Old Tablet + Laptop Webcam + Broken Phone Speaker → AI Doorbell That Recognizes Faces and Talks Back

Energy needed to make	[e.g., 150 MJ per unit]
Critical earth materials	[e.g., 5g cobalt, 2g lithium]
Energy needed to disassemble	[e.g., 10 kWh for full dismantle]
Energy to procure materials	[e.g., 50 MJ for CRMs procurement]
Total supply chain emissions

Mount cracked tablet outside as screen.

Use laptop webcam + Coral USB accelerator ($60).

Run Frigate or Home Assistant locally.

Add phone vibration motor as ringer, phone speaker for voice.

Greets delivery drivers by name, scares strangers with “I’m calling the police.”

Total new parts cost: under $70.

Beats Ring Pro performance and no subscription.

Your trash drawer is a hardware store that’s already paid for. Start building tonight.