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DIY IoT Fan

mulliken.net

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Re: DIY IoT Fan

#21

Post by baybal2 »

stavros wrote: post #12

This is a nice hack, but I'm always very wary of playing with large voltages because it's too easy for things to go wrong. Instead, for controlling mains devices, I recommend a Sonoff S20: https://esphome.io/devices/sonoff_s20.html I usually flash ESPurna onto it (Tasmota and ESPhome are also good choices), it's very easy to do and it's extremely reliable and hopefully has a lower chance of fire than anything I'd mak…

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.

Re: DIY IoT Fan

#22

Post by adolph »

baybal2 wrote: post #21
stavros wrote: post #12

This is a nice hack, but I'm always very wary of playing with large voltages because it's too easy for things to go wrong. Instead, for controlling mains devices, I recommend a Sonoff S20: https://esphome.io/devices/sonoff_s20.html I usually flash ESPurna onto it (Tasmota and ESPhome are also good choices), it's very easy to do and it's extremely reliable and hopefully has a lower chance of fire than anything I'd mak…

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.

> properly taught

Key words the author did not write. While electrocution might be the first thing to come to mind, the ongoing risk of house fire might be the risk that best guides the (mis)use of hardware certified to perform a task.

Re: DIY IoT Fan

#23

Post by tzs »

stavros wrote: post #12

This is a nice hack, but I'm always very wary of playing with large voltages because it's too easy for things to go wrong. Instead, for controlling mains devices, I recommend a Sonoff S20: https://esphome.io/devices/sonoff_s20.html I usually flash ESPurna onto it (Tasmota and ESPhome are also good choices), it's very easy to do and it's extremely reliable and hopefully has a lower chance of fire than anything I'd mak…

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...

Re: DIY IoT Fan

#24

Post by airbreather »

baybal2 wrote: post #21
stavros wrote: post #12

This is a nice hack, but I'm always very wary of playing with large voltages because it's too easy for things to go wrong. Instead, for controlling mains devices, I recommend a Sonoff S20: https://esphome.io/devices/sonoff_s20.html I usually flash ESPurna onto it (Tasmota and ESPhome are also good choices), it's very easy to do and it's extremely reliable and hopefully has a lower chance of fire than anything I'd mak…

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.

220v is still a lethal voltage, and 220V at 10A is enough to sustain a nasty arc in the right circumstances.

An arc can have the temperature of four times the surface of the sun and will not neccesarily trip a noormal protective device due to its impedance.

Just for interest, vaporised copper has 67,000 times the volume of solid copper, this is why it makes quite a big bang.

I am an electrical engineer, most people do not fully understand the dangers of electricity and the lottery they play even at 110VAC.

The "physics" of electricty are tricky at all voltages, there are recorded cases of people dying from electric shock from a 24VDC truck battery.

Re: DIY IoT Fan

#25

Post by tecleandor »

tzs wrote: post #23
stavros wrote: post #12

This is a nice hack, but I'm always very wary of playing with large voltages because it's too easy for things to go wrong. Instead, for controlling mains devices, I recommend a Sonoff S20: https://esphome.io/devices/sonoff_s20.html I usually flash ESPurna onto it (Tasmota and ESPhome are also good choices), it's very easy to do and it's extremely reliable and hopefully has a lower chance of fire than anything I'd mak…

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 contr…

I'm looking for something similar: a power strip with all the outlets individually switchable. At least 4. So like a mix between that and a Sonoff S20.

Having three instead of four switchable outlets, and different "normally on" and "normally off" setting threw me off a bit.

Re: DIY IoT Fan

#27

Post by EricE »

stavros wrote: post #12

This is a nice hack, but I'm always very wary of playing with large voltages because it's too easy for things to go wrong. Instead, for controlling mains devices, I recommend a Sonoff S20: https://esphome.io/devices/sonoff_s20.html I usually flash ESPurna onto it (Tasmota and ESPhome are also good choices), it's very easy to do and it's extremely reliable and hopefully has a lower chance of fire than anything I'd mak…

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.

Re: DIY IoT Fan

#28

Post by EricE »

airbreather wrote: post #24
baybal2 wrote: post #21

Earlier quoted context omitted.

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.

220v is still a lethal voltage, and 220V at 10A is enough to sustain a nasty arc in the right circumstances. An arc can have the temperature of four times the surface of the sun and will not neccesarily trip a noormal protective device due to its impedance. Just for interest, vaporised copper has 67,000 times the volume of solid copper, this is why it makes quite a big bang. I am an electrical engineer, most people d…

>The "physics" of electricty are tricky at all voltages, there are recorded cases of people dying from electric shock from a 24VDC truck battery.

yes, that's because lethality is a combination of voltage, current and the location where those are applied to the body. Apply one charge to your foot? No problem. Apply the same charge to your chest right above your heart or in some configuration where the current flows through your heart? You are probably going to have a bad day :p

Re: DIY IoT Fan

#29

Post by EricE »

thirdhaf wrote: post #26

Neat hack, but why would you want a fan on the internet?

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

Re: DIY IoT Fan

#30

Post by EricE »

xenio wrote: post #7

I have the same fan, I'll love to control it with esp32. Is he using 3 relays to trigger on/off, rotation and speed? Also, from what I see, he is not detecting the previous state?

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.
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