I use firmware from lastest release 2.4.0 from https://github.com/euphy/polargraphcontroller/releases and polargraph_server_polarshield.ino is used.

Changes for RAMPS14 ;
#ifndef MOTHERBOARD
//#define MOTHERBOARD POLARSHIELD
#define MOTHERBOARD RAMPS14
//#define MOTHERBOARD TFTSHIELD
#endif

//#define USE_LCD

Check the pins for motors from configuration.ino.

Steppers is not working. I check my hardware configuration with the code below. Microstepping jumpers in ramps removed.

#include <AccelStepper.h>

// Define some steppers and the pins the will use
AccelStepper stepper1(1, 60,61);
AccelStepper stepper2(1, 46,48);
void setup()
{

stepper1.setEnablePin(56);
stepper1.setPinsInverted(false, false, true); //invert logic of enable pin
stepper1.enableOutputs();
stepper1.setMaxSpeed(600.0);
stepper1.setAcceleration(2000.0);
stepper1.moveTo(1000000);

stepper2.setEnablePin(62);
stepper2.setPinsInverted(false, false, true); //invert logic of enable pin
stepper2.enableOutputs();
stepper2.setMaxSpeed(600.0);
stepper2.setAcceleration(2000.0);
stepper2.moveTo(1000000);
}

void loop()
{
stepper1.run();
stepper2.run();
}

With these codes steppers works nicely.

Serial connection on controller software succeed.
Starting Queue succeed.
Pen lift and down setted.
Test Lift Range succeed.
Move Pen to Point is not working.

Anyone have any idea ?