Rev B V 1.1 PCB, improved dispenser, simplified enclosure,

A project log for Vending Machine for Birds

Simple, inexpensive bird feeder that dispenses peanuts in exchange for dropping stuff in a hole. A vending machine for clever birds.

stephen-chaseyStephen Chasey 10/29/2023 at 20:070 Comments

I offered to build a vending machine for a university student who wants to use it for a study. I had to think about optimizing for shipping, simple setup and mounting, and for reliable operation by someone not familiar with the electronics and mechanisms.

Rev B V 1.1 PCB

Finally - works as intended with no bodges! I'm so happy about this. You can find it at PCBWay here:

The Kicad files are on GitHub:

Improved Dispenser

To give the vibration platform a little slack to vibrate in and keep it from slowly rotating and tangling or pulling on wires. I cut 3 small legs into the PVC pipe slice that supports them and matching notches in the platform. This way, you don't need to manually adjust anything and it will work reliably.

Here is a short video showing the improved dispenser at work. It's quieter and faster than before.

Improved Baffle

The baffle used to be horizontal, so some peanuts would just sit there as the vending machine peanut level ran low. I used a dremel to slice a piece of PVC pipe at a slight angle so it would have a downward slope. The slight vibration that reaches the baffle from the dispenser is enough to make sure everything rolls off down to the dispenser.

Simplified enclosure

The student will use an external camera, so I didn't put a camera arm on this one. I did simplify it a bit - slightly more compact with fewer parts. The deposit sensor monitors a 45° opening instead of a vertical opening, so rain and dripping water will not pass by the sensors while objects will. Any water that does get in will drain out the bottom.

They will also be using mains power outside, so I put a plug on it with a safety box. The lower half comes off if you loosen a hose clamp so you can look inside, swap batteries or troubleshoot.


I've found that when mounting on vertical objects like railing support or fence posts, hose clamps work great.

I plan to ship this in the next few days. Will be a challenge to pack and pad to insure it arrives in the same condition it leaves in.