Servo misbehaving without a control signal... :(

Community General Discussions
1

hi all, I'm trying to control some servos (Turnigy TG9e) using an Arduino. I use external power for the servos (5V, 3Amp), and keep the grounds together.

the problem is that during RESET (or startup), the servos jumps fast to an out-of-range dangerous zone...

I tried adding resistors any many places (from the control pin to the ground, in between the control pin and the servo, and even between the control pin and the positive terminal) - didn't help.

I disconnected almost everything. leaving only the external power supply connected to the servo (no arduino, no control). still, the servo instead of 'staying foot', jumps to the edge (when touching its control wire by hand..).

where is the problem? how do people get around to control robots with this sudden movement during lack of control periods (during power up / boot / reset) ??

any help ?

2

Have you tried powering up

Have you tried powering up the Arduino, having it start the servo signal, and then turn on the 5V to the servo? I have heard of that helping with this scenario, but I haven’t done much experimenting with it.

3

great - how can I do it?

thanks - that sounds like it could work :slight_smile:

how can I do something like that?

4

Two toggle switches, one for
Two toggle switches, one for the Arduino and sensors, the other for the 5V powering the servo. Duane S discribes his setup for this here: https://www.robotshop.com/letsmakerobots/node/1965#comment-6139