By coincidence I’m actually able to answer that. Because of this I’ve reworked the Pow article and can refer you to this comment
Besides that I can’t really recommend anything. The important thing you might need to remember is, that your consumer will probably have it’s own more or less constant rating. If you are powering a 5W lightbulb, setting MaxPower to whatever doesn’t make a difference, if you connect the Pow to a high power consumer, MaxPower will prove that your consumer is in fact not suited for the Pow. You should also differentiate between peak wattages and constant (mean) consumption. Only the latter is a problem.
In short: Set MaxPower to 2000 W and consider not using the possibly faulty Pows for high power consumers, observe them during a usual usage cycle to be safe.
I want to track the power usage of a side-by-side frige and a freezer… No idea what the max power of these things is, but i think it´s below 1 kW… So no problem so far?
And another question: Is there a cheap sensor with a few channel from sonoff also where i can flash the software?
Maybe you want to invest in one of those wattage meters to get a feeling for it. A freezer is far away form 1000W
If you want to use a Sonoff, the selection is limited. The Sonoff Basic offers 4 user IOs.
If you want to connect more and are not interested in the power relais of the Sonoff, just do the obvious and choose a microcontroller for the job. My choice would be the Wemos D1 mini.
Sonoff Basic only has 1 Output? But i need Binary Inputs for connectiong sensors. Which Sonoff is this? I haven´t found anything on the itead or sonoff website.
Sorry, i can´t solder, so no Wemos D1 mini for me…
I got result with measurement of low power loading with Sonoff POW.
First I set EnergyRes to 5.
I took Total value with Teleperiod=60s and compare it with previous value. Measurement is very accurate with resolution below 1W (compare with Power W from teleperiod stats). Here is grafana setting for Total measurement.
var Number WashingMachine_Consumption = (ESP_SonoffPOW1_Total.state as Number
- ESP_SonoffPOW1_Total.historicState(now.minusMinutes(1)).state as Number) * 60 * 1000
On the github page of Tasmota firmware, it’s stated that Sonoff Touch (name of the wall switches) is supported. I’ve ordered 3 and tried them with the Sonoff android application, but haven’t had time to solder connectors and flash Tasmota firmware. Anyway, since a lot of people are using it, I guess it shouldn’t be too much of a hassle to make it work.
I altered it, I do not remember the details, but it seems that the chip is not 8266, be careful. Everything works, but I did not use it, I did not like the quality, in addition to it I need to lay 3 wires, which is uncomfortable with the existing wiring.
Yes Yes Yes! So it was. I initially did not pay attention and stitched as 8266, later figured out and everything turned out. Just wanted to warn that others did not step on my rake
The only restriction one should be aware of is, that currently a double press action is implemented but not in a very useful manner. From my past experience the developer of Sonoff-Tasmota will have improved that soon
The Sonoff Touch are pretty and working without problems. Just remember that they are touch only which might confuse your guests or grandma…
Can I use this sonoff wall switch for switching only without connected lights too or can I only switch directly connected lights? I have knx installation, so no direct connection between switch and light.
It has a relay build in but you could of course not connect anything to it. The module will additionally send out MQTT messages, which you can use as the trigger to switch KNX devices via openHAB.
Thats the problem. With knx installation you don´t have 230V AC power on the places where you flush mount switches. There you only have knx-bus-wires on which you can send low power (like maybe 12V or 24V) through the wires.
I don´t have the usual knx installation with a ring for the knx bus, i have a central place in the middle of the house and there a extra tube to every outlet (in german: Sternverkabelung - star wiring). So maybe i can put 230V wires to the switches… Woulb be a cheap way to get switches all over the house.
KNX switches are expensive - and KNX touch switches are a way more expensive.
No four as I said. Three of them are accessible on the 5-pin header, see here: 
