Controlling single stepper via blutooth

Projects Programming
2

You are getting SoftwareSerial mixed up with Serial (HardwareSerial) in this

SoftwareSerial portOne(0, 1);

Serial uses pins 0 and 1. Use another pair of pins for SoftwareSerial and connect them to your Bluetooth device. Then, rather than

if(Serial.available()) {
    c = Serial.read();

you would have

if(portone.available()) {
    c = portonel.read();

Of course you might think that portone is no longer an appropriate name for the SoftwareSerial instance.

...R
Serial Input Basics