Quantity   Component name
1 × USB power bank Single cell version
1 × Ultrasonic distance sensor HY-SRF05
2 × 5v Stepper motor 28BYJ-48
2 × Stepper drive ULN2003
1 × Plenty of duopoint cable
1 × Raspberry pi A+ or Zero
4 × M3 bolts
4 × M3 nuts