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?
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.
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.
shieldlist.org is very handy for figuring out conflicts between stacking shields.