I was looking for another inspiration after completion of my previous project (WiFi-433Mhz bridge). I have found, that there is something interesting that I can measure with my "iot device construction skills" :)

I have read an article at EngineerAtHome about measuring energy consumption based on counting black line passings. So I quickly decided that would be great to construct my own device based on that idea.


Project uses ESP12F (but ESP07 footprint), AMS1117 LDO occupied with some capacitors for power stability. There are also two LEDs (with their resistors), driven from code and also I2C, UART and SENSOR ports. By the way, I am still not using I2C, because there is no need to at this moment.


Designing PCB was not a big challenge. Completed that just in few hours. Boards arrived very quickly, thanks to Elecrow. I have paid only 0.99$ fot 10pcs, because of amazing annual promotion! Excellent quallity, cheap shipping.


I have used Visual Micro, great Visual Studio plugin that allows to code in Arduino framework. There is of course Arduino port for esp8266 WiFi chip. It took around a week or two to write good, working software. My friend gave me VPS access and hosted MQTT broker for me. Yes, using MQTT again was a great choice.

Another thing was to "republish" values somehow to 3rd party services. I have used Thingspeak as first, but decided to switch to Beebotte due to lack of 15 seconds cap between messages. I wrote small PHP script that runs via php.exe on VPS that forwards messages to Beebotte service - of course I can use MQTT Bridge on Beebotte, but this was impossible to do so on Thingspeak, so I decided to stick with my script. It is working, so why not?

FInally... working dashboard at beebotte :)