CHDK coding on my IXY Digital 70

Decided to have a play around with CHDK scripts available for my camera, and saw that the coding was very easy to follow. So I decided to create my own using some minor pieces from the example scripts provided on the CHDK wiki.

CHDK Screen

I wanted a script that would continuously take photo's for the duration of the flight and would require minimal fiddling around to start. By this I wanted to reduce/remove  any button clicks that may result in a setting being changed pre-launch that could jeopardize the mission.

Below is the code I have started with. It has the following features.  Note that it works with my Canon IXY Digital 70 and may not suit all camera's.

• Sets a 1st shot delay. No point going all snap happy with the box still on the ground.
• Variable shot interval
• Logging of camera internal temperature and battery voltage to SD card.
• Saw this as a backup temp data logger for the flight
• Disable flash.
• Couldn't find a single command for this so had to create a loop that pressed the flash button until it was off.
• Disables LCD screen.
• Read in the script manual, that the screen automatically resumes when you take a picture. For the screen to be turned off you must also allow for the picture to be written to SD card otherwise the screen will just come back on again. I saw this happening so added the 'sleep 500' to give it enough time to save.

Happy for any comments and tips, as its my first CHDK script so I'm sure there may be improvements I can make.


<davCam.bas>


@title DavCam
@param a interval (sec)
@default a 12
@param d Delay 1st Shot (sec)
@default d 20
@param n fileNum
@default n 1

if a<5 then a=5
a=a*1000
if d<1 then d=1
d=d*1000

print "Script will run"
print "until interrupted"
gosub "disFlash"
playsound 1 
sleep d
cls

print_screen n
print get_time 4;"/";get_time 3;"/";get_time 5;" ";get_time 2;":";get_time 1;":";get_time 0
print " "
print "Time,Optics Temp,CCD Temp,BattmV"

o = get_day_seconds

:main
    gosub "getData"
    gosub "takePic"
    set_backlight 0
    sleep a
    rem set_backlight 1
goto "main"

:takePic
    set_zoom 0
    do
        get_zoom z
    until z = 0
    shoot
    sleep 500
    return

:getData
    print (get_day_seconds - o);",";get_temperature 0;",";get_temperature 1;",";get_vbatt;
    return

:disFlash
    f=get_flash_mode
    while f<1
    click "right"
f=get_flash_mode
sleep 500
    wend
    print get_flash_mode
    return

:restore
    set_backlight 1
    end

So far I have set the camera to launch the script when powered on. So hopefully when the launch commences its a matter of pressing one button and that's it.

I haven't looked into exposure settings yet, as I don't really know what will be best for high altitudes. So maybe people reading this may have some ideas.

Camera Trials 2

After placing the CHDK software on my IXY Digital 70, I quickly realized that the software didn't remain active after a power down. No big deal, but for the launch it needs to be active at power on.

Simply followed the Make SD Card Bootable steps and it seems to have done the trick.

Installed one of the Intervalometer scripts and have been playing around with it and some other settings.
I am looking for a script that will allow the camera to take photo's continuously at a set interval and so far this script seems to do that.  I just need to tweak it so the camera runs at its lowest power consumption. Which means I need to work out how I can shoot with the LCD off.

Also need to get myself a larger SD card for the camera. I tried an 8 GB card and the camera didn't recognize it, so I'm hoping its just the type of card and not a size thing. The current card I have is only 1 Gig and with my current tests I max the card out before the battery runs flat. When I set the quality to minimum I seem to get about 1.5 hours of battery life.  I'd assume that using high res shot would take a little more out of the battery then a lower res, but either way I will have to look at a battery expansion.

Will have to open the camera up and attach an external battery pack

Garmin GPS18 PC - First test

It took a couple of weeks to arrive but my Garmin GPS18 was finally delivered. I couldn't wait to test it out, but don't have a GPS tracker yet, so had to use my laptop.

The GPS pictured below comes with a cig lighter plug and a sticker stating it will work with 8v - 30v.. I plan on removing the cig lighter plug and connecting directly to a portable power source. So I will need to run a few tests to determine what sort of battery I need. Obviously I need something that will last the duration of the flight and the recovery phase.

The serial connection will allow direct attachment to the GPS Tracker when I receive it, but for my first test it needs to connect to my laptop. As modern technology would have it my laptop doesn't have any serial ports. But this isn't a problem as I have a serial to USB adaptor which does the conversion.

Successfully downloaded the Garmin Web updater software and was able to update the firmware. So far so good. I then searched for some GPS software to test things out and found OziExplorer which I have used many years ago with a previous Garmin.

Had to set the GPS type and comm port details, as well as untick the USB GPS box, then I was in action. Had the GPS sitting inside on the window, so GPS signal was at first low, but after a few minutes the GPS updated and I had a signal fix.   Phew , it works...

Will hunt for a GPS Data Logging app so that I can just log the raw data, Maybe go for a drive around with it connected to the laptop and see what it picks up.

Camera Trials - Installing CHDK on IXY Digital 70CHDK Menu

Been really eager to get into some testing and recently received an E-Bay purchase of a Canon IXY Digital 70 camera. So now that I have it I plan to mod it with the CHDK tool and see what its capable of. Camera was really cheap but will be a great initial est unit. It may make the flight if the tests are good.


Here are the steps I am taking to get the CHDK tool working on the camera. May come in handy for other experimenters.

1. I followed the FAQ on the CHDK site, which gets you to create an empty ver.req or vers.req on the cameras SD card. With the SD card inserted I just hold the Func and Disp buttons and the version is displayed.  Though I did do this first I then also found another tool that does all the work for you.

Found a tool called ACID on the FAQ page which just with a simple photo it will tell you what you need to run CHDK. This is what I ended up doing.

After running ACID I simply took a photo with the camera and dragged it into the App and got the below results.

My results running ACID

 Ticked the download stable CHDK full build and clicked the Download stable CHDK. The app then downloads and extracts into a Stable CHDK folder into the apps working directory.

2. Next I read the Preparing SD Card FAQ which gives more detail and a few other methods, but really all I did was copy the files downloaded to the SD card, in playback mode , choose firmware upgrade from the camera's playback menu. It then asks for confirmation to upgrade and it was that easy.

Following the upgrade I was able to press the printer button and the CHDK menu appears

CHDK Menu

First steps complete.  Now to have a play around and check out some scripts to see what this puppy can do  :-)

Edit :- Since doing some testing I have realized that you need to make the SD card bootable so that the CHDK tool will be available when you first turn the camera on.

Congratulations Felix

Congratulations to Felix Baumgartner and his team with the successful supersonic dive from a High altitude balloon. Can't image the time and effort that would have gone into the planning and organisation of such a fee. Makes my balloon project look petty.

Red Bull Stratos

Spot Satellite GPS Tracker

I decided to have a look at the Spot GPS tracker for the use in my High Altitude Balloon. My brother has been using one successfully when hiking for some time now, so I know they are a capable device. But how well do they suit my balloon project.

Spot Device from - http://www.findmespot.net.au

The Spot devices seems to be priced around AU $140 - $200 depending on where you purchase, plus you have to pay an annual service fee for the tracking. If I had other uses for the spot device outside of HAB then the extra cost might be worth while. So currently APRS still looks like my preferred option.

The Spot GPS device has great potential for tracking the payload when its in the recovery phase. I have read that the Spot GPS Device does not function at high altitude, thus not ideal for tracking the entire mission.

Once activated the Spot Device will transmit its location every 10 mins, for a 24hr period. This data can be view on the spot website, which makes it very easy for friends to follow along too.

Pros :-

Compact and light weight. (approx 147g)
Uses Satellite, so should work almost anywhere.

Cons :-

Annual Service fee (May be worth it for some people)
Does not function at high altitude above approx 80000ft. (Read this from several people)

Found a few people that use Spot devices in their projects.

• High Altitude Balloon Project 2010 and their Spot Page
• UCSD Near-Space Balloon
• Beaufort High School have some great pictures of the Spot Device in their payload.

A good launch

Found this clip, which gave some good tips



Pacific Star II from Colin Rich on Vimeo.

I specially love some of the stills take.

Trial GPS Receiver

Did some hunting around on Ebay for a GPRS receiver and came across a Garmin GPS 18 PC receiver. Decided to make the purchase after reading about it's success with another HAB project. I will use this to experiment with APRS on the ground first and if all goes well may send it into the sky.

Its supposedly a 010-00321-34 GPS 18x PC Receiver , which seems to be on the list of high altitude GPS's.

Will probably test it on a laptop first, as I don't have a APRS tracker yet. So stay tuned.