Raspberry Pi:

IR remote for devices around the house: https://www.stavros.io/posts/how-turn-your-raspberry-pi-infr...

RF remote for more devices: https://www.stavros.io/posts/how-remote-control-rf-devices-r...

Home server for controlling various things around the house (farther down)

ESP8266:

A rotary mobile phone: https://www.stavros.io/series/irotary/

A button that orders food when pressed (Amazon-dash-like): https://www.stavros.io/posts/emergency-food-button/

Sensor board for sensing things in all the rooms of the house: https://www.stavros.io/posts/building-cheap-home-sensorcontr...

The above ties in with the Raspberry Pi farther up.

A LED strip controller: https://www.stavros.io/posts/wifi-enabled-rgb-led-strip-cont...

A toy bus with an OLED screen that shows which bus is passing by next (no post yet).

A self-driving RC car (no post yet).

A perfume sprayer that sprays perfume with an API (no post ever).

Arduino:

Nothing, the ESP8266 is better.

And these are just random ideas I got, you can do way more if you have a specific need for them.

Oh yeah, that's a great use case as well. Kodi is fantastic.

+1 for using Raspberry Pi for home automation.

I'm just getting into electronics but have found the Pi indispensable for this purpose: without much effort, I now have Pi Zero running Homebridge with plugins and hardware to control an AC power outlet switch, ambient temperature and humidity sensors, three contact sensors, and another Raspberry Pi 3 also running Homebridge with a light sensor, fan speed controller (PWM) / tachometer, motion detector, and camera.

What's great about the Raspberry Pi is it is a complete computer system, so it can run the Homebridge stack (Node.js, mDNS, etc.) for bridging your custom home automation devices (via GPIO) to the rest of your IoT system (I wrote up my experiences here if anyone is interested: https://medium.com/@rxseger/home-automation-with-raspberry-p... Home automation with Raspberry Pi + Homebridge).

However, having a full OS is probably overkill for most home automation sensors/devices, I'm looking into getting an ESP8266 or other low-power wireless microcontroller next as I continue to build out my automation to other parts of the home. An ESP8266 may be better than e.g. a Pi Zero for many of these use cases, having built-in Wi-Fi support versus an add-on USB Wi-Fi adapter. I also want to put an MSP430 to work on home automation, but need to figure out the wireless story. Instead of a heavyweight Wi-Fi stack, probably a lightweight low-data rate protocol on an unlicensed sub-1 GHz or ISM band, bridging the slower RF connection to the rest of your Wi-Fi or Ethernet network (ala ZigBee/802.15.4 and the Philips Hue bridge).

The Wemos D1 Mini (~$5) looks really nice for an ESP8266 board. I went with a NodeMcu on Aliexpress (~$3), hopefully it works well once it arrives, but at these prices not much to lose, and you can buy many for multiple projects: a computer in every room?! Exciting times, more and more companies are developing expensive home automation products to build an ultimate "smart home", but with the explosion of inexpensive single-board computers/microcontrollers for electronics hobbyists there has never been a better time to get into DIY home automation.

The D1 mini definitely is nice, I have a dozen of them running all over the house, controlling the lights, monitoring CO2, temp, humidity, power/gas/water usage the works. Do get the feeling that they might start congesting my router, but have a pi home server in the works to prevent that.

I wish there was something ESP8266 like with Ethernet, ideally even with PoE. WiFi is ok, but since I need a cable for power anyways it could carry the data just as well...

(and WLAN spectrum is quite cramped here, and part of me wants to isolate everything into nice separate networks, just to be sure)

> "I wish there was something ESP8266 like with Ethernet"

Perhaps you'll find this useful:

http://hackaday.com/2016/04/01/ethernet-controller-discovere...

You can also do real Ethernet with a teensy: https://www.pjrc.com/teensy/td_libs_Ethernet.html

Thanks for that, I like the compactness of the Teensy solution. If we're going with shields it's probably worth mentioning that the Arduino also has one:

https://www.arduino.cc/en/Main/ArduinoEthernetShield

Interesting concept, even if a bit too hacky, thanks for the link! (and probably possible with all kinds of fast-ish systems with DMA)

I'd say the Teensy is in the Arduino++ camp there. It uses the same libraries, etc, just has more power processing, a pretty nice price, and some interface bits and pieces that are very nice, like being able to act as a usb device and host. A lot of hardware, I'd argue is better to be treated as a library -- there are libraries and hardware that have definite feature sets, some of which overlap, that allows you to choose the best tool for the job.

The ESP8266/Wemos can run Arduino too. Over the summer I built a wifi clock, but couldn't get any of the native LCD libraries for the ESP to work. I flashed Arduino and used the LiquidCrystal library, initially just to make sure I had wired stuff up correctly. But then it worked, and I decided to stick with it :)

Best feature on the Teensy IMO is usb native, so you can do stuff like emulate a USB keyboard or mouse. Many DIY keyboard projects use them as the brains. https://www.pjrc.com/teensy/projects.html has more ideas. Also works great for larger Ambilight displays than Arduino can handle.

Did you finish that ESP8266-based garage door opener? Why did you choose wifi for that?

I used a Wemos D1 Mini and a relay shield for this. Soldered leads to the physical button inside my garage and connected that to the relay. Toggling the relay on then off is now equivalent to pressing the button. There is an outlet next to the garage door button, so the project is powered via a USB plug and a short micro USB cable. It runs a firmware that emulates Belmont WeMo (which is really UPnP) so my Amazon Echo recognizes it. Viola! A voice controlled garage door.

I have yet to install the reed switch on the door so the thing is smart enough to actually open and close and not just emulate button pressses.

I don't trust this setup to control mains power (look up Sonoff devices for that), but the garage opener is 12 V so I feel ok about not setting things on fire with that.

I made a similar thing, and I chose wifi because the garage was simply too far for wires. It's a simple build with a relay over wifi.

Why would you use wifi rather than radio? encryption?

For me: because it requires the least amount of hardware and also works with Amazon Echo for voice control. With a different type of radio, if you still need it on the internet, you have to somehow bridge it, which means more hardware.

Yes, and reliability. TCP gives you a lot of nice things.