There is already a smart toaster that toasts the toast according to the desired browning level and not simply according to time. It even manages completely without high-tech. The only catch is that the model is 70 years old and is no longer in production. But there is a great video from Technology Connections on YouTube about it: The Antique Toaster that's Better than Yours Link: https://youtu.be/1OfxlSG6q5Y?feature=shared