ARDUINO: Poorman Unipolar Stepper Motor Driver Circuit

I am not an expert in electronic, just do a little try to make some application to drive a unipolar stepper motor ( ex. unused EPSON LQ-1050+ Printer).

Hacking an unused old epson lq-1050+, break the chasing :) to get some part to do this trial, I got :

1. D1888 (Darlington transistor)                                4 pcs
2. EM-110 STN 39D170 Unipolar Stepper Motor   1 unit
3. Limit switch                                                                1 pcs
4. Broken board ( 2 push button switch circuit)   1 unit

Some other component from my components box  :

5. LED                                                                                3 pcs
6. 220 Ohm Resistor                                                      4 pcs
7. 103 Ohm Resistor                                                      2 pcs

And reusable circuit :

8. Arduino Uno R3
9. Power Adaptor 5V ~ 2A

This circuit is working, but I not sure this is a good circuit :) ( I just an electronic beginner ).

I create an aplication in my PC to drive this ciruit via USB, everything work as intended.