Some time ago I have built a WiFi thermometer with a NodeMCU and a 6Ah recycled nickel-cadmium battery. WiFi is probably the least power-efficient communication methods, but I was curious how long could a NodeMCU run from a big battery pack.
It took some time to get meaningful data…
Continue reading “Practical NodeMCU endurance with a big NiCd battery pack”
I finally completed work on my networked thermometer. I got some old 7Ah 5-cell NiCd battery packs from emergency lighting fixtures that will power the device. I wonder how long can they last. NiCd batteries suffer from high self-discharge rates, on the other hand the NodeMCU will sleep most of the time and use very little energy.
Continue reading “NodeMCU as a standalone thermometer”
In the last post I made a short introduction on development using the NodeMCU platform with a simple reading of a 1-wire thermometer. This time I will show how to make a basic networked application for the NodeMCU and the server part for a computer to gather some useful data.
The idea is pretty simple: do a temperature conversion, connect to a wireless network, transmit the reading to a server, maybe get back some configuration and start over.
Continue reading “NodeMCU networked thermometer”
NodeMCU is a versatile board with the WiFi-enabled ESP8266 system-on-chip, USB to UART bridge, voltage regulator and some auxiliary components. With a price tag of about $9 on Aliexpress it allows you develop your own Internet “things” literally in minutes. The killer part is a build-in Lua interpreter, so no toolchain or development kit is required. The language is pretty easy. Text files containing Lua scripts are simply uploaded to the board and executed directly by the interpreter inside ESP8266. You can also type the commands directly via the terminal. NodeMCU firmware can also be uploaded to any ESP8266 module like the ESP-01, ESP-07 or bare ESP-12.