Components Required

The following component needed for this tutorial.

• Arduino Uno
• 2 Common anode 7 segment display
• 74hc595 shift register
• 220-ohm resistor
• Breadboard
• Some jumper wire
  

Pin Configuration

Fig: Common anode 7 segment display pinout

Fig: 74hc595 pinout

Circuit Schematic

The following figure shows the 7 segment display multiplexing with 74hc595 shift register using Arduino.

Fig: 7 Segment display multiplexing

Circuit Description

The shift register has 16 pins in which 7 output pins will connect with 7 segment LEDs pin. The shift register Vcc pin 16 and MR pin 10 will connect to +5V.  The ground pin 8 and output enable pin 13 will goes to ground. Next, shift register clock, latch, and data pins are gradually 11,12 and 14 will connect to Arduino digital pin 2, 3 and 4 respectively. Seven segment display common pins will connect to Arduino digital pin 6 and 7 through the 220-ohm series resistor.   

7 segment display ----------------- 74hc595 shift register

Pin_7(Seg_a)    ---------------          Pin_15(Q_A)

Pin_6(Seg_b)    ---------------          Pin_1(Q_A)

Pin_4(Seg_c)     ---------------          Pin_2(Q_A)

Pin_2(Seg_d)     ---------------          Pin_3(Q_A)

Pin_1(Seg_e)     ---------------          Pin_4(Q_A)

Pin_10(Seg_f)     --------------         Pin_5(Q_A)

Pin_9(Seg_g)     --------------          Pin_6(Q_A)

Source Code

Overview

In this Arduino tutorial, we will learn how to interface common anode and cathode 7 segment display with Arduino. 7 segment display is most common and popular display to show the number in the digital electronics and embedded system. It can be displayed in 0 to 9 decimal number.  They are easy to use and cheap. 7 Segment displays are two types of display called common cathode (common negative) and common anode (common positive).

Components Required

• Arduino Uno
• 7 Segment Display Common Anode
• 7 Segment Display Common Cathode
• 220-ohm resistor
• Breadboard
• Some jumper wire

7 Segment Pinout

Fig: 7 segments display pinout

Circuit Schematic

The following figure shows Arduino and the common cathode 7 segment display interfacing.

Fig: 7 segments common cathode display interfacing

The following figure shows Arduino and the common anode 7 segment display interfacing.

Fig: 7 segments common anode display interfacing

Circuit Description

Both types of seven segment display internal connection are nearly the same. The difference is the polarity of the LEDs and common terminal. In a common cathode display, we need to connect common pins to ground and others pin to +5V. Alternatively, in a common anode display, we need to connect common pins +5V.

Arduino--------------------Seven Segment

Pin_1     ----------------   Pin_7 (Seg_a)

Pin_2     ----------------   Pin_6 (Seg_b)

Pin_3     ----------------   Pin_4 (Seg_c)

Pin_4     ----------------   Pin_2 (Seg_d)

Pin_5     ----------------   Pin_1 (Seg_e)

 Pin_6     -----------------  Pin_10 (Seg_f)

Pin_7     ----------------   Pin_9 (Seg_g)

Source Code

Overview

In this tutorial, we will learn how to interfacing 4*4 keypad with Arduino by a single analog pin. The use of a lot of pins can be reduced by following this procedure. It helps to use rest of pins for another purpose. For this tutorial, we will use a single analog pin to interfacing keypad with Arduino. 

You can watch the following video below:-

Components Required

Keypad Pinout

Fig 2.1: 4*4 Keypad Pinout

Circuit Schematic

The given below schematic is single wire keypad with Arduino:- 

Fig 3.1: One wire keypad with Arduino

Circuit Description

Fig: 4.1

Fig 4.2: One wire keypad with LCD using Arduino

Source Code