For my first Arduino project I'm looking into making an animatronic robot eye. I'm thinking the eye will be made of a halves ping pong ball initially. This is just a personal project I'm interested in. Eventually I'd like to add an LED and maybe face recognition but for now just random movements would be really cool.
I'm confident in my ability to write a sketch that can move 2 servo motors to a random position between random time intervals to mimic eye movements, my questions have more to do with the wiring and the necessary components!
I currently have an Arduino UNO and a starter kit for it. Lots of capacitors, resisters, etc. etc. My specific questions are as follows, but please feel free to leave generic advice you think would be helpful!
- What servo motors can you recommend?
- I have soldered before but never on my own. Any helpful hints?
- What parts will I need and how should I wire them?
Controlling a servo from an Arduino is relatively easy, because the servo takes care of most of the work involved.
I suggest you use any hobby servo you can find locally within your budget. Even a small cheap servo should have no problem with the sort of speeds and loads you'd be dealing with here.
You will need an external power supply for the servos - a 6V rechargeable battery pack would do the job nicely. Connect the negative terminal of the battery pack to the ground of the Arduino. Connect the red and black wire from each servo to the battery positive and negative. Connect the white (signal) wire of the servo to a digital pin on the Arduino. Use the Servo library in your sketch and create a Servo object for each servo, and attach it to the corresponding pin. You can then move the servo to a specified position using the write() method.
As long as your power supply can supply them all it's easy to control multiple servos (one servo per available I/O pin) so you can easily include more complex animation mechanisms if you want.
Bear in mind that servos tend to be quite noisy, and cheap servos can sometimes suffer from jitter (they will rattle back and forth a little when you command then to stay still) but give it a try and you'll soon get the idea.
Attached is a diagram that I found on this forum on how to wire up a servo.
Best of luck!
Also, I have attached a file that I found on Instructables on how to mount the servo to the eye.
Thanks for all the tips! I have done some work with servo motors in class before and have been told to use capacitors with servo motors. Is there a need to wire any up along with the 6V power supply or are they not necessary with such low voltage?
I have never used a capacitor when using servos and all my servos work correctly.