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### Topic: Control Motor frequency and amplitude (Read 347 times)previous topic - next topic

#### cooltafel

##### Nov 21, 2018, 11:11 pm
Hello all,

For a project I have to make a cradle that rocks. The controller is the Arduino which has to proces some information to actually give a PWM output signal.

I am a bit stuck with the part of moving the cradle. I know that the motor is attached to the cradle on the underside, so it makes like a sliding motion. But then the hard part comes. The motor has 4 inputs, namely frequency +, frequency -, amplitude + and amplitude -.

The motor works on 12V 0.8-1A.

I know that I have to use a transistor to switch between the Arduino and the motor circuit, because the Arduinos 5V are too low for the motor.

I have to get 2 PWM signals out of the Arduino both with approximately 1KHz frequency...
So 1 signal is for the amplitude and 1 is for the frequency for the motor.

The PWM signal of the Arduino is from 0V to 5V, the problem I occured is that when e.g. the cradle moves upward, then it only will go upwards, because the Arduino gives no negative voltage to also move downwards. Also how should I combine the amplitude with the frequency? I really have no idea...
The only thing I can imagine is that during the period time of the frequency the cradle has to go x times up and x times down.

#### Robin2

#1
##### Nov 21, 2018, 11:20 pm
The motor has 4 inputs, namely frequency +, frequency -, amplitude + and amplitude -.
Please post a link to the datasheet for the motor so we can see the technical details.

Also post a schematic for your circuit. See this  Simple Image Guide

...R
Two or three hours spent thinking and reading documentation solves most programming problems.

#### cooltafel

#2
##### Nov 25, 2018, 07:34 pm
Hello,

As it seems to be the motor is connected to an SSC-32U board, this is an servo motor driver.
This is already a big step.
Stil I don't get how to control the frequency.

There are 2 signals that are coming from the Arduino. 1 for the amplitude and 1 for the frequency.
The Servo library really easily helps to modulate the amplitude of the movement.
Only the frequency is a bit vague. Because both of those signals have a PWM of 1Khz.

#### MarkT

#3
##### Nov 25, 2018, 09:29 pm
You need to post all the information you have about the motor, photos if necessary, otherwise we are
guessing completely in the dark.
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

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