19.12.2014 - Open-source one year time lapse camera
Sensor: 640x480 UART camera module.
Sample video: http://www.youtube.com/watch?v=aYzQma_5TN0.
RTC (DS1338) included, with CR2032 battery backup.
Stores images on a microSD card, which also holds the config file.
Power is supplied from 4.8+ V, over a 3.3V LDO, so 4 alkalines is ideal. I thought of using a switching regulator to increase efficiency, but it just isn't worth it on this scale - at best you can get 20% increase in run time.
One frame takes:
3 seconds at 100mA for the camera to stabilize and get a picture.
7 seconds at 60mA to write the picture down.
Between frames it stays in deep sleep, consuming 91 uA.
In other words, it uses 3.5-4 joules per picture.
On 4 D cells that would be around 50000 frames - at one frame every 10 minutes it will run for a year, at one per minute - for a month.
The intent is to set it and leave it be, coming back once a year - i like making long time lapse videos.
You can get the schematics and layout here:
Current firmware and MicroSD bootloader:
Appearance of the naked device itself below.
I'm still thinking on what sort of an enclosure to make for it. 3D printing is not going to cut it here. :)