the controllers that require direct access to the Arduinos digital pins. option is a Teensy extension which is not present on the official Arduino. When the button is pressed the digital input pin 2 reads a change in value and triggers the red LED (pin 4) to turn off and yellow LED (pin 3) to turn on. Note that the Arduino output pins 9 and 3 are both PWM-enabled. A lot of Dev Boards like Arduino, STM, ChipKit etc (Even micro computers like Raspberry Pi) have a limited number of Digital input and output pins, which is a serious problem for the makers while creating them projects, especially when the Dev Board should be connected to an important number of peripheric (Exemple: the 5x5x5 LED Cube where you need to control more than. When your sketch begins running, all digital pins default to input mode. PinMode(4, OUTPUT) // set the red LED pin to be an outputДigitalWrite(3, HIGH) // turn on the yellow LEDДigitalWrite(4, LOW) // turn off the red LEDДigitalWrite(3, LOW) // turn off the yellow LEDДigitalWrite(4, HIGH) // turn on the red LEDД«y default the red LED is on. PinMode(3, OUTPUT) // set the yellow LED pin to be an output The connection will be as follows: Power supply to 12 V. PinMode(2, INPUT) // set the pushbutton pin to be an input We will also use a second microcontroller board to make use of two additional digital inputs. Seven-segment displays are widely used in digital clocks, electronic meters, basic calculatorsSeven Segment Display Pin Configurations. PCF8574 i2c digital I/O expander PCF8575 i2c 16 bit digital I/O expander. A switch connected to a digital IO pin is used to indicate when to trigger the LEDs. But in complex circuits, we may have a lack of Arduino ports due to the need. The idea for this lab was to control an LED turning on and off through programming. For this first lab I made use of digital IO (inputs and outputs) which are capable of reading the values on and off. This week I went hands on with an Arduino Nano 33 IoT and setup circuits with logic running through the Arduino.

Arduino digital input