Hi, I have an idea to build an automatic hamster feeder using a simple servo motor, an RTC DS3231 module and a Arduino MEGA2560.
Reason to use these components is because I already have them from previous projects.
The idea is basically once everyday, the servo will shift to open a gap for the hamster feed to drop into a bowl and then shift back to close it. Other than this, I want to set my Arduino board to sleep so that I can save power. The RTC module will set an alarm to trigger an interrupt and wake my Arduino board again at the next feeding day at the same time.
My concern is the power consumption because I require this feeder to run on a battery/power bank for at least 2-3 weeks as my family is going overseas. Is my project feasible?
EDIT: Apologies if I made it sound like I'm gonna leave my hamster alone to fend for itself for 3 weeks, I do have someone who will be taking care of it however this project was an idea to make it easier for him so that this favour would not be too disruptive.
Be aware that putting the processor on the Mega board in sleep mode will not help against the other onboard components (led, serial-to-usb converter etc) consuming power. So you have to strip your board if you really need low power consumption; together they will possibly use more than the ATmega2560 processor.
You will also need to do long term testing to prove that it works reliably; you don't want to come home from your holiday to find that your hamster(s) have died because your system failed due to some condition.
What about water supply for the hamsters. I think that they might be able to go quite long without food but not without water.
For the rest it sounds feasible
Personal perspective:
It's one thing to have pets and leave them alone for a couple of hours. It's another thing to leave them alone for 3 weeks; arrange a babysitter.
Why does going on vacation mean you have no source of dependable electricity?
Leaving the hamster in the manner you plan is insane, even if you were an expert programmer and highly accomplished at mechanical designs.
I don't even want to list all the things that could go wrong.
I will say my personal cat feeder (food auger on RTC schedule) worked OK, and the one we bought for $$$ was better, but both managed to fail in unanticipated ways, and in predictable ways.
Never more than a few hours of unhappy hungry cat.
Mechanically, you ignored the problem of trying to close the gap while the food is flowing. Please test how this will work so you will see the problem. Opening is easy, but closing against a flow of solid food will be really hard!
I think is perfectly feasible,
Reliability concerns can be addresses building two devices, like an airliner, you cannot do a single engine device and find, as others remarked, your hamsters death.
I would not use servo "closing" for the same reason that has been mentioned in a previous answer.
A clever design is to distribute with a vertical recipient, finsh the bottom part with a conical device. below the device put a disk of vertical axis driven by a little 300 rpm motor.
Install for blades over the disk to distribute your pellets by centrigugal force.
Play with motor run time, gap between the lower border of the cone and the upper line of the blades, and the size of the pellets to get the volume you need.
With a small battery of 12 V @ 7Ah and a panel charging energy should be good, unless you have very little sun time in your place.
It's not hard to make a water pan with a gallon jug of water inverted with the mouth spaced 1/4 inch off the bottom of the pan. When the water is consumed below the mouth, more water will "glub glub" out of the jug until the water level is above the jug mouth. Like an old time water pan for chickens made from a quart mason jar inverted and sitting in a pickle jar lid with a dent in it to let the water "glub glub" out.
Look at how humming bird feeders work.
As with a lot of projects the mechanics of how it will work need looking at first and building .
The simplest methods seem to involve uncovering food rather than trying to move it around .
Have a look at how commercial ( eg cat ) feeder s operate for ideas .
