more than 12 servos

arduino duemilanove can only control up to 12 servos using the mega servo library right? what choices do i have if i need to move up to 20 servos? i dont want to buy the arduino mega board :-/




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You could use a second arduino board connected via serial or i2c to control 12 of the servos. There are some low cost boards without USB that would work as the slave in this kind of application. That would give you up to 20 servos if you ran the other 8 of your main board.

What are you using the 20 servos for? You may be able to run more servos with the MegaServo library but the refresh rate would drop and you would lose servo performance.

gota prototype this 4 legged dog like thing… each leg has 4 servos… the rest for the head and torso… so a second arduino is the way to go huh… thanks!

There is some code posted in this thread that you can run on the slave board to receive Servo commands: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1247570790/6#6

Your master Arduino could have a function like this to send the commands: void sendCommand( int servo, int value) { // send the given value to one of twelve remote servos numbered from 0 to 11 Serial.print(servo + 'a', BYTE); Serial.print(value,DEC); }

Good luck and keep us posted on how you get on.