The Amazing $1 Microcontroller (2017)
My favorite is the ATTINY 85. It's so cheap and yet, it can do almost most of the things you can do an Arduino. And yes, you can program it using the Arduino IDE as well.Last year, I started out to digitalize my entire house with these tiny ATTINY 85 chips and with some nrF wireless chips. It has worked really well for me and I'm able to control and monitor any power port in my house as well as my mains.The overall setup still costed less than a Nest, yet, vastly more powerful. Of course, the downside is you need to write code, have a running server to control it on the cloud. But, no problem for me as I'm a (Google Cloud) consultant and this is what I do for a living.I use Google Cloud's IAP with AppEngine (I may switch to cloud run now, since it's cheaper tho) and I have a private REST server running that I can access from my own Android app.The whole thing took me a year to finish, but that's because I worked on it maybe once or twice a week in the weekends and didn't focus on it much.But, my effort has paid off and it's amazing to me that what is possible with just a dollar investment.