easily remove it. 

Main features:

    * Save images in RAW format
    * Ability to run "Scripts" to automate the camera
    * Live histogram (RGB, blended, luminance and for each RGB channel)
    * Zebra mode (blinking highlights and shadows to show over/under exposed areas)
    * An "always on" full range Battery indicator
    * Ability to turn off automatic dark-frame subtraction
    * a higher compression movie mode, and double the maximum video file size
    * exposure times as long as 65 seconds
    * exposure times as little as 1/10,000 of a second
    * ability to use the USB port for a remote trigger input 

Additional features:

    * a depth-of-field (DOF)-calculator
    * File browser
    * Text reader
    * Calendar
    * Some fun tools and games 

Why would I want to use CHDK?

    * To get Raw file capability on cameras that don't have that ability
    * To get the ability to use scripts
    * to be able to know the battery status at all times (not just when it's about to run out of power)
    * you want or need any of the other enhancement features that CHDK provides 

What are scripts? Scripts are Lua or uBASIC language programs that give you the ability to control the operation of the camera under program control. They have been used to add or extend the native capability of the camera: more flexible intervalometers, extended-range exposure compensation, extended bracketing ability, lightning photography, etc. See the script pages for more details.


*** Build Information ***
CHDK for g7x fw:100d PID:12957
build:1.7.0-6343 date:Sun, 21 Sep 2025 04:57:15 +0200

*** Camera specific notes ***
************************************
G7 X notes
************************************
CHDK is a hack, use at your own risk!

While this port is relatively mature, Digic 6 has significant differences
from previously supported models, which means some features are not fully
implemented and the risk of unforeseen side effects is higher than ports for
previous Digic versions.

The VER.REQ/VERS.REQ method does not work to obtain the Canon firmware
version, use ACID or the firminfo Canon Basic script.

No "firmware update" file is included in the autobuild, you must used
bootable SD card to load. See known bugs below.

General camera and CHDK port information
****************************************
G7 X has an adjustable aperture and ND filter

SD override does not work in AF, only MF or AF lock

Default alt button is PLAY. VIDEO and WIFI may also be used

The RING FUNC key is identified as ERASE in scripting and CHDK shortcuts

The half press zebra shortcut keys is MENU

To start in shooting mode or wifi connect, hold down the corresponding button

Raw blacklevel appears to be ~511, not the ~127 seen on other 12 bit cams

G7 X uses propset 7. The values used in some propcases have changed, which
can break compatibility with scripts.

Only simple_movie_status is implemented, so features or scripts that rely on
direct access to the movie_status variable do not work

HDMI hotplug, analog AV detect, and battery temperature A/D are supported
as alternate remote inputs.

G7 X can boot CHDK from cards formatted FAT32 or FAT16, but not exFAT. Cards
larger than 32 GB generally default to exFAT and must either be re-formatted
FAT32 or partitioned with a FAT16 boot partition to enable CHDK autoboot.
Using an exFAT partition for images is reported to give better performance
with large cards.

TESTED
******
llibtst.lua
chdkptp cam tests
PTP play/rec switch
raw and remote hooks (in normal still shooting modes, broken some special modes)
ND override
SD override
Tv, Av and bracketing
ISO overrides and bracketing
 - may have issues, full range not tested, some unexpected results in cont mode.
setmode.lua - crashes with default 10ms delay, works with 100ms
ubtest.bas
hooktest.lua
isobase.lua
USB remote - plug test / remote hook only
CHDK raw / DNG - In most still modes that take a single exposure, see Known Bugs below
PTP remote shoot with JPEG, CHDK DNG and Canon raw (with chdkptp r964 or later)
 - Fails in modes that take multiple exposures: Canon firmware bracketing,
   HDR, Creative shot etc
Motion detection - Note version of mdfb2013.lua up to 1.1a is not compatible
PTP live view - Requires client with live view proto 2.2 support
 (chdkptp r712 or later)
Dark frame control
 - If set to auto Canon firmware uses DFS for tv 5-30 sec, depending on ISO and temperature
Multipartition boot with FAT16 + exFAT

NOT IMPLEMENTED
***************
video controls (movie_rec task)
extra long exposures (exp_drv task)
 - Canon firmware supports up to 250 sec
reboot with firmware update file
script hard shutdown (shut_down(1))

OTHER ISSUES
************
Zebra thresholds need to be adjusted to around 26 for zebra to display

PROPCASE_RESOLUTION values differ from previous models
- 0=L (20MP) 2=M1 (12MP) 3=M2 (4MP) 5=S (720x480) (sizes at 3:2 aspect)
PROPCASE_IS_MODE values differ from some previous
- 0=Continuous, 1=Shoot Only, 2=Off.
  Setting other values (as done by mdfb2013.lua up to 1.1a) causes crash on shutdown.

KNOWN BUGS
**********
- CHDK raw and remote hooks are not called in some special shooting modes (HDR, star trails etc)
  This means script shoot() calls, scripts that use shoot hooks and synced remote do not function
  correctly in these modes. This mostly affects modes that take multiple exposures for a single jpeg
- CHDK raw / DNG may not work correctly in some other special scene modes
- When booted with FI2 update
 - switching to hybrid auto causes a crash
 - orientation sensor value alternates between 0 and 90
 Because of these issues, an FI2 file is not included in the autobuild
- When using remote shoot, DCIM directories will be created even if no files are saved
- On multi-partition cards, the CHDK "Make Card Bootable" option does not make the make
  the FAT16 boot partition bootable

THANKS
******
* srsa_4c for the sx280hs port, and doing all the hard work to support digic 6.
* 62ndidiot and Ant for solving many generic digic 6 display issues
* kitor, srsa_4c, Philmoz and Ant for developing the ximr display code, which
  solves many display issues which affected earlier digic 6 ports
* The anonymous donor who provided the camera.
********************************

02 - Installation

To install CHDK on your Canon P&S camera,  you need to know the model number and firmware version of your cameras in order to get the right version of CHDK for your camera  Details on how to determine this can be found here :

http://chdk.fandom.com/wiki/Downloads


Once you have the correct CHDK installation file for your camera,  you need to prepare and load your camera's SD card with CHDK.  The best method for doing this depends on how you intend to use your camera and the date your particular carmera was released.  Details can be found here :

http://chdk.fandom.com/wiki/Prepare_your_SD_card

Once you have correctly loaded CHDK,  you can refer to the following section for instructions on how to use CHDK.

****************************************

03 - FAQ

1. What is CHDK?

    CHDK is not just one thing! The term CHDK refers to free software currently available for many (but not all) Canon PowerShot compact digital cameras that you can load onto your camera's memory card to give your camera greatly enhanced capabilities. 

2. Am I likely to be interested in CHDK?

    The enhanced capabilities that CHDK provides are most likely to be of interest to experienced photographers - if you believe that your Canon PowerShot camera already has more features than you will ever need, you probably won't be interested in CHDK. 

3. Is CHDK safe to use?

    Yes CHDK is experimental and has risks, but with tens of thousands of happy users it can generally be considered safe. CHDK doesn't make any actual changes to your camera. If you delete the CHDK software from your memory card, or if you choose not to activate the CHDK software on the card (or remove and replace the batteries), then the camera will behave absolutely normally - nothing has been (or ever is) changed, so the warranty is not affected. 

4. How does CHDK work?

    CHDK makes use of the microprocessor that controls the camera (every digital camera contains a microprocessor) to act as a programmable computer that provides the extra capabilities. 

5. What extra capabilities does CHDK provide?

    The current set of extra capabilities fall into six categories:

        a. Enhanced ways of recording images - you can capture still pictures in RAW format (as well as JPEG), and for video images you can have increased recording time and length (1 hour or 2 GB), and a greatly increased range of compression options. 
        b. Additional data displays on the LCD screen - histogram, battery life indicator, depth of field, and many more. 
        c. Additional photographic settings that are not available on the camera by itself - longer exposure times (up to 65 seconds), faster shutter speeds (1/25,000 sec, and faster in some cases), automatic bracketing of exposure, etc. 
        d. The ability for the camera to run programs ('scripts', written in a micro-version of the BASIC language) stored on the memory card - these programs allow you to set the camera to perform a sequence of operations under the control of the program. For example, a camera can be programmed to take multiple pictures for focus bracketing, or take a picture when it detects that something in the field of view moves or changes brightness. 
        e. The ability to take a picture, or start a program on the memory card, by sending a signal into the USB port - you can use the USB cable to take a picture remotely. 
        f. The ability to do a number of other more useful (and fun) things, such as act as a mini file browser for the memory card, let you play games on the LCD screen, etc. 

6. What else should I know?

    Developers around the world are continuing to add new features to CHDK. Because the idea of using the camera's microprocessor is so flexible, various developers have made different versions of CHDK, and new features continue to be developed - for example, one version of CHDK has features assist in taking stereo photographs, and even allows two cameras to be synchronized to take pictures at the same time (with an accuracy of better than 0.1 milliseconds, providing they are the same camera model). 

The best place to find out more about CHDK is to follow the CHDK wiki  ( http://chdk.fandom.com/wiki/CHDK ) and CHDK user forum ( http://chdk.setepontos.com/ ).




********************************

04 - URLs, Links


For more information visit the following links:

CHDK Forum :                    http://chdk.setepontos.com/index.php

CHDK Wiki:                      http://chdk.fandom.com/wiki/CHDK
CHDK Wiki FAQ:                  http://chdk.fandom.com/wiki/FAQ

CHDK Features :                 http://chdk.fandom.com/wiki/CHDK_User_Manual#Introduction
CHDK in Brief :                 http://chdk.fandom.com/wiki/CHDK_in_Brief
CHDK User Quick Start Guide :   http://chdk.fandom.com/wiki/CHDK_User_Quick_Start_Guide.pdf
CHDK User Manual :              http://chdk.fandom.com/wiki/CHDK_User_Manual
CHDK for Dummies :              http://chdk.fandom.com/wiki/CHDK_for_Dummies
CHDK Installation Guide :       http://chdk.fandom.com/wiki/File:CHDK_Installation_Guide.pdf

One Page Users Guide :          http://chdk.fandom.com/wiki/One_Page_Ultra-Quick_Users_Guide

Prepare Your SD Card :          http://chdk.fandom.com/wiki/Prepare_your_SD_card




*********************************

05 - GPL


/*
 * This file is part of CHDK.
 * Copyright (C) 2008 The CHDK Team
 * CHDK - CHDK Wiki
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA,
 * 02110-1301  USA
 */

*********************************

06 - uBASIC copyright notice

CHDK contains a modified version of Adam Dunkels uBASIC. 

The following notice applies to the original uBASIC code:

Copyright (c) 2006, Adam Dunkels
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.
3. Neither the name of the author nor the names of its contributors
   may be used to endorse or promote products derived from this software
   without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.

