[Thanks to -adrian- for submitting this project!]
Based off a modified version of the NXT shoot bot, the automatic tortoise feeder has three main components: a top feeding food hopper with a motor operated paddle that dispenses food, a color sensor for line following, and a reverse mounted touch sensor which acts as like a pull trigger. The touch sensor has a colored ball mounted in it which entices the tortoises to bite at it. Once that happens the robot dispenses the food, and then executes the line following program for several seconds and stops. At first the tortoises would just bite at it because it was brightly colored but I believe after only a few gos they’ve figured out now that pulling out it gives food which is a pretty impressive feat of reptile intelligence as far as I can tell.
What inspired you to build this robot?
I found out about NXT after watching a video sent around at work of the cubestormer robot and thought immediately it would be fun to do a robot that could interact with our two pet redfoot tortoises. Reptiles aren’t particularly trainable animals though ours are very food motivated so a robotic feeder seemed like a fun project to try. Fortunately tortoises are relatively slow moving and benign so building something to interact with them wasn’t that difficult. I also hadn’t seen any examples of NXT robots interacting with animals (though I think a friend of mine used the remote control shootbot to terrorize his cats?)
How long did it take you to make this?
Hard to say as I started and stopped several times? The programming took about a day once I went through the ROBOTC tutorials from Carnegie Mellon. I almost gave up initially trying to program it with the included NXT-G software and left the project alone until I found out about ROBOTC The construction maybe a week or two? I tried a few different designs before the current one that all had various problems. It took a while to figure out a way to mount the touch sensor in a way that would allow a tortoise to trigger it.
What are your future plans with the robot?
I’d like to try a modified mechanism for dispensing the food. The vertical mounted hopper and the irregular size of tortoise pellets makes the amount dispensed each time really difficult to control. My current idea is to try mounting the dispenser horizontally and use either one of the rubber treads or maybe a track from a lego technic set to dispense the foot more like a conveyor belt. Also might try a different way to move the robot around than using a line follow, possibly the distance sensor and some simple wall avoidance?