Regular readers may know that I like ambient devices: devices that fit into the environment unobtrusively and provide information at a glance. One such device is my bus monitor that shows times of buses at the stop near my house. Recently I decided to solve the problem of answering the question "Do I need an umbrella?" when I leave the house. For this I chose to use an ESP8266 in the form of a NodeMCU running Lua and display the coming weather by illuminating the eyes on a small Totoro figure. This was my first NodeMCU/ESP8266 project and there's definitely a bit of a learning curve. I ended up using luatool to upload my Lua code to the device, and esptool to flash the firmware using a custom firmware build from this wonderful website with the following modules present: cjson , file , gpio , http , net , node , tmr , uart , wifi , and ws2812 . ./esptool.py --port /dev/cu.SLAB_USBtoUART write_flash -fm qio 0x00000 nodemcu-master-10-modules-2017-04-08-