 		}
 	}
 	if (running) {
-		digitalWrite(STEP_PIN, HIGH);
+		digitalWrite(pinStep, HIGH);
 		delayMicroseconds(speed);
-		digitalWrite(STEP_PIN, LOW);
+		digitalWrite(pinStep, LOW);
 		delayMicroseconds(speed);
 	}
 }

float hold_x = 0.5;

#include <TMC2130Stepper.h>
TMC2130Stepper myStepper = TMC2130Stepper(EN_PIN, DIR_PIN, STEP_PIN, CS_PIN);

void serialTuple(String cmd, int arg) {
	Serial.print("Received command: ");

		if (cmd == "run") {
			serialTuple("run", arg);
			running = arg;
		}
		else if (cmd == "speed") {
			serialTuple("speed", arg);
