Quantity   Component name
1 × ESP32-S3 N16R8 dev board, dual USB-C Two USB-C ports (COM + native USB). Bridge the USB-OTG pad.
1 × USB-C telephone handset with USB audio chip Retro handset for mobile phones; tested AB17X (001f:0b23)
4 × 60 mm arcade button with 12 V lamp One per person, 1 to 4. Lamp glows at 3.3 V, no resistor
16 × Female Dupont jumper wire Four per button: two for the switch, two for the lamp
1 × USB-C phone charger Powers the board through the COM port
1 × USB-C data cable For flashing, then for the charger
1 × Enclosure Shoebox, or a laser-cut plywood box
1 × Twilio account + one US voice number About $2 to $3 a month to run