IoT

At first glance, with the Arduino UNO microcontroller (μcontroller) it can be concluded that the number of digital pins is insufficient for a more serious project. The Arduino Mega offers 54 digital pins, so you can consider purchasing such a microcontroller. Another solution that allows you to increase the number of pins is to use shift registers. In this case, we are talking about the shift register 74HC595. How this is achieved, how a scroll register works and how to use it with an Arduino UNO controller is the topic of this video tutorial and text.

The seven-segment display (single-digit) is one of the electronic components intended for displaying numerical values (integers from 0 to 9). The designation of the component that will be used in the exercise is 5161AS.

What are segments? The seven-segment display consists of 8 LED elements, 7 are used to represent numerical values and 1 LED element is used to represent a decimal point. The segments are arranged in the shape of the number “8”. By including precisely defined segments, it is possible to display any number from 0 to 9.

The aim of this project is to get acquainted with the way of using the potentiometer, the operation of analog inputs and reading the values from the sensors (in this case the role of the sensor is played by the potentiometer). A theoretical explanation is given at the beginning of the video. In the following, we will see what it looks like when we read the voltage that we control with a potentiometer from the analog input of the Arduino, and how we use that voltage value to control the light intensity of the LED.

When using a microcontroller, when the pin we use as an input is not set to “HIGH” or “LOW” state, but its state “floats” between these two values, we say that it is in a state of high impedance. This is a condition that we definitely want to avoid because it leads to irregularities (unpredictability) in work and that is why we introduce a concept like“pull-up”and“pull-down”resistors. These are not special types of resistors, but resistors that allow us to maintain the desired state of the logic circuit regardless of the conditions. Arduino pin is connected via this resistor to a constant value, either to the + 5V power supply or to the GND (ground). In the first case it is a “pull-up”, while in the second we are talking about a “pull-down” resistor.