NodeMCU on ESP32

A Lua based firmware for ESP32 WiFi SOC

NodeMCU is an eLua based firmware for the ESP32 WiFi SOC from Espressif. The firmware is based on the Espressif IoT Development Framework and uses a file system based on spiffs. The code repository consists of 98.1% C-code that glues the thin Lua veneer to the SDK.

The NodeMCU firmware is a companion project to the popular NodeMCU dev kits, ready-made open source development boards with ESP8266-12E chips.

Summary

• Easy to program wireless node and/or access point
• Based on Lua 5.1.4 (without debug, os modules)
• Asynchronous event-driven programming model
• 10+ built-in modules
• Firmware available with or without floating point support (integer-only uses less memory)
• Up-to-date documentation at https://nodemcu.readthedocs.io

Programming Model

The NodeMCU programming model is similar to that of Node.js, only in Lua. It is asynchronous and event-driven. Many functions, therefore, have parameters for callback functions. To give you an idea what a NodeMCU program looks like study the short snippets below. For more extensive examples have a look at the /lua_examples folder in the repository on GitHub.

-- a simple HTTP server
srv = net.createServer(net.TCP)
srv:listen(80, function(conn)
	conn:on("receive", function(sck, payload)
		print(payload)
		sck:send("HTTP/1.0 200 OK\r\nContent-Type: text/html\r\n\r\n<h1> Hello, NodeMCU.</h1>")
	end)
	conn:on("sent", function(sck) sck:close() end)
end)

-- connect to WiFi access point
wifi.mode(wifi.STATION, true)

wifi.sta.on("connected", function() print("connected") end)
wifi.sta.on("got_ip", function(event, info) print("got ip "..info.ip) end)

-- mandatory to start wifi after reset
wifi.start()
wifi.sta.config({ssid="SSID", pwd="password", auto=true}, true)

Documentation

The entire NodeMCU documentation is maintained right in this repository at /docs. The fact that the API documentation is maintained in the same repository as the code that provides the API ensures consistency between the two. With every commit the documentation is rebuilt by Read the Docs and thus transformed from terse Markdown into a nicely browsable HTML site at https://nodemcu.readthedocs.io/en/dev-esp32/.

• How to build the firmware
• How to flash the firmware
• How to upload code and NodeMCU IDEs
• API documentation for every module

Support

See https://nodemcu.readthedocs.io/en/dev/en/support/.

License

MIT © zeroday/nodemcu.com