UPDATE! – 16/08/2020
(If you’ve not seen the original post, you can read it HERE)
So, it turns out my first design was actually…. pants. It exhibited several issues right from the get go which I’d hoped would sort of see themselves right, turned out not to be the case. The flap either needed to be held in place (therefore using the motor constantly and draining the batteries and generally putting a bit too much stress on the whole system) or off, which then means you had to be extremely careful with the weight of the seed else it would just dump everything all over the place. It did this a lot.
I actually want to set this up outside, and for a considerable period of time. I looked around online for ‘automatic bird feeders’ for inspiration as to how to build a reliable mechanism. You’ll find a lot of farming type equipment, but very little in the way of wild bird feeders.
The mechanism, it has to be reliable and be able to deliver a set amount of seed each time. I decided the easiest / most straightforward option was either a water wheel type set up or an Archimedes screw to deliver the seed.
I went with a wheel design first off, I used OpenScad to design a cog-type wheel then cut three of them and sandwiched it all between two plates.
The stepper motor and the Pi etc are now all mounted behind the main board. I then built a box with a cut out for the seed to drop from, I also made sure the spacing was such that the seed can’t get caught anywhere and jam the mechanism.
I built a front window using an old CD case. From the experiments I’ve seen, the birds need to be able to actually see the prize!
I then build a rear box to cover all the electronics, and gave it some serious weather-proofing with a proper shed roof and many, many coats of lacquer.
I now feel this will stand up to the elements – and hopefully visitors! I’ve also managed to complete the OpenCV motion detection with the Raspberry Pi camera. I was going to run it all off the same Pi, and it was set originally up this way. I then had a DOH! moment when I realised the camera cable is 50cm long…. and the focal length of the Pi camera is a minimum of 1m
I’ve therefore offloaded this work to another Pi set up. This is motion activated and records a three minute video with a timestamp when something steps in front of the camera. The birds tend to visit the garden in regular waves so it’ll be interesting so see exactly how regular their visits are.
This is now all being moved to the shed roof and I’m looking forward to seeing what our feathered friends make of the whole affair!
Stay tuned for updates and training progress.
Until next time…