DIY IoT Fan (opens in new tab)

For just turning something on or off I've been happy with the "IoT Relay" from Digital Loggers [1][2][3]. It is essentially a power strip with 4 outlets and a control connection. The control connection can take either a DC signal from 3-60 V or an AC signal from 12-120 V.

One of the outlets is always on, and the other three are controlled by the control signal. Two of those are normally off and turn on when the control signal is present, and the third is normally on and turns off when the control signal is present.

I'm using it to control a space heater with a Raspberry Pi. The GPIO pins on most microcontrollers commonly used in DIY projects will work directly to control the relay.

[1] https://dlidirect.com/products/iot-power-relay

[2] https://www.sparkfun.com/products/14236

[3] https://www.amazon.com/Iot-Relay-Enclosed-High-Power-Raspber...

The issue here is that these fancy tower fans don't have a mechanical on/off switch. So just switching the mains voltage does exactly crap.

...well not crap, mine beeps a few times when the power turns on =)

The ESP32 fiddling is required to fake button presses on the touch sensitive buttons to make it actually start.

He's not playing with mains voltage (except to wire in the USB power supply) - the button's he's "pressing" with his relay are part of a low voltage control circuit.

But that just gives you on/off controls and maybe energy consumption, doesn't it? It won't let you play with the fan speed, which is probably something I'd want first and foremost.

I've used some TP-Link's equivalent up until the point when TP-Link decided to effectively brick it for me by disallowing control via local network because "security". I'm very concerned about someone on my WiFi turning on my kettle and boiling me some water. :)

OP uses an off the shelf USB 'wall wart' for power, everything else is <= the 5v that that provides. It's not really any more involved/risky/'playing with large voltages' than say changing the plug on a power cable, or using one of the terminal-block-style Sonoff devices.

220V are not large voltages. It's within capabilities of a properly taught highschooler to make sound circuits for mains.

It's when you get above 400V+, then the physics of electricity gets tricky.

> The pinout of that ESP32 board says 3.3V but the author feeds 5V into it.

He is using a dev-board with a USB jack and an integrated step-down converter. The ESP32 is not 5V tolerant at all, the pinout diagram is for the pads on the ESP32 module, not the whole board.

It does still need to be flashed. ESP32 are blank on arrival

I installed an IoT IR blaster, since our air conditioners and ceiling lights all have IR remotes. Works fine, and if it stops working it doesn't matter since we didn't actually replace anything and lose any existing functionality.

A neat trick: there is almost always enough AC on the neutral, even when the line is off to run some very low power MCU, or even do some LED blinks.

I was wondering the same - I re-read it a couple of times and he only seems to be concerned with turning it on and off. I can see where speed would also be useful and I'm sure it's just a matter of using more relays. State is another matter - but it looks like it does have a least a few LEDs that are on when it's working - a voltage probe across one of those LEDs or another similar point should be pretty easy without having to get near mains voltage.

Automation - for the vast majority of people - isn't so much about having something "on the internet" (like a free roaming chicken?) but to be able to control it intelligently. For example when I set the alarm to leave my house I have a routine that kills any lights in rooms that might be left on, adjust the thermostats on my HVAC, kills all the ceiling fans, etc.

Conversely when I'm heading home I can remotely let my automation know so that it sets the recovery temperature on my thermostats and resumes the ceiling fans to help circulate things with the HVAC system. If I had a room without a ceiling fan but could still benefit from circulation this would be a nice solution along the same lines.

Combine systems like the above with occupancy sensors and zoning and energy savings are significant enough you notice them in your power bill.

And all of that runs on a box in my living room - cloud is for remote access only; I loathe cloud only automation systems :p