code to force a gentle servo power up So I am new to the board and looking for a source to answer an Arduino servo project's rough power up.  The project uses a pair of servos operating together to swing a small door.  I have been working with intro level sketches over the last few weeks. I have powered and re-powered my Arduino Uno several times with different codes and each time the unit is powered the two servo motors move to their last position at what appears to be full speed resulting in a rather jerky and jumpy power up.

What can you suggest in the code that would force the servo motors to gently move toward their new code starting position?  Like a 'warm up cycle'.
You cannot do that with ordinary servos. This is because of the way the
communication protocol is built: the only thing a servo understands is a
command which in effect means “go to that position as fast as you can”.
You can achieve smooth movements by updating the requested position (the
so called “set point”) many times by tiny steps, but you still have the
problem at startup.

I see two possible solutions to your problem:


Make sure you know the position at which the servo was left when you
powered down your Arduino. You can either arrange to leave it always
at the same position, or you can store the last position in EEPROM
before powering down. Then, at startup, you initialize the servo with
that last known set point.
Use a special type of servo known as a feedback
servo,
or convert a regular
servo to
get a feedback. A feedback servo is a type of servo that tells you
its actual position, so you can arrange for the initial set point to
match that position.