I think it’s great that the author did this as a learning experience. It seems like soldering on a few wires could have saved you like 3 weeks.. but anyway, the ESP8266 is a great platform. Super cheap, minimal components, easy to program, you can write code natively using the SDK or various script based languages. And has good support from the manufacturer.
Reprogramming a $13 consumer wifi-enabled outlet
21–30 of 44 posts
Re: Reprogramming a $13 consumer wifi-enabled outlet
#22wifi seems overkill to send on off signals. i would use 433mzh
Except in the US as this frequency is used for amateur radio.
Even through that's true, there's still a wealth of devices that ignore that and use it anyway unfortunately. Mostly cheap devices from other countries that I suspect aren't properly fcc certified despite any claims to the contrary. The wireless doorbell at my last place was on 433mhz.
Re: Reprogramming a $13 consumer wifi-enabled outlet
#23Earlier quoted context omitted.
> never, ever connect UART while the device is plugged into AC!! Why?
If I remember right, some very low cost ways of converting AC to DC for small electronics leave those electronics at high voltage relative to ground. So the device itself sees +5V relative to its "ground", but the device "ground" might actually be at, say, 115V and the supply at 120 to make 5V. Thus the UART pins might also be at high absolute voltage. This is fine for devices that are fully isolated.
The "POW" device is one example of a device which has GND at live potential, so should not be connected to anything else while plugged into the mains.
Not that I would recommend plugging any of them into the mains with the case removed, or while plugged into other wiring, to be sure!
Re: Reprogramming a $13 consumer wifi-enabled outlet
#24This looks quite similar to the Sonoff S20. [1] Although they opted for the ESP module instead of designing a custom PCB around the ESP8266 chip as Sonoff does. According to the S20 schematic, uart is routed to a header, so it should be easier to flash. [2] The Sonoff S20 is the same price as the mentioned model, and is supported by espurna. [3] Espurna is great, it has MQTT, Domoticz, Home Assistant, an HTTP API, an…
It should be noted that Sonoff devices are not UL Listed, unlike the device the article discusses. Given that and how Chinese product companies like to cut corners with these type of devices (see bigclivedotcom on YouTube), I’m not sure I’d trust connecting one of these to mains voltage.
From looking over their schematics and layout, they are fairly well designed, and they have gone through CE certification so fine for European consumers.
No UL certification could be an issue for US consumers though.
Re: Reprogramming a $13 consumer wifi-enabled outlet
#25I've noticed a big market gap, ever since I got an electric car. Every EV owner has a 120V AC charger that they can plug in almost anywhere with an outlet, however getting permission is a challenge. Owners of the outlets rightfully want compensation. But a full commercial charger rig is like $1000 at least. That's way too much!
What I'd like is for outlets to have wifi or bluetooth connectivity on them. I just tell the outlet to turn on via some app, and the app/outlet keep track of how long the outlet is on and charges me a flat rate per unit time. Simple. The smarts for this need only cost $13 above what a regular outlet costs, as this project shows.
This would be especially useful in apartments or parking garages. Provided you already have lights, it'd be cheap to run a 120V outlet to within reach of most (or at least a large number of) parking spots. $13 of electronics plus maybe $50 (i.e. a quad outlet of $200 split among 4) to install an outdoor outlet is all it'd cost to electrify a parking space. The owner of the parking lot could offer low cost electricity and, say, make a profit off the difference between residential and commercial/industrial electrical rates (might take a few months to pay for the outlet, but not more than a year for a well-used spot, then the owner makes an easy profit). Everyone wins, and urban EVs become practical for everyone (and a slow charge is fine. of course, you would still want fast chargers to top up if you were doing a lot of driving, but that can be done elsewhere). Also would be pretty cheap to install on all parking meters.
Just need someone to develop that app and an outdoor outlet with a $13 bluetooth relay that talks to the user's app (only the user's app would necessarily need internet connectivity). Someone do this and be a hero.
Re: Reprogramming a $13 consumer wifi-enabled outlet
#26I've noticed a big market gap, ever since I got an electric car. Every EV owner has a 120V AC charger that they can plug in almost anywhere with an outlet, however getting permission is a challenge. Owners of the outlets rightfully want compensation. But a full commercial charger rig is like $1000 at least. That's way too much! What I'd like is for outlets to have wifi or bluetooth connectivity on them. I just tell t…
A quad 120V 20A outlet suitable for charging 4 cars is going to take a lot more than $200 to install in most commercial locations, they'll either need to install an 80A subpanel near the outlet with 4 20A breakers, or home run 4 20A circuits to the main panel.
If the main panel is out of spare breaker slots (or doesn't have enough amperage left on the feeder), it's going to expensive to upgrade the panel.
Most of the cost ends up in labor, so if you're going to go to all of the expense to install a 4x20A quad outlet, you may as well install a 30A 240V level 2 charge station.
Most of that cost is labor -- I looked into installing a charge station in my condo apartment garage -- coring and installing a home run back to the main panel would have cost $3000 - $5000, and I would have had to pay for a power study for the HOA owned panel.
There wouldn't have been much difference in materials cost between installing a 120V 20A circuit for level 1 charging and a 30A 220VAC level2 charge station.
Re: Reprogramming a $13 consumer wifi-enabled outlet
#27Earlier quoted context omitted.
It should be noted that Sonoff devices are not UL Listed, unlike the device the article discusses. Given that and how Chinese product companies like to cut corners with these type of devices (see bigclivedotcom on YouTube), I’m not sure I’d trust connecting one of these to mains voltage.
From looking over their schematics and layout, they are fairly well designed, and they have gone through CE certification so fine for European consumers. No UL certification could be an issue for US consumers though.
I understand CE to basically be self certified. It’s good but mostly meaningless when compared to bring UL listed or higher, which require equipment tests as well as frequent drop in visits from UL people to your manufacturing fascilies.
Re: Reprogramming a $13 consumer wifi-enabled outlet
#28While DIY can be fun, I prefer to buy a finished product when there's a solution readily available... Especially when dealing with home wiring.
When faced with a similar problem (big room, wanted to control multiple lights without pulling wires), I used an Insteon battery operated remote switch:
https://www.smarthome.com/insteon-2342-242-mini-remote-switc... ($42)
And an inline switch module that went up in the ceiling light housing: https://www.smarthome.com/insteon-2443-222-micro-on-off-modu... ($49)
And a couple plug in lamp modules:
https://www.smarthome.com/lamplinc-insteon-2457d2-plug-in-la... ($39)
One advantage of the off the shelf products is that they are all UL approved for the use, so if it catches fire and burns my house down, I don't have to prove that it wasn't my fault.
Re: Reprogramming a $13 consumer wifi-enabled outlet
#29I really enjoyed reading this, but it wasn't entirely clear to me what the author planned to reprogram the unit to actually do. So from my perspective, the article ended abruptly when the author declared success even though I was looking forward to a description of the conclusion. The story is important and often overlooked in these moments. It's what justifies spending a hundred hours and $200 to achieve something y…
If you read the entire article it's clear why he's reprogramming them. You have to fully read the first two paragraphs.
But essentially, he reprograms the smart plugs to respond to a simple HTTP GET request to turn the lights on, and then turn the lights off after 11 seconds, and the 11 second countdown can be reset by hitting that HTTP endpoint again.
He has a "sensor" board that has a light sensor, and when he turns his regular light switch on, that sensor board detects the light in the room, and hits all the smart plugs endpoints to turn them on. As long as that sensor board detects light, it will keep hitting the "lights on" endpoints of the smart plugs.
When he turns his regular light switch off, the sensor board stops hitting the "lights on" endpoints, and the lights automatically turn off after 11 seconds.
Re: Reprogramming a $13 consumer wifi-enabled outlet
#30I use tp-link hs110, Wi-Fi enabled metering plugs. Highly recommended.