Newbie - Frigelli L16P + LAC "Un rest movement", what is it I'm missing here?

Other Hardware Robotics
1

Hi,

I have a simple project using Arduino Uno, L16-P Miniature Linear Actuator with Feedback and the Firgelli Linear Actuator Control Board (LAC), I connected the Arduino to the LAC using pin -9 to "RC / Hobby Servo input signal" as in the image below:

the code is very simple:

#include <Servo.h> 


#define PIN_SERVO 	(9)
#define START_POSITION 	(20)
#define END_POSITION 	(35)

Servo myServo;

void setup() {
   // set servo
   myServo.attach(PIN_SERVO);
   
   //open serial window for log
   Serial.begin(9600);
}

void loop() 
{
		
	SetStrokePerc(START_POSITION);
	Serial.println("START_POSITION");
	delay(5000);

	SetStrokePerc(END_POSITION);
	Serial.println("END_POSITION");
	delay(5000);
	
}

void SetStrokePerc(float strokePercentage)
{
  if ( strokePercentage >= 1.0 && strokePercentage <= 99.0 )
  {
    int usec = 1000 + strokePercentage * ( 2000 - 1000 ) / 100.0 ;
    myServo.writeMicroseconds( usec );
  }
}

The Problem: when running the project the actuator stroke doesn't fully stop at the START/END points but keeps on moving a millimeter in and out all the time as shown in this clip

What is it I'm missing here??

Thank you all in advance,
Best,
Ram

2

for anyone else who encounters this the problem is the LAC is trying to drive the actuator to a point the actuator is not able to achieve so it is hunting back and forth, it can be eliminated by lowering the accuracy pot on the LAC just a hair and then power cycling the LAC board:

the end result.

Best,
Ram