BirdBoxPi2015: using a Picaxe controller

Looking back at my last 2 posts, I started thinking about how I might incorporate a Picaxe into the BirdBoxPi2015 controller.

Although the 8 pin Picaxe is a little more expensive than the 555 timer currently used, it does offer more flexibility.

My RaspberryPi bird box system runs from a 12Volt, 12Ahour "mobility" lead-acid battery.

RaspberryPi inputs: to poll or to interrupt?

One of the best features of the RaspberryPi is the GPIO (General Purpose Inputs & Outputs).

Reading the input levels on the GPIO is pretty easy, especially using Gordon's wiringPi library.

But you need to think carefully about how best to do this in the software for your chosen project.

BirdBoxPiCam 2014; #2b Activity Based Power Control Details

Progress has been very slow through December, due to both project related issues, and real-life getting in the way (which is actually not a bad thing).

Project issues include a cmos 555 timer with a strange fault, a damaged RaspberryPi USB socket, and discovering my choice of relay was a bad one.

Although the relay had a 1A contact rating and looked suitable for a Raspberry Pi drawing less than 500mA, this rating is for a purely resistive load. (see earlier post for relay circuit details.)

BirdBoxPiCam 2014; #2a Activity Based Power Control Details

Following on from an earlier post, I now have a prototype circuit undergoing testing.

This seems to be behaving as expected, and draws very little current when in standby.

Just to recap, this circuit will power-up my RaspberryPi when activity is detected at the entrance to a bird box (e.g. a bird or an insect breaking the beam between an infrared source and a detector).

BirdBoxPiCam 2014; #2 Activity Based Power-up & Power-down

Although the power drawn by the RaspberryPi is very low for a computer, its still significant for battery powered equipment such as my bird box monitor.

So here is an idea to reduce power consumption during periods of inactivity.

During the early weeks of the nesting season, visits by birds to garden nest boxes may be infrequent. Typically here in southern England, garden birds may start checking out nest sites during February, with more activity running into April, when nest building typically gets under way.