Digital In

Introduction

The Digital In 3-Wire device allows the V5 Brain to read a digital signal from an external source, such as a switch or sensor. It detects whether the input line is high (receiving 5V) or low (receiving 0V). This can be used to determine on/off states or trigger events in a project.

This page uses dig_in as the example Digital In device name. Replace it with your own configured name as needed.

Below is a list of available methods:

• value – Returns an integer indicating whether the received signal is high or low.

• high – Registers a function to be called whenever the Digital In device sends a high signal (approximately 5V).

• low – Registers a function to be called whenever the Digital In device sends a low signal (approximately 0V).

Constructor – Manually initialize and configure a Digital In device.

• DigitalIn – Create a Digital In device.

value

value returns an integer indicating whether the received signal is a high or low.

• 1 – The Digital In port is receiving a high signal (approximately 5V).

• 0 – The Digital In port is receiving a low signal (approximately 0V).

Usage:
dig_in.value()

Parameters	Description
	This method has no parameters.

high

high registers a function to be called whenever the Digital In device sends a high signal (approximately 5V).

Usage:
dig_in.high(callback, arg)

Parameters	Description
callback	A previously defined function that executes when a high signal is received.
arg	Optional. A tuple containing arguments to pass to the callback function. See Functions with Parameters for more information.

def my_function():
  brain.screen.print("High")

# Call my_function whenever dig_in is high
dig_in.high(my_function)

low

low registers a function to be called whenever the Digital In device sends a low signal (approximately 0V).

Usage:
dig_in.low(callback, arg)

Parameters	Description
callback	A previously defined function that executes when a low signal is received.
arg	Optional. A tuple containing arguments to pass to the callback function. See Functions with Parameters for more information.

def my_function():
  brain.screen.print("Low")

# Call my_function whenever dig_in is low
dig_in.low(my_function)

Constructor

Constructors are used to manually create DigitalIn objects, which are necessary for configuring a Digital In device outside of VEXcode.

DigitalIn

DigitalIn creates a Digital In device.

Usage:
DigitalIn(port)

Parameter	Description
port	The 3-Wire Port that the Digital In device is connected to: On the V5 Brain – brain.three_wire_port.x where x is the number of the port. On a 3-Wire Expander – expander.a where expander is the name of the expander instance.

# Create a Digital In device in Port A
dig_in = DigitalIn(brain.three_wire_port.a)