# node Module | Since | Origin / Contributor | Maintainer | Source | | :----- | :-------------------- | :---------- | :------ | | 2014-12-22 | [Zeroday](https://github.com/funshine) | [Zeroday](https://github.com/funshine) | [node.c](../../app/modules/node.c)| The node module provides access to system-level features such as sleep, restart and various info and IDs. ## node.bootreason() Returns the boot reason and extended reset info. The first value returned is the raw code, not the new "reset info" code which was introduced in recent SDKs. Values are: - 1, power-on - 2, reset (software?) - 3, hardware reset via reset pin - 4, WDT reset (watchdog timeout) The second value returned is the extended reset cause. Values are: - 0, power-on - 1, hardware watchdog reset - 2, exception reset - 3, software watchdog reset - 4, software restart - 5, wake from deep sleep - 6, external reset In general, the extended reset cause supercedes the raw code. The raw code is kept for backwards compatibility only. For new applications it is highly recommended to use the extended reset cause instead. In case of extended reset cause 3 (exception reset), additional values are returned containing the crash information. These are, in order, [EXCCAUSE](https://arduino-esp8266.readthedocs.io/en/latest/exception_causes.html), EPC1, EPC2, EPC3, EXCVADDR, and DEPC. #### Syntax `node.bootreason()` #### Parameters none #### Returns `rawcode, reason [, exccause, epc1, epc2, epc3, excvaddr, depc ]` #### Example ```lua _, reset_reason = node.bootreason() if reset_reason == 0 then print("Power UP!") end ``` ## node.chipid() Returns the ESP chip ID. #### Syntax `node.chipid()` #### Parameters none #### Returns chip ID (number) ## node.compile() Compiles a Lua text file into Lua bytecode, and saves it as .lc file. #### Syntax `node.compile("file.lua")` #### Parameters `filename` name of Lua text file #### Returns `nil` #### Example ```lua file.open("hello.lua","w+") file.writeline([[print("hello nodemcu")]]) file.writeline([[print(node.heap())]]) file.close() node.compile("hello.lua") dofile("hello.lua") dofile("hello.lc") ``` ## node.dsleep() Enters deep sleep mode, wakes up when timed out. Theoretical maximum deep sleep duration can be found with [`node.dsleepMax()`](#nodedsleepmax). ["Max deep sleep for ESP8266"](https://thingpulse.com/max-deep-sleep-for-esp8266/) claims the realistic maximum be around 3.5h. !!! caution This function can only be used in the condition that esp8266 PIN32(RST) and PIN8(XPD_DCDC aka GPIO16) are connected together. Using sleep(0) will set no wake up timer, connect a GPIO to pin RST, the chip will wake up by a falling-edge on pin RST. #### Syntax `node.dsleep(us, option, instant)` #### Parameters - `us` number (integer) or `nil`, sleep time in micro second. If `us == 0`, it will sleep forever. If `us == nil`, will not set sleep time. - `option` number (integer) or `nil`. If `nil`, it will use last alive setting as default option. - 0, init data byte 108 is valuable - \> 0, init data byte 108 is valueless - 0, RF_CAL or not after deep-sleep wake up, depends on init data byte 108 - 1, RF_CAL after deep-sleep wake up, there will be large current - 2, no RF_CAL after deep-sleep wake up, there will only be small current - 4, disable RF after deep-sleep wake up, just like modem sleep, there will be the smallest current - `instant` number (integer) or `nil`. If present and non-zero, the chip will enter Deep-sleep immediately and will not wait for the Wi-Fi core to be shutdown. #### Returns `nil` #### Example ```lua --do nothing node.dsleep() --sleep μs node.dsleep(1000000) --set sleep option, then sleep μs node.dsleep(1000000, 4) --set sleep option only node.dsleep(nil,4) ``` #### See also - [`wifi.suspend()`](wifi.md#wifisuspend) - [`wifi.resume()`](wifi.md#wifiresume) - [`node.sleep()`](#nodesleep) - [`node.dsleepMax()`](#nodedsleepmax) ## node.dsleepMax() Returns the current theoretical maximum deep sleep duration. !!! caution While it is possible to specify a longer sleep time than the theoretical maximum sleep duration, it is not recommended to exceed this maximum. In tests documented at ["Max deep sleep for ESP8266"](https://thingpulse.com/max-deep-sleep-for-esp8266/) the device never woke up again if the specified sleep time was beyond `dsleepMax()`. !!! note This theoretical maximum is dependent on ambient temperature: lower temp = shorter sleep duration, higher temp = longer sleep duration #### Syntax `node.dsleepMax()` #### Parameters none #### Returns `max_duration` #### Example ```lua node.dsleep(node.dsleepMax()) ``` #### See also - [`node.dsleep()`](#nodedsleep) ## node.flashid() Returns the flash chip ID. #### Syntax `node.flashid()` #### Parameters none #### Returns flash ID (number) ## node.flashindex() Returns the function reference for a function in the [LFS (Lua Flash Store)](../lfs.md). #### Syntax `node.flashindex(modulename)` #### Parameters `modulename` The name of the module to be loaded. If this is `nil` or invalid then an info list is returned #### Returns - In the case where the LFS in not loaded, `node.flashindex` evaluates to `nil`, followed by the flash mapped base addresss of the LFS, its flash offset, and the size of the LFS. - If the LFS is loaded and the function is called with the name of a valid module in the LFS, then the function is returned in the same way the `load()` and the other Lua load functions do. - Otherwise an extended info list is returned: the Unix time of the LFS build, the flash and mapped base addresses of the LFS and its current length, and an array of the valid module names in the LFS. #### Example The `node.flashindex()` is a low level API call that is normally wrapped using standard Lua code to present a simpler application API. See the module `_init.lua` in the `lua_examples/lfs` directory for an example of how to do this. ## node.flashreload() Reload the [LFS (Lua Flash Store)](../lfs.md) with the flash image provided. Flash images are generated on the host machine using the `luac.cross`commnad. #### Syntax `node.flashreload(imageName)` #### Parameters `imageName` The name of a image file in the filesystem to be loaded into the LFS. #### Returns `Error message` LFS images are now gzip compressed. In the case of the `imagename` being a valid LFS image, this is expanded and loaded into flash. The ESP is then immediately rebooted, _so control is not returned to the calling Lua application_ in the case of a successful reload. This reload process internally makes two passes through the LFS image file; and on the first it validates the file and header formats and detects any errors. If any is detected then an error string is returned. ## node.flashsize() Returns the flash chip size in bytes. On 4MB modules like ESP-12 the return value is 4194304 = 4096KB. #### Syntax `node.flashsize()` #### Parameters none #### Returns flash size in bytes (integer) ## node.getcpufreq() Get the current CPU Frequency. #### Syntax `node.getcpufreq()` #### Parameters none #### Returns Current CPU frequency (number) #### Example ```lua do local cpuFreq = node.getcpufreq() print("The current CPU frequency is " .. cpuFreq .. " MHz") end ``` ## node.heap() Returns the current available heap size in bytes. Note that due to fragmentation, actual allocations of this size may not be possible. #### Syntax `node.heap()` #### Parameters none #### Returns system heap size left in bytes (number) ## node.info() Returns NodeMCU version, chipid, flashid, flash size, flash mode, flash speed, and Lua File Store (LFS) usage statics. #### Syntax `node.info()` #### Parameters none #### Returns - `majorVer` (number) - `minorVer` (number) - `devVer` (number) - `chipid` (number) - `flashid` (number) - `flashsize` (number) - `flashmode` (number) - `flashspeed` (number) #### Example ```lua majorVer, minorVer, devVer, chipid, flashid, flashsize, flashmode, flashspeed = node.info() print("NodeMCU "..majorVer.."."..minorVer.."."..devVer) ``` ## node.input() Submits a string to the Lua interpreter. Similar to `pcall(loadstring(str))`, but without the single-line limitation. !!! attention This function only has an effect when invoked from a callback. Using it directly on the console **does not work**. #### Syntax `node.input(str)` #### Parameters `str` Lua chunk #### Returns `nil` #### Example ```lua sk:on("receive", function(conn, payload) node.input(payload) end) ``` #### See also [`node.output()`](#nodeoutput) ## node.output() Redirects the Lua interpreter output to a callback function. Optionally also prints it to the serial console. !!! caution Do **not** attempt to `print()` or otherwise induce the Lua interpreter to produce output from within the callback function. Doing so results in infinite recursion, and leads to a watchdog-triggered restart. #### Syntax `node.output(function(str), serial_debug)` #### Parameters - `output_fn(str)` a function accept every output as str, and can send the output to a socket (or maybe a file). - `serial_debug` 1 output also show in serial. 0: no serial output. #### Returns `nil` #### Example ```lua function tonet(str) sk:send(str) end node.output(tonet, 1) -- serial also get the Lua output. ``` ```lua -- a simple telnet server s=net.createServer(net.TCP) s:listen(2323,function(c) con_std = c function s_output(str) if(con_std~=nil) then con_std:send(str) end end node.output(s_output, 0) -- re-direct output to function s_ouput. c:on("receive",function(c,l) node.input(l) -- works like pcall(loadstring(l)) but support multiple separate line end) c:on("disconnection",function(c) con_std = nil node.output(nil) -- un-regist the redirect output function, output goes to serial end) end) ``` #### See also [`node.input()`](#nodeinput) ## node.readvdd33() --deprecated Moved to [`adc.readvdd33()`](adc/#adcreadvdd33). ## node.restart() Restarts the chip. #### Syntax `node.restart()` #### Parameters none #### Returns `nil` ## node.restore() Restores system configuration to defaults using the SDK function `system_restore()`, which is described in the documentation as: > Reset default settings of following APIs: `wifi_station_set_auto_connect`, `wifi_set_phy_mode`, `wifi_softap_set_config` related, `wifi_station_set_config` related, `wifi_set_opmode`, and APs’ information recorded by `#define AP_CACHE`. #### Syntax `node.restore()` #### Parameters none #### Returns `nil` #### Example ```lua node.restore() node.restart() -- ensure the restored settings take effect ``` ## node.setcpufreq() Change the working CPU Frequency. #### Syntax `node.setcpufreq(speed)` #### Parameters `speed` constant 'node.CPU80MHZ' or 'node.CPU160MHZ' #### Returns target CPU frequency (number) #### Example ```lua node.setcpufreq(node.CPU80MHZ) ``` ## node.sleep() Put NodeMCU in light sleep mode to reduce current consumption. * NodeMCU can not enter light sleep mode if wifi is suspended. * All active timers will be suspended and then resumed when NodeMCU wakes from sleep. !!! attention This is disabled by default. Modify `PMSLEEP_ENABLE` in `app/include/user_config.h` to enable it. #### Syntax `node.sleep({wake_pin[, int_type, resume_cb, preserve_mode]})` #### Parameters * `wake_pin` 1-12, pin to attach wake interrupt to. Note that pin 0(GPIO 16) does not support interrupts. * Please refer to the [`GPIO module`](gpio.md) for more info on the pin map. * `int_type` type of interrupt that you would like to wake on. (Optional, Default: `node.INT_LOW`) * valid interrupt modes: * `node.INT_UP` Rising edge * `node.INT_DOWN` Falling edge * `node.INT_BOTH` Both edges * `node.INT_LOW` Low level * `node.INT_HIGH` High level * `resume_cb` Callback to execute when WiFi wakes from suspension. (Optional) * `preserve_mode` preserve current WiFi mode through node sleep. (Optional, Default: true) * If true, Station and StationAP modes will automatically reconnect to previously configured Access Point when NodeMCU resumes. * If false, discard WiFi mode and leave NodeMCU in `wifi.NULL_MODE`. WiFi mode will be restored to original mode on restart. #### Returns - `nil` #### Example ```lua --Put NodeMCU in light sleep mode indefinitely with resume callback and wake interrupt cfg={} cfg.wake_pin=3 cfg.resume_cb=function() print("WiFi resume") end node.sleep(cfg) --Put NodeMCU in light sleep mode with interrupt, resume callback and discard WiFi mode cfg={} cfg.wake_pin=3 --GPIO0 cfg.resume_cb=function() print("WiFi resume") end cfg.preserve_mode=false node.sleep(cfg) ``` #### See also - [`wifi.suspend()`](wifi.md#wifisuspend) - [`wifi.resume()`](wifi.md#wifiresume) - [`node.dsleep()`](#nodedsleep) ## node.stripdebug() Controls the amount of debug information kept during [`node.compile()`](#nodecompile), and allows removal of debug information from already compiled Lua code. Only recommended for advanced users, the NodeMCU defaults are fine for almost all use cases. ####Syntax `node.stripdebug([level[, function]])` #### Parameters - `level` - 1, don't discard debug info - 2, discard Local and Upvalue debug info - 3, discard Local, Upvalue and line-number debug info - `function` a compiled function to be stripped per setfenv except 0 is not permitted. If no arguments are given then the current default setting is returned. If function is omitted, this is the default setting for future compiles. The function argument uses the same rules as for `setfenv()`. #### Returns If invoked without arguments, returns the current level settings. Otherwise, `nil` is returned. #### Example ```lua node.stripdebug(3) node.compile('bigstuff.lua') ``` #### See also [`node.compile()`](#nodecompile) ## node.osprint() Controls whether the debugging output from the Espressif SDK is printed. Note that this is only available if the firmware is build with DEVELOPMENT_TOOLS defined. ####Syntax `node.osprint(enabled)` #### Parameters - `enabled` This is either `true` to enable printing, or `false` to disable it. The default is `false`. #### Returns Nothing #### Example ```lua node.osprint(true) ``` ## node.random() This behaves like math.random except that it uses true random numbers derived from the ESP8266 hardware. It returns uniformly distributed numbers in the required range. It also takes care to get large ranges correct. It can be called in three ways. Without arguments in the floating point build of NodeMCU, it returns a random real number with uniform distribution in the interval [0,1). When called with only one argument, an integer n, it returns an integer random number x such that 1 <= x <= n. For instance, you can simulate the result of a die with random(6). Finally, random can be called with two integer arguments, l and u, to get a pseudo-random integer x such that l <= x <= u. #### Syntax `node.random()` `node.random(n)` `node.random(l, u)` #### Parameters - `n` the number of distinct integer values that can be returned -- in the (inclusive) range 1 .. `n` - `l` the lower bound of the range - `u` the upper bound of the range #### Returns The random number in the appropriate range. Note that the zero argument form will always return 0 in the integer build. #### Example ```lua print ("I rolled a", node.random(6)) ``` # node.egc module ## node.egc.setmode() Sets the Emergency Garbage Collector mode. [The EGC whitepaper](http://www.eluaproject.net/doc/v0.9/en_elua_egc.html) provides more detailed information on the EGC. ####Syntax `node.egc.setmode(mode, [param])` #### Parameters - `mode` - `node.egc.NOT_ACTIVE` EGC inactive, no collection cycle will be forced in low memory situations - `node.egc.ON_ALLOC_FAILURE` Try to allocate a new block of memory, and run the garbage collector if the allocation fails. If the allocation fails even after running the garbage collector, the allocator will return with error. - `node.egc.ON_MEM_LIMIT` Run the garbage collector when the memory used by the Lua script goes beyond an upper `limit`. If the upper limit can't be satisfied even after running the garbage collector, the allocator will return with error. If the given limit is negative, it is interpreted as the desired amount of heap which should be left available. Whenever the free heap (as reported by `node.heap()` falls below the requested limit, the garbage collector will be run. - `node.egc.ALWAYS` Run the garbage collector before each memory allocation. If the allocation fails even after running the garbage collector, the allocator will return with error. This mode is very efficient with regards to memory savings, but it's also the slowest. - `level` in the case of `node.egc.ON_MEM_LIMIT`, this specifies the memory limit. #### Returns `nil` #### Example `node.egc.setmode(node.egc.ALWAYS, 4096) -- This is the default setting at startup.` `node.egc.setmode(node.egc.ON_ALLOC_FAILURE) -- This is the fastest activeEGC mode.` `node.egc.setmode(node.egc.ON_MEM_LIMIT, 30720) -- Only allow the Lua runtime to allocate at most 30k, collect garbage if limit is about to be hit` `node.egc.setmode(node.egc.ON_MEM_LIMIT, -6144) -- Try to keep at least 6k heap available for non-Lua use (e.g. network buffers)` ## node.egc.meminfo() Returns memory usage information for the Lua runtime. ####Syntax `total_allocated, estimated_used = node.egc.meminfo()` #### Parameters None. #### Returns - `total_allocated` The total number of bytes allocated by the Lua runtime. This is the number which is relevant when using the `node.egc.ON_MEM_LIMIT` option with positive limit values. - `estimated_used` This value shows the estimated usage of the allocated memory. # node.task module ## node.task.post() Enable a Lua callback or task to post another task request. Note that as per the example multiple tasks can be posted in any task, but the highest priority is always delivered first. If the task queue is full then a queue full error is raised. ####Syntax `node.task.post([task_priority], function)` #### Parameters - `task_priority` (optional) - `node.task.LOW_PRIORITY` = 0 - `node.task.MEDIUM_PRIORITY` = 1 - `node.task.HIGH_PRIORITY` = 2 - `function` a callback function to be executed when the task is run. If the priority is omitted then this defaults to `node.task.MEDIUM_PRIORITY` #### Returns `nil` #### Example ```lua for i = node.task.LOW_PRIORITY, node.task.HIGH_PRIORITY do node.task.post(i,function(p2) print("priority is "..p2) end) end ``` prints ``` priority is 2 priority is 1 priority is 0 ```