Multip Smart power strip

Dear community,

After few months of hard work on this project, I finally have a finished product. If some of you remember, I already used industry grade Multip power strip in my home automation system. So I continued with improvements both on hardware and coding side in order to make it the smartest power strip ever, and this is a final result. So let me introduce you to Multip Smart.

HW Basics: first socket with red led is always on, passive socket. Other two, marked with yellow and green leds are active, Blynk controlled sockets. System is based on Wemos Mini D1, two power supplies, two relays, BME280 and ACS712 sensors. BME is separated from power strip in order to get realistic ambient data, as all temperature sensors are very sensitive to background heat. USB cable I used for the sensor is 1.5m long, housing for BME is custom made by my good friend. Second USB connector can be used as a phone charger. It also has delta config surge protection up to 15.000A, and relays are optoisolated from mcu.


Control tab: two buttons for active sockets, three Time input widgets available per socket, and Eventor is taking care of actions and notifications triggered by weather/energy conditions. Every time input widget has dedicated status led, so one look at the app tells you if and which timer is active at the moment. There is also reset button which you have to push and hold for 5 seconds if you want to reset the module, and wifi signal strength display. If you want to use more than one Multip, there is also Selector available.

Energy tab: measures current, power, power consumption and monthly cost, followed by Super Chart

Weather tab: measures temperature, humidity, air pressure and dew point, using Super Chart once again

Location tab: rtsp / yt video stream and GPS triggering.

Super chart on Weather tab looks much better after some time of usage, sorry for this pic, but I don’t have any other with user interface in English. This is how it looks like on my Multip:

More pictures:

Multip Smart is also OTA enabled and uses wifi manager for provisioning.

Building this product would not be possible without Blynk, this fabulous community, and last but not least, my friend @Costas, who helped a lot with the code and testing of the product, as he is an owner of one of the early Multip prototypes.


Nice writeup! I’m curious how do you use the ACS712? Does it need to be near a cable which you want to detect or is it connected in line somehow?

ACS712 always breaks live line, so cable cut is necessary in this case.


do you also calculate power factor somehow, and measure actual voltage? or just have a hardcoded value for voltage and pf?

Yes, there are sliders like in ESPecoMon, just one empty row under the SuperChart in Energy tab, you have to scroll down to reach them. They are hidden to eliminate unintentional use. There’s no voltage measuring with ACS712, only current, so voltage value is set by code/slider.


This will be a real challenge.

It looks very professional I must say! Both on the hardware and software side. I just have a little tip for improving display. How about using RGB leds as status indicator? You may also be able then to adjust a socket for “passive”. E.g. I want to have three always-on sockets (configurable in EEPROM so it always turns on?). Than you could use different colors for indicating status. E.g. Green manually on, Purple on timed mode due to weather, orange for simple on/off timers and so on.

Really curious to the next power strip! I need to make one too, but my 8 relay board is too big, I need to order a different one lol. I also plan on using an industry grade (datacenter-like) strip.

Very nice project!!!
Do you intent to share your code as well as Blynk QR code with us?

This is interesting, but passive, always on sockets are not controlled by mcu, so red led is just an indicator for that, it’s not connected to relay board or mcu. Active sockets are covered with leds in same color like buttons in the app, and they are there just to show if socket is activated or not. I didn’t plan to make led indicators for anything else, as it would be hw overkill, it’s just a power strip after all :slight_smile:

Well, yes, but more functions make it more interesting :smiley:

It will most probably be available as one of the Faces in ESPproMon app, I’ll keep you informed. Code and app are useless without hardware anyway.

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As you can imagine, I’m very, very restricted when talking about space, Multip is already full of power supplies, sensors, connectors and wires. It’s complicated enough already, adding anything else would be real trouble.

I would not recommend using 8-relay boards at all, at least not with ESP.

It would probably require a bit more power, but I think it’s pretty much doable with a decent 5v supply. I’ve never ran into any problems switching with 8 relays :slight_smile:

But I admit, it will be a big powerstrip, haha. I think I’ll start with something smaller :slight_smile:

You will be fine with 4-relay board. I have two 8-way boards, and I’m not happy with them at all, at least one relay per board was weak and not working properly.

Where did you get the hardware ? I mean the strip itself.

It’s locally available in Serbia only.

congratulations for your project.

very good project !
Looking forward to seeing your code !!!

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