Arduino and a hacked servo

So I recently hacked a 5V hi tec HS-322HD servo to produce continuous rotation. I removed the mechanical stop and replaced the pot with a voltage divider.

When hooked up to the arduino, the servo.write(180); command will give me continuous clockwise rotation. Unfortunately, so will every other servo.write(); I use. The problem with this being that I need continuous rotation in either direction. I’ve read that this is possible, but can’t find any documentation using the Arduino to achieve this.

Does anyone know of an easy method to achieve clockwise and counterclockwise movement using the arduino and a hacked servo?

(Note: I’m doing this using the ServoTimer1 library)


Are you sure the voltage divider is connected ok?. You may want to try temporarily replacing it with a pot (perhaps the one you removed) and see if you can adjust the value so the motor stops when you drive the servo with a signal that is midway between maximum and minimum, i.e. servoWrite(90) .

I agree with mem You really want a small variable pot to trim the servo with a mid value. Ive done this in the past on a basic stamp robot I built. Hard wiring the resistor just wasnt reliable and with cheap servos you may have to re trim later anyway.


i’ve still got the pot on hand…

I’ll try this tonight or tomorrow morning. Thanks guys.

I replaced the divider with a pot. It solved the problem wonderfully. I just tucked the pot in the servo case so it's shaft didn't protrude into the gear assembly. Doing so allowed for the full rotation without changing the pot.

Thanks, guys.