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Purpose

Get the value of a Digital Input (DI) of the board.

When to use

Whenever you need to use the state of a DI.

Where to use

Most probably in the void loop() part of your .ino file, since we’d usually want to actively monitor the value.

Info

Click here to learn more on the DIOs of the 9880 board.

Note

This function requires the use of the following CrcLib functions at some point of your .ino file in order to work properly:

Returns

This function returns state of the DI mentioned as the function’s argument as an unsigned char type. The value returned will be either one of these two possible values:

  • HIGH, if voltage is applied to the SIG pin of the digital port.

  • LOW, if no voltage is applied to the SIG pin of the digital port.

Main prototype and parameters

static void unsigned char Crc::CrcLib::SetDigitalPinModeGetDigitalInput(unsigned char pin, unsigned char mode)

The following parameters must be passed to the function for it to work properly:

  • pin: The name of the digital pin you want to set. Must be of the type unsigned char.mode: The mode you want to set the pin to. read the state of. Must be of the type unsigned char. Needs to be one of the following:

  • INPUT, if you are using the digital pin as as input.

    • OUTPUT, if you are using the digital pin as as output

    .

Overloads

This function does not have any overloads. It can only be used as described by the main prototype.

Examples

code
Expand
title#1: We want to connect a digital sensor, like a count the number of time a Normally Open limit switch, to connected between the DIO Port 5. We want to connect a small light or a relay control signal, to DIO Port 9.
port 5, has been pressed since the start of the code execution.
Code Block
languagecpp
More on this function
 Info
Why does this function return HIGH/ LOW, instead of 
 TRUE 
 true / 
 FALSE?
 false?
The Arduino environment, when speaking of voltage, uses the constant HIGH to represent its presence and LOW to represent its absence. In electronics, a voltage presence (or when is is greater than a certain value) is usually represented by true, while an absence of voltage (or when it is lower than a certain value) is usually represented by false. Read this page to learn more on the meaning of true and false in a programming context.