f3e2a3afd9
This compiles, links, and starts the RTOS without crashing and burning.
Lua environment does not yet start due to the different task architecture.
Known pain points:
- task implementation needs to be rewritten for RTOS (next up on my TODO)
- secure espconn does not exist, all secure espconn stuff has been #if 0'd
- lwip now built from within the RTOS SDK, but does not appear to include
MDNS support. Investigation needed.
- there is no access to FRC1 NMI, not sure if we ever actually used that
however. Also #if 0'd out for now.
- new timing constraints introduced by the RTOS, all use of ets_delay_us()
and os_delay_us() needs to be reviewed (the tsl2561 driver in particular).
- even more confusion with ets_ vs os_ vs c_ vs non-prefixed versions.
In the long run everything should be switched to non-prefixed versions.
- system_set_os_print() not available, needs to be reimplemented
- all the RTOS rodata is loaded into RAM, as it apparently uses some
constants while the flash isn't mapped, so our exception handler can't
work its magic. This should be narrowed down to the minimum possible
at some point.
- with each task having its own stack in RTOS, we probably need change
flash-page buffers from the stack to the heap in a bunch of places.
A single, shared, page buffer *might* be possible if we limit ourselves
to running NodeMCU in a single task.
- there's a ton of junk in the sdk-overrides now; over time the core code
should be updated to not need those shims
NodeMCU 1.5.1
A Lua based firmware for ESP8266 WiFi SOC
NodeMCU is an eLua based firmware for the ESP8266 WiFi SOC from Espressif. The firmware is based on the Espressif NON-OS SDK 1.5.1 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
- 40+ 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(conn, payload)
print(payload)
conn:send("<h1> Hello, NodeMCU.</h1>")
end)
conn:on("sent", function(conn) conn:close() end)
end)
-- connect to WiFi access point
wifi.setmode(wifi.STATION)
wifi.sta.config("SSID", "password")
Documentation
The entire NodeMCU documentation is maintained right in this repository at /docs. The fact that the API documentation is mainted 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.
- 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
Build Options
The following sections explain some of the options you have if you want to build your own NodeMCU firmware.
Select Modules
Disable modules you won't be using to reduce firmware size and free up some RAM. The ESP8266 is quite limited in available RAM and running out of memory can cause a system panic. The default configuration is designed to run on all ESP modules including the 512 KB modules like ESP-01 and only includes general purpose interface modules which require at most two GPIO pins.
Edit app/include/user_modules.h and comment-out the #define statement for modules you don't need. Example:
...
#define LUA_USE_MODULES_MQTT
// #define LUA_USE_MODULES_COAP
// #define LUA_USE_MODULES_U8G
...
Tag Your Build
Identify your firmware builds by editing app/include/user_version.h
#define NODE_VERSION "NodeMCU 1.5.1+myname"
#ifndef BUILD_DATE
#define BUILD_DATE "YYYYMMDD"
#endif
Set UART Bit Rate
The initial baud rate at boot time is 115200bps. You can change this by
editing BIT_RATE_DEFAULT in app/include/user_config.h:
#define BIT_RATE_DEFAULT BIT_RATE_115200
Note that, by default, the firmware runs an auto-baudrate detection algorithm so that typing a few characters at boot time will cause the firmware to lock onto that baud rate (between 1200 and 230400).
Debugging
To enable runtime debug messages to serial console edit app/include/user_config.h
#define DEVELOP_VERSION