26 KiB
node Module
Since | Origin / Contributor | Maintainer | Source |
---|---|---|---|
2014-12-22 | Zeroday | TerryE | 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, EPC1, EPC2, EPC3, EXCVADDR, and DEPC.
Syntax
node.bootreason()
Parameters
none
Returns
rawcode, reason [, exccause, epc1, epc2, epc3, excvaddr, depc ]
Example
_, 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
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()
. "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) ornil
, sleep time in micro second. Ifus == 0
, it will sleep forever. Ifus == nil
, will not set sleep time. -
option
number (integer) ornil
. Ifnil
, 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) ornil
. 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
--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
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
node.dsleep(node.dsleepMax())
See also
node.flashid()
Returns the flash chip ID.
Syntax
node.flashid()
Parameters
none
Returns
flash ID (number)
node.flashindex()
Deprecated synonym for node.LFS.get()
to return an LFS function reference.
Note that this returns nil
if the function does not exist in LFS.
node.flashreload()
Deprecated synonym for node.LFS.reload()
to reload LFS (Lua Flash Store) with the named flash image provided.
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
do
local cpuFreq = node.getcpufreq()
print("The current CPU frequency is " .. cpuFreq .. " MHz")
end
node.getpartitiontable()
Get the current LFS and SPIFFS partition information.
Syntax
node.getpartitiontable()
Parameters
none
Returns
An array containing entries for lfs_addr
, lfs_size
, spiffs_addr
and spiffs_size
. The address values are offsets relative to the start of the Flash memory.
Example
print("The LFS size is " .. node.getpartitiontable().lfs_size)
See also
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 information about hardware, software version and build configuration.
Syntax
node.info([group])
Parameters
group
A designator for a group of properties. May be one of "hw"
, "sw_version"
, "build_config"
. It is currently optional; if omitted the legacy structure is returned. However, not providing any value is deprecated.
Returns
If a group
is given the return value will be a table containing the following elements:
-
for
group
="hw"
chip_id
(number)flash_id
(number)flash_size
(number)flash_mode
(number) 0 = QIO, 1 = QOUT, 2 = DIO, 15 = DOUT.flash_speed
(number)
-
for
group
="lfs"
lfs_base
(number) Flash offset of selected LFS regionlfs_mapped
(number) Mapped memory address of selected LFS regionlfs_size
(number) size of selected LFS regionlfs_used
(number) actual size used by current LFS image
-
for
group
="sw_version"
git_branch
(string)git_commit_id
(string)git_release
(string) release name +additional commits e.g. "2.0.0-master_20170202 +403"git_commit_dts
(string) commit timestamp in an ordering format. e.g. "201908111200"node_version_major
(number)node_version_minor
(number)node_version_revision
(number)
-
for
group
="build_config"
ssl
(boolean)lfs_size
(number) as defined at build timemodules
(string) comma separated listnumber_type
(string)integer
orfloat
!!! attention
Not providing a `group` is deprecated and support for that will be removed in one of the next releases.
- for
group
=nil
majorVer
(number)minorVer
(number)devVer
(number)chipid
(number)flashid
(number)flashsize
(number)flashmode
(number)flashspeed
(number)
Example
majorVer, minorVer, devVer, chipid, flashid, flashsize, flashmode, flashspeed = node.info()
print("NodeMCU "..majorVer.."."..minorVer.."."..devVer)
for k,v in pairs(node.info("build_config")) do
print (k,v)
end
print(node.info("sw_version").git_release)
node.input()
Submits a string to the Lua interpreter. Similar to pcall(loadstring(str))
, but without the single-line limitation. Note that the Line interpreter only actions complete Lua chunks. A Lue Lua chunk must comprise one or more complete '\n'
terminaed lines that form a complete compilation unit.
Syntax
node.input(str)
Parameters
str
Lua chunk
Returns
nil
Example
sk:on("receive", function(conn, payload) node.input(payload) end)
See the telnet/telnet.lua
in lua_examples
for a more comprehensive example.
See also
node.LFS
Sub-table containing the API for Lua Flash Store(LFS) access. Programmers might prefer to map this to a global or local variable for convenience for example:
local LFS = node.LFS
This table contains the following methods and properties:
Property/Method | Description |
---|---|
config |
A synonym for node.info('lfs') . Returns the properties lfs_base , lfs_mapped , lfs_size , lfs_used . |
get() |
See node.LFS.get(). |
list() |
See node.LFS.list(). |
reload() |
See node.LFS.reload(). |
time |
Returns the Unix timestamp at time of image creation. |
node.LFS.get()
Returns the function reference for a function in LFS.
Note that unused node.LFS
properties map onto the equialent get()
call so for example: node.LFS.mySub1
is a synonym for node.LFS.get('mySub1')
.
Syntax
node.LFS.get(modulename)
Parameters
modulename
The name of the module to be loaded.
Returns
- If the LFS is loaded and the
modulename
is a string that is the name of a valid module in the LFS, then the function is returned in the same way theload()
and the other Lua load functions do - Otherwise
nil
is returned.
node.LFS.list()
List the modules in LFS.
Returns
- If no LFS image IS LOADED then
nil
is returned. - Otherwise an sorted array of the name of modules in LFS is returned.
node.LFS.reload()
Reload LFS with the flash image provided. Flash images can be generated on the host machine using the luac.cross
command.
Syntax
node.LFS.reload(imageName)
Parameters
imageName
The name of a image file in the filesystem to be loaded into the LFS.
Returns
- In the case when the
imagename
is a valid LFS image, this is expanded and loaded into flash, and the ESP is then immediately rebooted, so control is not returned to the calling Lua application in the case of a successful reload. - The reload process internally makes multiple passes through the LFS image file. The first pass validates the file and header formats and detects many errors. If any is detected then an error string is returned.
node.output()
Redirects the Lua interpreter to a stdout
pipe when a CB function is specified (See pipe
module) and resets output to normal otherwise. Optionally also prints to the serial console.
Syntax
node.output(function(pipe), serial_debug)
Parameters
output_fn(pipe)
a function accept every output as str, and can send the output to a socket (or maybe a file). Note that this function must conform to the fules for a pipe reader callback.serial_debug
1 output also show in serial. 0: no serial output.
Returns
nil
Example
See the telnet/telnet.lua
in lua_examples
for a more comprehensive example of its use.
See also
node.readvdd33() --deprecated
Moved to adc.readvdd33()
.
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
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
node.setcpufreq(node.CPU80MHZ)
node.setpartitiontable()
Sets the current LFS and / or SPIFFS partition information.
Syntax
node.setpartitiontable(partition_info)
!!! note This function is typically only used once during initial provisioning after first flashing the firmware. It does some consistency checks to validate the specified parameters, and it then reboots the ESP module to load the new partition table. If the LFS or SPIFFS regions have changed then you will need to reload LFS, reformat the SPIFSS and reload its contents.
Parameters
An array containing one or more of the following enties. The address values are byte offsets relative to the start of the Flash memory. The size values are in bytes. Note that these parameters must be a multiple of 8Kb to align to Flash page boundaries.
lfs_addr
. The base address of the LFS region.lfs_size
. The size of the LFS region.spiffs_addr
. The base address of the SPIFFS region.spiffs_size
. The size of the SPIFFS region.
Returns
Not applicable. The ESP module will be rebooted for a valid new set, or a Lua error will be thown if inconsistencies are detected.
Example
node.setpartitiontable{lfs_size = 0x20000, spiffs_addr = 0x120000, spiffs_size = 0x20000}
See also
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
for more info on the pin map.
- Please refer to the
int_type
type of interrupt that you would like to wake on. (Optional, Default:node.INT_LOW
)- valid interrupt modes:
node.INT_UP
Rising edgenode.INT_DOWN
Falling edgenode.INT_BOTH
Both edgesnode.INT_LOW
Low levelnode.INT_HIGH
High level
- valid interrupt modes:
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
--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
node.startupcommand()
Overrides the default startup action on processor restart, preplacing the executing init.lua
if it exists. This is now deprecated in favor of node.startup({command="the command"})
.
Syntax
node.startupcommand(string)
Parameters
string
prefixed with either@
, the remaining string is a filename to be executed.=
, the remaining string is Lua chunk to be compiled and executed.
Returns
`status` this is `false` if write to the Reboot Config Record fails. Note that no attempt is made to parse or validate the string. If the command is invalid or the file missing then this will be reported on the next restart.
Example
node.startupcommand("@myappstart.lc") -- Execute the compiled file myappstart.lc on startup
-- Execute the LFS routine init() in preference to init.lua
node.startupcommand("=if LFS.init then LFS.init() else dofile('init.lua') end")
node.startupcounts()
Query the performance of system startup.
!!! Important
This function is only available if the firmware is built with `PLATFORM_STARTUP_COUNT` defined. This would normally be done by uncommenting the `#define PLATFORM_STARTUP_COUNT` line in `app/include/user_config.h`.
Syntax
node.startupcounts([marker])
Parameters
marker
If present, this will add another entry into the startup counts
Returns
An array of tables which indicate how many CPU cycles had been consumed at each step of platform boot.
Example
=sjson.encode(node.startupcounts())
This might generate the output (formatted for readability):
[
{"ccount":3774328,"name":"user_pre_init","line":124},
{"ccount":3842297,"name":"user_pre_init","line":180},
{"ccount":9849869,"name":"user_init","line":327},
{"ccount":10008843,"name":"nodemcu_init","line":293},
{"ccount":10295779,"name":"pmain","line":234},
{"ccount":11378766,"name":"pmain","line":256},
{"ccount":11565912,"name":"pmain","line":260},
{"ccount":12158242,"name":"node_startup_counts","line":1},
{"ccount":12425790,"name":"myspiffs_mount","line":126},
{"ccount":12741862,"name":"myspiffs_mount","line":148},
{"ccount":13983567,"name":"pmain","line":265}
]
The crucial entry is the one for node_startup_counts
which is when the application had started running. This was on a Wemos D1 Mini with flash running at 80MHz. The startup options were all turned on.
Note that the clock speed changes in user_pre_init
to 160MHz. The total time was (approximately): 3.8 / 80 + (12 - 3.8) / 160 = 98ms
. With startup options of 0, the time is 166ms. These times may be slightly optimistic as the clock is only 52MHz for a time during boot.
node.startup()
Get/set options that control the startup process. This interface will grow over time.
Syntax
node.startup([{table}])
Parameters
If the argument is omitted, then no change is made to the current set of startup options. If the argument is the empty table {}
then all options are
reset to their default values.
table
one or more options:banner
- set to true or false to indicate whether the startup banner should be displayed or not. (default: true)frequency
- set to node.CPU80MHZ or node.CPU160MHZ to indicate the initial CPU speed. (default: node.CPU80MHZ)delay_mount
- set to true or false to indicate whether the SPIFFS filesystem mount is delayed until it is first needed or not. (default: false)command
- set to a string which is the initial command that is run. This is the same string as in thenode.startupcommand
.
Returns
table
This is the complete set of options in the state that will take effect on the next boot. Note that the command
key may be missing -- in which
case the default value will be used.
Example
node.startup({banner=false, frequency=node.CPU160MHZ}) -- Prevent printing the banner and run at 160MHz
node.stripdebug()
Controls the amount of debug information kept during node.compile()
, 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
node.stripdebug(3)
node.compile('bigstuff.lua')
See also
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 eithertrue
to enable printing, orfalse
to disable it. The default isfalse
.
Returns
Nothing
Example
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 rangeu
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
print ("I rolled a", node.random(6))
node.egc module
node.egc.setmode()
Sets the Emergency Garbage Collector mode. The EGC whitepaper 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 situationsnode.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 upperlimit
. 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 bynode.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 ofnode.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 thenode.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
= 0node.task.MEDIUM_PRIORITY
= 1node.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
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