Checking s what's right...

I need to power 18 individual servos and at least 2 inputs (sound and distance sensor). I would alspo like to use the XBee bluetooth shield with my project as well (at a later date). I am thinking the mega will work, but I only see that it support up to 16 pwm. I am still trying to learn about arduino, but so far I am really liking what I see. I am a bit confused as to what I would need to control 18 servos and receive inputs, but I am starting to think that the arduino might not work for my idea.

My background is that I just finished up using parallax's stuff, and would like more advance projects. I already installed the arduino software and see that it resembles C as the programming language (which makes me happy), and I can use linux (and finally get out of the virtual box that I have been using for parallax). I have a design in my head, but in order to do it, I need to meet the requirements above. Is what I am asking for not going to be possible with arduino?

  • Will

Well I'm no genius at these either, but I use the mega as well. And I am running 16 outputs to drive a relay board I got off of eBay to turn on driveway lights. I also am using 2 inputs(interrupts) to detect and turn them on via a loop detector and IR detector. So to answer your question. The mega should support what you need. It does have 54 I/O pins . But I'm sure your aware of that. I too, came from the parallyx community and went to the dark side. I absolutetly love this stuff.

I looked at the board again and saw that there was 18 digital outputs (22-52), so I am assuming that I can control all of the servo's with that and use the pwm's for the I/O functions from the bluetooth, distance sensor and the sound sensor.

I need to so some research on stacking shields, I would really like to use the bluetooth shield and easyVR voice recognition shield.

On a side note, I started with Vex Robotics, then migrated to parallax. Both to me were toys compared to what I am reading about arduino. When I saw that you could actually use linux to program, I was shocked.. then I checked my iPhone and the Motorola Xoom to see if there were wireless remotes to incorporate with my projects, and I won the freakin lottery!!! I recently just built a CNC table in my garage so that I could start cutting some custom parts, but got caught up with cutting out dinosaur puzzles for my son. Anyways, enough of my rambling... I am about to hit the purchase button on amazon and get started!

Thanks for the help.

  • Will

The Servo Library will enable 12 servos on the basic Arduino boards and 48 on the Mega boards. The library implements PWM in software; by default the Mega is only capable of PWM on pins 2 to 13 and 44 to 46. is very handy for figuring out conflicts between stacking shields.