This module provides simple performance measurement for an application.
It samples the program counter roughly every 50 microseconds and builds
This module provides simple performance measurement for an application. It samples the program counter roughly every 50 microseconds and builds a histogram of the values that it finds. Since there is only a small amount
a histogram of the values that it finds. Since there is only a small amount
of memory to store the histogram, the user can specify which area of code is of interest. The default is the entire flash which contains code. Once the hotspots are identified, then the run can then be repeated with different areas and at different resolutions to get as much information as required.
of memory to store the histogram, the user can specify which area of code
is of interest. The default is the enitre flash which contains code. Once the hotspots are
identified, then the run can then be repeated with different areas and at different
resolutions to get as much information as required.
This module can read the state of cheap rotary encoder switches. These are available at
all the standard places for a dollar or two. They are five pin devices where three are used
for a gray code encoder for rotation, and two are used for the push switch. These switches
are commonly used in car audio systems.
These switches do not have absolute positioning, but only encode the number of positions
This module can read the state of cheap rotary encoder switches. These are available at all the standard places for a dollar or two. They are five pin devices where three are used for a gray code encoder for rotation, and two are used for the push switch. These switches are commonly used in car audio systems.
rotated clockwise / anticlockwise. To make use of this module, connect the common pin on the quadrature
encoder to ground and the A and B phases to the nodemcu. One pin of the push switch should
These switches do not have absolute positioning, but only encode the number of positions rotated clockwise / anti-clockwise. To make use of this module, connect the common pin on the quadrature encoder to ground and the A and B phases to the NodeMCU. One pin of the push switch should also be grounded and the other pin connected to the NodeMCU.
also be grounded and the other pin connected to the nodemcu.
The rtcfifo module implements a first-in,first-out storage intended for sensor readings. As the name suggests, it is backed by the [RTC](https://en.wikipedia.org/wiki/Real-time_clock) user memory and as such survives deep sleep cycles. Conceptually it can be thought of as a cyclic array of `{ timestamp, name, value }` tuples. Internally it uses a space-optimized storage format to allow the greatest number of samples to be kept. This comes with several trade-offs, and as such is not a one-solution-fits-all. Notably:
The rtcfifo module implements a first-in,first-out storage intended for sensor readings. As the name suggests, it is backed by the [RTC](https://en.wikipedia.org/wiki/Real-time_clock) user memory and as such survives deep sleep cycles. Conceptually it can be thought of as a cyclic array of `{ timestamp, name, value }` tuples. Internally it uses a space-optimized storage format to allow the greatest number of samples to be kept. This comes with several trade-offs, and as such is not a one-solution-fits-all. Notably:
The rtcmem module provides basic access to the [RTC](https://en.wikipedia.org/wiki/Real-time_clock)(Real Time Clock) memory.
The rtcmem module provides basic access to the [RTC](https://en.wikipedia.org/wiki/Real-time_clock)(Real Time Clock) memory.
The RTC in the ESP8266 contains memory registers which survive a deep sleep, making them highly useful for keeping state across sleep cycles. Some of this memory is reserved for system use, but 128 slots (each 32bit wide) are available for application use. This module provides read and write access to these.
The RTC in the ESP8266 contains memory registers which survive a deep sleep, making them highly useful for keeping state across sleep cycles. Some of this memory is reserved for system use, but 128 slots (each 32bit wide) are available for application use. This module provides read and write access to these.
The rtctime module provides advanced timekeeping support for NodeMCU, including keeping time across deep sleep cycles (provided [`rtctime.dsleep()`](#rtctimedsleep) is used instead of [`node.dsleep()`](node.md#nodedsleep)). This can be used to significantly extend battery life on battery powered sensor nodes, as it is no longer necessary to fire up the RF module each wake-up in order to obtain an accurate timestamp.
The rtctime module provides advanced timekeeping support for NodeMCU, including keeping time across deep sleep cycles (provided [`rtctime.dsleep()`](#rtctimedsleep) is used instead of [`node.dsleep()`](node.md#nodedsleep)). This can be used to significantly extend battery life on battery powered sensor nodes, as it is no longer necessary to fire up the RF module each wake-up in order to obtain an accurate timestamp.
This module provides access to the [sigma-delta](https://en.wikipedia.org/wiki/Delta-sigma_modulation) component. It's a hardware signal generator that can be routed to any of the GPIOs except pin 0.
The signal generation is controlled by the [`setprescale()`](#sigma_deltasetprescale) and [`settarget()`](#sigma_deltasettarget) functions.
The signal generation is controlled by the [`setprescale()`](#sigma_deltasetprescale) and [`settarget()`](#sigma_deltasettarget) functions.
The SNTP module implements a [Simple Network Time Procotol](https://en.wikipedia.org/wiki/Network_Time_Protocol#SNTP) client. This includes support for the "anycast" [NTP](https://en.wikipedia.org/wiki/Network_Time_Protocol) mode where, if supported by the NTP server(s) in your network, it is not necessary to even know the IP address of the NTP server.
The SNTP module implements a [Simple Network Time Procotol](https://en.wikipedia.org/wiki/Network_Time_Protocol#SNTP) client. This includes support for the "anycast" [NTP](https://en.wikipedia.org/wiki/Network_Time_Protocol) mode where, if supported by the NTP server(s) in your network, it is not necessary to even know the IP address of the NTP server.
values into a struct-like string; and `struct.unpack`, which unpacks
multiple Lua values from a given struct-like string.
This module offers basic facilities to convert Lua values to and from C structs. Its main functions are `struct.pack`, which packs multiple Lua values into a struct-like string; and `struct.unpack`, which unpacks multiple Lua values from a given struct-like string.
The first argument to both functions is a *format string*, which
The first argument to both functions is a *format string*, which describes the layout of the structure. The format string is a sequence of conversion elements, which respect the current endianess and the current alignment requirements. Initially, the current endianess is the machine's native endianness and the current alignment requirement is 1 (meaning no alignment at all). You can change these settings with appropriate directives in the format string.
describes the layout of the structure. The format string is a sequence
of conversion elements, which respect the current endianess and the
Note that the float and double conversions are only available with a floating point NodeMCU build.
current alignment requirements. Initially, the current endianess is the
machine's native endianness and the current alignment requirement is 1
(meaning no alignment at all). You can change these settings with
appropriate directives in the format string.
Note that the float and double conversions are only available with
U8glib is a graphics library developed at [olikraus/u8glib](https://github.com/olikraus/u8glib) with support for many different displays. The NodeMCU firmware supports a subset of these.
U8glib is a graphics library developed at [olikraus/u8glib](https://github.com/olikraus/u8glib) with support for many different displays. The NodeMCU firmware supports a subset of these.
The [UART](https://en.wikipedia.org/wiki/Universal_asynchronous_receiver/transmitter)(Universal asynchronous receiver/transmitter) module allows configuration of and communication over the UART serial port.
The [UART](https://en.wikipedia.org/wiki/Universal_asynchronous_receiver/transmitter)(Universal asynchronous receiver/transmitter) module allows configuration of and communication over the UART serial port.
Ucglib is a graphics library developed at [olikraus/ucglib](https://github.com/olikraus/ucglib) with support for color TFT displays. The NodeMCU firmware supports a subset of these:
Ucglib is a graphics library developed at [olikraus/ucglib](https://github.com/olikraus/ucglib) with support for color TFT displays. The NodeMCU firmware supports a subset of these: