I am an engineer. My nine-year-old is very underserved on learning this stuff at school -- I'm teaching to him on the weekends.

I bought two things.

An Arduino kit (hundreds of parts to make dozens of projects)

A book from Make Magazine

It covers all the basic electronic theory to start making programmable hardware.

Project #2 is very doable. If you go through the book, learn the theory, it's just

• sensing what a scale is doing
• checking the time

I bet lots of people have written projects for it.

SO MANY THINGIES https://www.amazon.com/EL-KIT-001-Project-Complete-Starter-Tutorial/dp/B01CZTLHGE

(I apologise in advance for the enabling)