Quantity   Component name
1 × Arduino Nano
1 × Rotary Encoder https://www.aliexpress.com/item/2PC-YT2004Y-Rotary-Encoder-with-Switch-EC11-Audio-Digital-Potentiometer-Handle-length-15mm-Rotary-Coding-Switch/32826453253.htm
1 × AA Battery Holder
1 × Four-digit, Seven-segment display https://www.aliexpress.com/item/0-36-Inch-0-36-4-Digit-Red-Green-Yellow-Blue-White-LED-Display-Tube-Decimal/32866984077.html
3 × 3k3 Resistors
1 × 560R Resistor
1 × 27R Resistor
1 × 20mm 8-ohm speaker
6 × Yellow LEDs
1 × BC547 Transistor Or equivalent
4 × AA Batteries