I want to build a wattmeter based on a Pi Zero (to reduce costs in the final version, maybe I can use a Pi3 to develop it. Can you tell me if this is possible, based on what I need to do? I need to measure power in realtime used by a computer. My idea is to insert the Pi based power meter in between the power cable of the computer and the computer itself. For what I saw, I understand that I need the Pi, a Voltage Divider (I ignore exactly which one or where to buy one) and... anything more? The idea is to power the metering device from a free USB port in the computer and I have to think how to access the data stored in the Pi (I have to upload it every minute to a database).
Can you be kind enough to explain this to an ignorant like me?