Book Scanner (pt 2): The USB Remote and Canon a480

Many canon cameras (a full list here) can be tweaked to allow for a variety of advanced features, including the ability to take pictures via a homemade USB remote. This is made possible when the camera boots special firmware from a SD card. Until recently, this wasn’t available for the Canon A480. Currently, I’m using a second beta version of firmware for this camera–firmware which isn’t quite complete, but does allow for remote control of the camera (this firmware version is free here).

My remote set up

Recall from the previous post:

In my case, when I press the USB button, the camera focuses for the shot. A quick release and repress of the bottom cause the camera to take the picture. The exact voltage heading through the hub to the cameras is 4.74 volts. I didn’t tweak this voltage–it’s simply what resulted in my set up.

Instructions

Since I am a newby to the do-it-yourself book scanner, I went looking for instructions. Here’s what worked for me and what I recommend if you are setting up a Canon a480 [note I am a mac user]:

1. Download the firmware here.

2. Download 0xED (free), to be used later.

3. Prepare your SD card… Format your SD Card with these instructions: [in my case, I used a 4GB SD card]

CHDK requires a card formatted with the FAT16 file system, which is limited to a maximum of 4 GB, to load properly on camera startup.

• Insert an unlocked memory card into a card reader connected to your Mac.

Get the card device name

• Open Disk Utility.
• Select the card reader from the list of devices on the left.
• Get Info ( Apple+I ), and note the Disk Identifier, ie.( /dev/disk2s1 ). This identifier is very important; it will be used to address the proper disk for all subsequent steps. NOTEunder some versions of OSX, the /dev/ part may not be shown in the Get Info window. You will still need to include it in the commands.

We will refer to the disk identifier as /dev/diskXsX from now on. Just replace /dev/diskXsX with the identifier of your disk in all subsequent instructions.

• Be sure that the disk is currently formatted as FAT32 or another MSDOS format. If it is already formatted as FAT16, skip the next steps.NOTE If the card is 2gb or smaller, and has already been formatted in the camera, it is almost certainly FAT16.
• Unmount the partition. Do not eject.

Formatting the card

• Open the Terminal
• Type: sudo newfs_msdos -F 16 -v Canon_DC -b 4096 -c 128 /dev/diskXsX This will reformat a FAT32 disk as FAT16, thus making it compatible with CHDK.
• Enter your password when prompted

4. Next, follow these instructions:

If you don’t want to install darwinports and hexedit, you can also use the free 0xED, or Hex Fiend, which will work with the indirect way as well. This may be the simplest way for a Mac user to get a bootable SD disk.

• Go to the Disk Utility. Select your SD card from the list at the left, and click Informations to get the disk identifier (example: disk4s1). Use this in the steps below
• Using Disk Utility, unmount (don’t eject!) your SD card.
• Open a Terminal window and type: dd if=/dev/disk4s1 of=BootSector_G9.bin bs=512 count=1. This copies a sector of the SD card to your Mac’s hard disk.
• The BootSector_G9.bin file in your Home directory contains your SD card’s boot sector. Make a backup of it in case anything goes wrong.
• Open BootSector_G9.bin with 0xED. Keep in mind that, if you do not see FAT12 or FAT16 around 0x36 (decimal 54) in the hex editor, you probably picked the wrong drive. Do not overwrite anything in that case.
• If the file is correct, select the Overwrite writing method (Command+Shift+O).
• Go to offset hex 40 (decimal 64) and press Tab. Type BOOTDISK. Save and quit.
• In your Terminal window, type: dd if=BootSector_G9.bin of=/dev/disk4s1 bs=512 count=1. This copies the modified file to the boot sector of your SD card.
• Using Disk Utility, mount the card.
• Copy the file DISKBOOT.BIN to the SD card. Make sure to use the correct version for your model of Canon camera.
• Eject the SD card. Slide the tab to the LOCK position

5. Put the SD card in your camera and turn it on. The firmware splash screen should appear.

6. To enable the USB remote, press the “mode” button <alt>, and then the “menu” button <menu>. Go down to “Scripting parameters” and press “set.” Go down to “Remote parameters” and press “set.” Your first option is highlighted: “Enable Remote [ ].” Click “set” and the you’ll see the box marked ( “[•]” ). Press the “menu” button and then the “mode” button. Press the shutter button and you’re ready to roll.

7. Press and hold your USB remote button and the camera will focus and hold for the shot. Quickly release and repress the button and the camera snaps the pic!