IoT device monitor

After having about 18 IoT devices, mainly powered by battery, I experienced that I got no information whether the devices were up and running or dead. Some devices the battery drains in half a year. So I had to get this information on a panel so that I discover early that a device or system is dead.

As a result I builded an IoT device monitor/LED panel that give me information about the status. First look at the pictures/video.

The WS2812B LED panel (aliexpress)
The wooden frame (self made) with power input and switch (LEDs on/off)
3mm Polycarbonate opal white plate
ESP32 microcontroller (WiFi)
The result, data of 1 devices is received (green)
Monting IoT devices

Technical background

The ESP32 works like a webserver that can receive API calls. Its calls looks like http://<server ip>/leds/<nr>/<color> Whenever such a API call is made the timer start (15 minutes) and the corresponding led will be green (or color) for 10 seconds. When the timer counts to 0, the led will glow from white to orange. After 15 minutes the led wil go red. When a new API call is made the timers are reset. In the video you can see other leds blink. This is a side effect of the mismatch of electronic signal from the ESP32 and the panel. I left this so it seems there is a lot of action going on. For me the leftside leds are most important. Most of my devices sends data within 5-10 minutes range, so there will be no red leds if my systems are working fine.

I make the API call whenever a device is sending data to a logserver. Every device that I make is sending data. When this system is down eventually all leds will get red. If a subsystem (LoRa or NBIoT for example) is down, a few will led up green.
A small switch is added on the left topside to switch the LEDs off. During night or when I get mad of the blinking leds…

2 thoughts on “IoT device monitor

  1. joba1

    Nice project … again! I currently struggle to make your attiny84/lorawan code work for me. It looks like it sends fine, but TTN ignores me 😀
    If you want to get rid of the flickering, try this: 74AHCT125N DIP-14 4x 3.3v –> 5v level shifter. 1x for Din would be enough, but this is what I use.

  2. Leo Post author

    Hello Joachim,

    Pitty that your lorawan node doesn’t work well. Do you have your own gateway?
    For me, it was necessary to build my own gateway because there were no reliable TTN gateways in my neighborhood.
    If you do not have a gateway you can build your own single channel gateway, the cheapest solution with a RMF95 module and Raspberry Pi and tweak my code on the LoraWan node to send only on 1 channel.

    Thanks for your advice on the flickering. I tried already a 74AHCT126N but that did not solve the flickering.
    I do not bother much because now i looks like there happens a lot and it looks like some panels you see in fantasy movies with spaces crafts.
    Maybe I try once your 125 chip.

    With kind regards,


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