Friday, 25 January 2013

Battery life

the dip at the end of the red line is the GoPro battery giving out. Nearly 8 hours at one frame every twenty seconds - it needs to be better than that, so the camera battery is going to need to be topped up between shots.

The voltage drop on the big battery looks concerning... maybe I forgot to charge it?

To help the arduino it may be powered from the switch mode regulator on the power board via the USB.

Could try putting it to sleep for a few seconds, this may upset the timer. (use the RTC for image/logging times?)

The debug LED's will be taking a little bit a current too.

Before fucking about it might be prudent to get an meter across the NiMH current output...

...looks like approx 60mA running - up to about 85 mA whilst firing the shutter. (including the dummy green LED, which will be a much bigger IR LED on the day.)

Five minutes later and, after hacking a USB B connector off and blobbing onto the back of the switching regulator we are looking at about 36 mA 'standing around' charge.

Thursday, 24 January 2013

timelapse fun with arduino and gopro

I do all my best work with a baby strapped to my front (it's the only way she will sleep more than 30 minutes).

This seems to work anyway... just as they said it would. I'm using these pins;

5 +5v input
6 +5v input
12 PWR button
23 battery voltage
24 battery voltage when powered, otherwise 0v
30 GND

Grounding 12 to take a photo,  monitoring the gopro battery on 23 and charging it on 5,6.

The GoPro is setup for a 10 sec timelapse in one button mode. It takes a picture when it powers up - then is powered down. The timing is off for the IR LED at present - the green LED in the photo should be on!

There are a few sites out there with instructions on building this - I've already posted links to most of them, thanks to everyone who put the time in to reverse engineer the HD bus connector, and make that information public... not to mention risk their camera grounding misc pins.

I've grounded my pin 12 with a solid state relay and i've added is a mosfet to drive my IR LED lamps. The voltage on pin23 is being logged on the SD logger shield with my temp/RH data, timestamp, and the shutter count.

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License