Impressed with NodeMCU

NodeMcu is a Lua interpreter with a good set of support libraries for the far-too-cheap ESP8266. I’m impressed with how easy it is to script up a Wifi connected thermometer using a DS18B20 1-wire thermometer, MQTT for publishing, and Wifi to a OpenWRT router for the transport.

Have a look at the NodeMcu git repo for the bundled libraries which include a JSON parser, MQTT, spifs, and software based I2C, 1-wire, and PWM drivers.

It’s very RAM hungry though. I had a hack and got it up to 25 k of free heap, but that’s only just enough for a single device and MQTT connection.