How to build my own sensors?

can anyone guide me to the best way to build my own IOT device that feet my needs
i am not excepting diagrams or sketches just what is the right path?

there is a lot of youtube guides for sure…

but i don’t think they cover from design to product/ prototype,
so if any forums you know that can help or any guide that is useful …
or just tips for anyone that failed or succeed :slight_smile:


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Define your needs

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something like esp32 that I can connect relays, switches, buttens ,sensors of all sorts , all will be connected to power and wifi at all times

mqtt is must…

Have you already had a look at


Not just for sonoff devices

no thank you
looks very good!

yes i have it all ESPEasy , Tasmota
i want to know how to connect it good and have it working on daily base

sonoff is great for this but, its has a shortage in outputs/inputs

i will need something like 40 to have all my needs satisfied :slight_smile:
i want to build somthing like 5-6 that will cover all all needs outside the sonoffs

I use Sonoff basics as relays to turn off lights etc with mqtt and for temperature sensors Nodemcu with DHT11. If you’re using openhabian set up mosquito via openhabian-config. Then get your head around mqtt, your pi running Openhab will subscribe to a topic and your Sonoff basic that you have flashed with the correct firmware will publish your topic. A topic could be lounge/temperature etc. It takes a while to set up or to get your head around it but you’ll get there in the end.

Do you need all the 40 sensors on the same place?
I didnt get your intention fully. I use several Wemos D1 minis with different sensors (temperature, humidity, light (lux),wind, co2, pollution, motion, rf, ir…)
what do you need and for what? I like it that i can place everywhere sensors
wireless (only power) and get status via mqtt and i have 1 easy powerfull platform.

exactly… wemos will be great because of size…
what i am not sure about hot to do good power delivery …
how to do good housing for each one
(lux),wind, co2, pollution, motion, rf, this are things i also want to master
but right now doors windows switches buttons

The problem with ESPs is power. Battery powered ESPs can be done with deep sleep but then you have a time delay when they wake up and reconnect to the wifi.
My Battery sensors are made with and report to a master arduino connected to the network and publish on MQTT. Time lag = 0. Battery life on window sensors almost 2 years. Temp and hum sensors reporting every 5 minutes 1 year.

When I can I use powered ESPs: Fridge/Freezer, radiator valves…

Yes! I strongly support MySensors!
I am using a number of sensors since a few years back. Easy to build. Low cost.
All of them report to an MQTT GW and they send their data to a cloud service.
I actually have two GW in two different geographical locations but only one OpenHab instance.

OpenHab subscribes to the feeds and acts on the different measurements.

Or any other MQTT broker. You can adjust that in the gateway settings.

Yes, of course!
The reason for using a cloudservice for MQTT is that I have two geographical sites reporting measurements. I do not want to expose an MQTT-broker of my own outside my firewall for the remote site to access. Instead both sites report to and OpenHab subscribes to both streams. The mqtt-binding supports more than one subscriber name/password simultaneously.


Can I point you to this tutorial I wrote a while ago to get MQTT working with ssl and cloudmqtt

i got to say…
i am using node red for MQTT and rules and its pretty easy
openhab stills runs for all the items but conncting stuff with node red i just fun and simple