TMC2130 driver debugging

simple_test.ino

/**
 * Author Teemu Mäntykallio
 * Initializes the library and turns the motor in alternating directions.
*/

#define EN_PIN    48  // Nano v3:	16 Mega:	38	//enable (CFG6)
#define DIR_PIN   16  //			19			55	//direction
#define STEP_PIN  17  //			18			54	//step
#define CS_PIN    31  //			17			64	//chip select
#define MOSI_PIN  51
#define MISO_PIN 50
#define SCK_PIN  52

bool dir = true;
#define TMC2130DEBUG
#include <TMC2130Stepper.h>
// Soft SPI
TMC2130Stepper driver = TMC2130Stepper(EN_PIN, DIR_PIN, STEP_PIN, CS_PIN, MOSI_PIN, MISO_PIN, SCK_PIN);
// Hard SPI
//TMC2130Stepper driver = TMC2130Stepper(EN_PIN, DIR_PIN, STEP_PIN, CS_PIN);
void setup() {
	Serial.begin(9600);
	while(!Serial);
	Serial.println("Start...");
	driver.begin(); 			// Initiate pins and registeries
	driver.rms_current(600); 	// Set stepper current to 600mA. The command is the same as command TMC2130.setCurrent(600, 0.11, 0.5);
  driver.microsteps(16);
	driver.stealthChop(1); 	// Enable extremely quiet stepping
	
	digitalWrite(EN_PIN, LOW);

	Serial.print("DRV_STATUS=0b");
	Serial.println(driver.DRV_STATUS(), BIN);
}
bool isKilled = false;
void loop() {
  if(driver.checkOT()){
    if(!isKilled){
      Serial.print("Overheat flag triggered: ");
      Serial.println(driver.getOTPW(),DEC);
      driver.TPOWERDOWN();
      isKilled = true;
      Serial.println("Program stopped");
    }else{
      delay(1000);
    }
  }else{
  	digitalWrite(STEP_PIN, HIGH);
  	delayMicroseconds(10);
  	digitalWrite(STEP_PIN, LOW);
  	delayMicroseconds(10);
  	uint32_t ms = millis();
  	static uint32_t last_time = 0;
  	if ((ms - last_time) > 2000) {
  		if (dir) {
  			Serial.println("Dir -> 0");
  			driver.shaft_dir(0);
  		} else {
  			Serial.println("Dir -> 1");
  			driver.shaft_dir(1);
  		}
      Serial.print("OverTemperature: ");Serial.print(driver.getOTPW(),DEC);
      Serial.print(" MSTEP: ");Serial.print(driver.microsteps(),DEC);
      Serial.print(" DIR: ");Serial.println(driver.dir(),DEC);
  		dir = !dir;
  		last_time = ms;
  	}
  }
}