[tbot] [DENX] [Knowledge sharing] Power strip IP device

Lukasz Majewski lukma at denx.de
Thu Feb 7 09:05:26 UTC 2019

Dear Wolfgang,

> Dear Lukasz,
> In message <20190207082231.5a205ae3 at jawa> you wrote:
> >
> > Recently I was forced to poke around for a good quality power strip
> > device (my previous one is EOL).
> >
> > The one, which I've found (and tested):
> >
> > https://www.antratek.com/netio4all-remote-controlled-power-sockets-with-metering?___SID=U  
> Hm.... more than 300€ for just for sockets is pretty expensive, I
> think.

Maybe I was lucky - 230 EUR with shipment (including tax) - from local

> I've been playing around with these things for more than 25 years,
> and I never understood why such solutions have to be so expensive.

I think that one pays for all the "whistles" - web interface, (this has
JSON API, XML API, Secure WebAPI, MQTT, SNMP, telnet (secure), etc), BT
4.0, WiFi.

This version also measures drawn energy (which is also accessible via
snmp) - good for power consumption regressions measurement.

> I've always targeted for less expensive stuff...

When the system "grow" to be a test farm - the vlab approach would be

For now - this is the "initial" setup phase.

> I'm in the process of setting up the VLAB in Happurg, and there I
> finally want to get rid of the old radio controlled switches.  What
> I'm using now is WiFi controlled devices like the 
> 	"Wifi Stecker Schuko" [1]
> which you can buy at OBI for just 10€.  You don't want to run it
> with the original firmware which uses some Chinese cloud server, but
> it is trivial to flash the free Tasmota [2] firmware, so you can use
> for example MQTT (with encryption) to control the devices.
> I know that some of you (hey Marek :-) ) categorically object to the
> idea of controlling infrastructure over WiFi, but it gives you
> really nice flexibility and it scales much better than any other
> solution I had before,

It seems like Marek is not alone here :-)

> Looking at the internals you will find that the deevice is based on
> the ESP8266 controller, which is also used in a zillion other
> devices, especially the devices of the "Sonoff" family.  And all
> these run the Tasmota firmware as well.
> So if you need to address another area of remote controling devices
> (like remote operation of reset button or boot mode jumpers etc.) 
> you can for example use a Sonoff 4CH Pro R2 mit Tasmota firmware
> which gets you 4 relays you can operate over wifi for just 14€.

When I will be forced to connect more than 4 (8?) devices (which are
pretty power hungry) - then not only scale matter, but also the power
output from the supply.

But Yes, PC power supply with high quality relays scales better.

> What I really like with this system is:
> - The devices are much cheaper than any alternatives.
> - You can start with minimal size and grow as you go.
> - The system scales well - it does not matter if you have 10 or 50
>   devices in the network.

Can you recommend any 12/24V power supply? (Either standalone or U rack
one?). Or do you use "normal" PC power supply

> - It integrates different functions (sockets, relays, sensors) in one
>   system using standard protocols, so you can add any fancy user
>   interface you like.

Maybe it is a time to look into control via MQTT ...

> - It is not limited to one room, not even to one location.  Assuming
>   you have proper connectivity (say by VPN), you can control devices
>   at several locations using one system.
> I really think such an approach is much more interesting than any
> specific individual devices you can buy.

It seems so. As said before - I do want to have working prototype first
(with tbot).

And I can confirm that this particular power strip can be controlled
via snmp v3 under tbot.

> Disclaimer: in the VLAB setup in Happurg I'm still experimenting,
> using the (insecure) web interface.  I didn't succeed yet in
> controlling the devices using MQTT (with encryption), but this is
> only due to lack of time and my own incompetence. [Any help with
> that welcome! :-) ]

I do cross fingers, as I may want to reuse your setup as it scales
better (for more than 8 devices)

> [1]
> https://www.obi.de/hausfunksteuerung/wifi-stecker-schuko-weiss/p/4077806
> [2] https://github.com/arendst/Sonoff-Tasmota [3]
> https://www.banggood.com/de/SONOFF-4CH-R2-4-Channel-10A-2200W-2_4Ghz-Smart-Home-WIFI-Wireless-Switch-APP-Remote-Control-p-1254823.html?gmcCountry=DE&currency=EUR&createTmp=1&utm_source=googleshopping&utm_medium=cpc_bgs&utm_content=frank&utm_campaign=pla-mix-de-pc-0124&ad_id=327381820946&gclid=EAIaIQobChMI-JnFr5ap4AIVyuF3Ch1yRQl9EAQYAiABEgI7AfD_BwE&cur_warehouse=CN
> Best regards,
> Wolfgang Denk

Best regards,

Lukasz Majewski


DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma at denx.de
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