Hi, I have been looking at controllers and it seems that the Arduino with a motor shield can only control 2 servos or 4 dc motors (assumption please let me know if I am mistaken). I https://reprap.org/forum/read.php?13,14986,14986#msg-14986 Sun, 13 Sep 2026 10:09:04 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?13,14986,14995#msg-14995 https://reprap.org/forum/read.php?13,14986,14995#msg-14995 -------------------------------------------------------
> I have been looking at controllers and it seems
> that the Arduino with a motor shield can only
> control 2 servos or 4 dc motors (assumption please
> let me know if I am mistaken).

The limitations you mention would be limitations of the "Motor Shield" you are looking at. The Arduino has 13 digital I/O pins and 6 more pins that can be used as either analog inputs or digital I/O pins.

Since an RC servo just needs one digital output (pulse width control) to control its position you could run 19 RC servos (and nothing else) off a single Arduino.

The Arduino firmware provides for PWM outputs on 6 of the digital I/O pins. Using external H-bridge circuits you could use those 6 pins along with an additional 6 digital I/O pins for 'direction' signals to drive six speed-controlled bi-directional DC motors. If you don't need reversible motors you can use just the 6 PWM outputs and driver transistors to drive 6 DC motors.

You have 19 digital pins of which 6 provide PWM outputs. You need one digital pin per RC servo, one PWM output per unidirectional DC motor, one PWM output and one digital pin per bi-directional DC motor and one pin per logic input (or up to 6 analog inputs). Stepper motor controllers usually use two digital output pins (step and direction).

You can also do your own software PWM output on any digital I/O pin. That would allow you to run 19 uni-directional DC motors with a single Arduino.

The game controller you point to provides 16 switch inputs and 16 PWM outputs suitable for LED's and very small (1/2 amp) motors. It also requires a PC to control it via USB. I don't think you could run a Darwin with it because it has not stepper motor controls.]]> JohnWasser Controllers Mon, 28 Jul 2008 10:13:23 -0400 https://reprap.org/forum/read.php?13,14986,14986#msg-14986 https://reprap.org/forum/read.php?13,14986,14986#msg-14986
I have been looking at controllers and it seems that the Arduino with a motor shield can only control 2 servos or 4 dc motors (assumption please let me know if I am mistaken). I]]> Anonymous User Controllers Mon, 28 Jul 2008 06:26:54 -0400