If you’re lofting a digital camera high into the stratosphere with a helium balloon, you really can’t do better than one of those key fob spy cameras. Being extremely lightweight with decent resolution, they’re the perfect camera to take to near space. If you’re bringing someone along to snap the pictures, that is.
[Román] wanted to take his 808 spy camera to new heights, but not wanting to manually reset the thing when it’s 100,000 feet in the air decided to use a microcontroller instead. An 8-pin PIC12F675 takes care of taking 60 pictures with a 4-second interval, then switching to movie mode and recording a 20-second video.
The entire device can be powered by 6 to 9 volts with the help of a voltage regulator. [Román] found the camera hangs after taking about 1600 photos, so a connection from the microcontroller to the reset switch was added. Everything works on the ground, so we can’t wait to see what happens miles above the Earth’s surface.
You do not need the regulator, the camera and micro will run quite readily off a single LiPo cell’s voltage. I have built 7 of these and they all worked fine without regulated voltage. Search for Ghlargh on youtube to see a couple of examples.
Yeah, but at least the regulator keeps the temps up; assuming it needs that anyway.
Why the bizzare 3.8 volts and the HUGE regulator? they have much small regulators out there that would have worked a lot better for keeping everything small and light.
Might be better at keeping everything warm… It gets pretty cold 20 miles up.
good article, cool project!
Yes. It will run with 3.8V… but I don’t have 3,8V on my balloon. But there are others reasons explained in my blog.
And yes, maybe is a large regulator (or not). It disipate 0.5W, it could be manageable by a smaller regulator, but at 100.000 feet there is no air to disipate that heat, all we have to disipate is radiation. I don’t want to blow the most important part!. But the main reason is: I have it. I live in Argentina and find electronical components is very dificult.
You guys have covered a nearly identical project before:
http://hackaday.com/2012/03/29/808-camera-hack-produces-a-time-lapse-tic-tac-box/
It’s a neat project, and very cleanly done. Much neater than my own personal implementation (my implementation used an arduino nano, a second sd card and a gps and it recorded GPS data every time a picture was taken).
Yes Sam, I linked that project in my blog, But this one has some improvements: less components, a way to record video and photos and a reset (to solve some bug I found in two of my three cameras)
I never really had a problem with the camera hanging after 1600 images, but somewhere around there the startup time from sleep becomes rather long. The camera seems to scan the entire file list each startup to figure out what the next number is, the more pictures there are on the card the longer the startup takes. My camera shut down between each picture so after a few thousand images the startup time became ridiculous, like 5s from power on until a picture could be taken.
I’m planning a V2 that will handle this problem by looking at the LEDs as you were too, but other projects came in the way.
Sven,
It’s possible, in one camera I didn’t found the bug. But I’m sure it’s not the lag for the large # files, beacuse even if I use the buttons manually can’t operate it.
Yes, there is no point to turn off the camera after each photo… so I take a secuence of photos, some video and after that I reset the camera (not turn it off).
I had to turn the camera off since it draws over 100mA if it’s on, and i only took one picture every 100s, i would have needed a battery pack the size of a backpack to run it for the time i needed without shutting it down. I assume you are only running yours for an hour or so?
Yes, you are right!… my mistake, I thought your camera was for a high altitude balloon. With a period of 100s you have to turn it off…. well, it will turn itself off in less than a minute. I have another camera (a big one with LCD broken) to time lapse, because the 808 it’s not very good taking photos.
I run my camera for 2 1/2 hours. I’m using lithium battery pack: 5 AA (1A x 3 hours and thats is at room temp); and also I need 150mA for the GPS and 200mA for the UHF transmitter,
How do you turn it off?… with a relay or MOSFET?… I found the voltage drop of a MOSFET is too much for the camera, because that I put it before a voltage regulator.
I “press” the power button to turn it off, i need it connected to power to keep the internal clock.
The video quality of the photos is fine for a casual time lapse video.
If you are getting high voltage drops over a mosfet you are using the wrong type, either too high RDSon, or too high VGSmin. There are several mosfets that can handle at least an amp, and will turn fully on with 3V on the gate.
I’ve got a couple of these keyfob cameras, one I bought to hack in this manner, I got a timelapse setup working on a breadboard ok but didn’t go further because one of one annoying thing – it auto-powers off if you don’t take a picture or video after a while.
Is there a way to stop this thing from automatically going to sleep?
This is great in that it allows a programable sequence of pics and movies.
For less complex applications some of the later 808 models can be configured with the latest firmware to do time lapse and motion detect……cool camera.