GY-63_MS5611/libraries/PinInGroup
2021-11-12 15:01:35 +01:00
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examples/testPinInGroup 0.1.5 PinInGroup 2021-11-12 15:01:35 +01:00
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.arduino-ci.yml 0.1.5 PinInGroup 2021-11-12 15:01:35 +01:00
keywords.txt 0.1.5 PinInGroup 2021-11-12 15:01:35 +01:00
library.json 0.1.5 PinInGroup 2021-11-12 15:01:35 +01:00
library.properties 0.1.5 PinInGroup 2021-11-12 15:01:35 +01:00
LICENSE 2021-01-29 2021-01-29 12:31:58 +01:00
PinInGroup.cpp 0.1.5 PinInGroup 2021-11-12 15:01:35 +01:00
PinInGroup.h 0.1.5 PinInGroup 2021-11-12 15:01:35 +01:00
README.md 0.1.5 PinInGroup 2021-11-12 15:01:35 +01:00

Arduino CI Arduino-lint JSON check License: MIT GitHub release

PinInGroup

Arduino library to read a group of up to 16 input pins in one command.

Description

A PinInGroup holds a number of input pins that can be read by means of a single read() command. The PinInGroup makes it easier to work with a number of inputs that act as a logical unit. Think of reading a parallel bus or read 4 lines from a matrix keyboard, or an array of switches.

One of the interesting possibilities of the pinInGroup is to add a single pin multiple times. That allows one to read a pin e.g. in a burst of 8.

Another application of adding a pin twice could be reading a pin as first and as last of a group. This allows you to check that state of e.g. a parallel bus has not changed during read (or changed an even number :).

Default PININGROUP_MAXSIZE = 16.

Performance

The PinInGroup is not more efficient as reading the pins in a loop yourself. However it is less programming and can give clearer code.

Note that the pins are not read at the same microsecond. A small time is needed to go through all pins. This is platform, group size and pin state dependent.

Interface

Constructor

  • PinInGroup() Constructor.

Administration

  • void clear() sets the size to zero so one can repopulate.
  • uint8_t add(uint8_t size, uint8_t * pinArray, uint8_t mode) adds a predefined array of pins to the group. Returns the number of pins added.
  • uint8_t add(uint8_t pin, uint8_t mode) adds a single pin to the group. Returns the number of pins added (1 or 0). Mode can be INPUT(default) or INPUT_PULLUP.
  • uint8_t getPin(uint8_t index) index = 0..15; returns the pin at slot index or 255 (0xFF) when out of range.
  • uint8_t getIndex(uint8_t pin) returns the (first) index of the slot with pin number. 255 (0xFF) if not found.
  • uint8_t isInGroup(uint8_t pin) returns how often a pin is added to a group. Can be more than once.
  • uint8_t size() how many slots are used.
  • uint8_t getMaxSize() how many slots are there in total.
  • uint8_t available() how many slots are free.

Read

  • uint16_t read() reads a 16 bits unsigned int from max 16 pins. Every bit represents an input value. Note that the bits are in LSB order of the adding.
  • uint16_t read(uint8_t index) index = 0..size-1. Reads the single pin at index from the group. Returns 0 or 1 if OK and 0xFFFF when index >= size.

Operation

See examples.

Future

  • Optimize the low level reading e.g. reading registers only once.
    • Hold register and bit info per pin.
    • Especially for AVR this could be interesting performance wise.
  • Create an analogPinGroup and a PWMGroup
  • extend to 32 bits / pins. class hierarchy. 8, 24 ?
  • Allocate dynamic memory (0.2.0)
    • fragmentation?
    • would be memory efficient.
  • clear() => reset() or clearGroup() ???
  • do we need yield() somewhere?

These ideas will be explored when time permits or needs arise.