Automated dog feeder

[ROB K-9]

Hi everyone,
I'm new to this forum and to the world of electronics.
I want to make an automated dog feeder using a screw conveyor system. Ill be using a 12v 5 rpm motor to turn the screw. I have 2 questions:
1. How would i connect it to a power source?
2. What could i use to programme it?
Many thanks
Rob

 

[KD494]

Welcome,

I'm actually going to start with question two first. If you're looking for something simple to easily learn to program, Arduino is always a good starting point. Unless you're looking to add some network connectivity or anything super fancy anything more feels like overkill.

As far as connecting the motor to the power source you want to make sure that you're not directly connecting the motor to the Arduinos GPIO in any way. I believe the maximum current a pin can source or sink is about 20mA, less for most other platforms. The easiest way to handle this would be to use a pre built motor controller or shield if you do go with Arduino.

However if you're looking to learn a bit more and do some soldering yourself its not too hard to build something up yourself. If the motor only needs to spin one direction you can do this with a single transistor and resistor as shown **broken link removed** or any number of tutorials.

If you need bidirectional motion I would look into the concept of an H-bridge. This is all assuming that your motor is a simple DC motor with just two connections.

Hope some of this helps.

 

[ard]

I think the easiest would be to use a mains timer like this **broken link removed**

Its quite versatile, gives a number of program cycles per day, or day of the week.

I have used quite a few of these, and they are quite reliable.

At the output of the timer, just connect your 12 volt power supply that drives the motor.

Note that this is a 240 volt version, in case you are in a 120 volt country. Also, they come in 2 versions; dry contacts (no mains on the output, just the relay contacts bought out), and switched mains output.

Regards.

 

[ROB K-9]

Hello again,
Thanks for the input. My initial plan of using a conventionalmotor turning a screw has developed into possibly using a stepper motor so i'm able to control how much rotation i need. If i go down this route could anyone suggest what items i need? As already mentioned Arduinos are good but i have no idea which one to get and which shield to use.
Any help would be greatly appreciated
Cheers
Rob