Digital inputs and outputs

Digital signals

Binary Digits

A digital signal is a type of signal that represents data as discrete values, using binary digits (bits).

In digital signals, the information is encoded as a sequence of binary numbers, where each bit can have one of two possible states: ‘0’ or ‘1’.

Digital signals are the primitive signals of microcontrollers. All the internal data transit as ‘0’ or ‘1’ between the different main organs: memories, processing units…

Digital carrier signals

In digital systems, bits are typically carried using electronic signals. These signals can be represented by different physical phenomena such as voltage levels in electrical circuits, light pulses in optical fibers, or magnetic polarities in magnetic storage devices.

In STM32 microcontrollers on Nucleo boards, two different voltage levels are used:

• 0V for logical ‘0’

• 3.3V for logical ‘1’

Digital Ouputs

Digital outputs are often used in microcontroller-based systems for interfacing with the external world.

They are commonly used in electronic systems to control devices such as motors, lights, or relays, where the output state determines whether the device is on or off, open or closed, etc.

Declare an output

Digital ouput are described by the DigitalOut class from the mbed.h library.

DigitalOut var_name(PIN_NAME);

As a bridge with the external world, this instruction required a valid PIN_NAME.

Update an output

Digital Inputs

Warning

Voltage between 0 and 3.3V !