Arduino library for controlling PISO shift register. PISO stands for Parallel In Serial Out. This type of shift register is used to read multiple digital inputs using only a few microcontroller pins.

The libraly relies on timestamps to manage timing of reading and clock signals. This way, it does not block the main program loop, allowing other parts of the code to run concurrently.

Library further provides methods for setting delays between reading or adjusting frequency of clock signal. The real time intervals may depend on computational complexity of the main thread.

The library provides a class PISORegister with methods for initializing and reading data from the shift register.

To initialize the reading process, Init() method must be called. This method initializes the pins connected to shift register and sets the polarity of signals, as well as number of register inputs. Required inputs:

• pinNum Number of register inputs (max 64)
• clkPin Pin used for clock signal
• ldPin Pin used for asynchronous load signal
• qhPin Input from shift register
• clkPol Polarity of clock edge - true for rising edge, false for falling edge
• ldPol Logic level of asynchronous loading - false for 0, true for 1
• inputLogic Type of input logic (true for normal, false for inverse)

• SetFrequency() - Set frequency of clock signal
• SetReadDelay() - Set delay between reading inputs
• SetGlitchPrevention() - Set number of consistent readings before updating input data
• SetLdClkPulseDelay() - If delay is not 0, generates additional clock pulse during loading phase. Some registers require this to load inputs. This is the delay between loading signal edge and clock pulse signal edge during loading phase.

For continuous reading, call ReadData() method in main program loop.

To improve input reliability, SetGlitchPrevention() method can be used. Using this option, input data are updated only if the input has been constant for certain number of reading.

To obtain data from specific input, use GetInput() method. This input corresponds to the input number on the shift register (0 to pinNum-1).

To obtain data from all inputs as a single integer, use GetAllInputData() method.