LAB: GPIO Digital InOut 7-segment

LAB: GPIO Digital InOut 7-segment

Date: 2024-09-1

Author/Partner:

Github: repository link

Demo Video: Youtube link

PDF version:

Introduction

In this lab, you are required to create a simple program to control a 7-segment display to show a decimal number (0~9) that increases by pressing a push-button.

You must submit

• LAB Report (*.pdf)

• Zip source files(LAB***.c, ecRCC2.h, ecGPIO2.h etc...).

  • Only the source files. Do not submit project files

Requirement

Hardware

• MCU

  • NUCLEO-F411RE

• Actuator/Sensor/Others:

  • 7-segment display(5101ASR)

  • Array resistor (330 ohm)

  • decoder chip(74LS47)

  • breadboard

Software

• Keil uVision, CMSIS, EC_HAL library

Exercise

Fill in the table

Port/Pin	Description	Register setting
Port A Pin 5	Clear Pin5 mode	GPIOA->MODER &=~(3<<(5*2))
Port A Pin 5	Set Pin5 mode = Output	GPIOA->MODER |=____________
Port A Pin 6	Clear Pin6 mode	GPIOA->MODER &=~___________
Port A Pin 6	Set Pin6 mode = Output	GPIOA->MODER |=____________
Port A Pin Y	Clear PinY mode	GPIOA->MODER &=~___________
Port A Pin Y	Set PinY mode = Output	GPIOA->MODER |=____________
Port A Pin 5~9	Clear Pin5~9 mode	GPIOA->MODER &=~___________
	Set Pin5~9 mode = Output	GPIOA->MODER |=____________
Port X Pin Y	Clear Pin Y mode	GPIOX->MODER &=~___________
	Set Pin Y mode = Output	GPIOX->MODER |=____________
Port A Pin5	Set Pin5 otype=push-pull	GPIOA->OTYPER =____________
Port A PinY	Set PinY otype=push-pull	GPIOA-> OTYPER =____________
Port A Pin5	Set Pin5 ospeed=Fast	GPIOA->OSPEEDR =____________
Port A PinY	Set PinY ospeed=Fast	GPIOA-> OSPEEDR =____________
Port A Pin 5	Set Pin5 PUPD=no pullup/down	GPIOA->OTYPER =____________
Port A Pin Y	Set PinY PUPD=no pullup/down	GPIOA-> OTYPER =____________

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Problem 0: Connection of 7-Segment Display and Decoder

Procedure

Review 7-segment Decoder and Display from Digital Logic lecture.

• Read here: 7-segment tutorial
• Read here: How to connect 7-segment decoder to MCU

1. 7-segment display connection

First, connect the common anode 7-segment display with the given array resistors.

Then, apply VCC and GND to the 7-segment display.

Check that all LEDs of 7-segment work properly

• Give 'H' signal to each 7-segment pin of 'a'~'g' . Observe if that LED is turned ON or OFF

• Example: Connect VCC to all 'a'~'g' pins

2. BCD 7-segment decoder connection

The popular BCD 7-segment decoder chip is 74LS47. With the BCD chip, you need only 4 DOUT pins of MCU to display from 0 to 9.

Connect the decoder chip (74LS47) on the bread board.

Then, Check that the decoder chip works properly

• Supply a combination of VCC/GND to the pins of 'A'~'D' of the decoder.

• Check if the 7-segment LED display shows the correct number

Connection Diagram

Circuit diagram

You need to include the circuit diagram in the report

image

Discussion

1. Draw the truth table for the BCD 7-segment decoder with the 4-bit input.

Answer discussion questions

** YOUR Truth-table  goes here**

1. What are the common cathode and common anode of 7-segment display?

Answer discussion questions

1. Does the LED of a 7-segment display (common anode) pin turn ON when 'HIGH' is given to the LED pin from the MCU?

Answer discussion questions

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Problem 1: Display a Number with Button Press

Procedure

1. Create a new project under the directory \repos\EC\LAB\LAB_GPIO_7segment

• The project name is “LAB_GPIO_7segment”.

• Create a new source file named as “LAB_GPIO_7segment.c”

• Refer to the sample code

  You MUST write your name on the source file inside the comment section.

1. Include your updated library in \repos\EC\lib\ to your project.

• ecGPIO.h, ecGPIO.c

• ecRCC.h, ecRCC.c

1. Declare and Define the following functions in your library

void sevensegment_display_init(PinNames_t pinNameA, PinNames_t pinNameB, PinNames_t pinNameC, PinNames_t pinNameD); 
void sevensegment_display(uint8_t  num);

• num: 0 to 9 only (unsigned)

1. Configure and connect the MCU to the circuit

2. First, check that every number, 0 to 9, can be displayed properly

3. Then, create a code that increase the displayed number from 0 to 9 with each button press.

   • After the number '9', it should start from '0' again.

Configuration

Configure the MCU

Digital In for Button (B1)	Digital Out for 7-Segment
Digital In	Digital Out
PC13	PA7, PB6, PC7, PA9
PULL-UP	Push-Pull, No Pull-up-Pull-down, Medium Speed

Code

Sample Code.

#include "stm32f4xx.h"
#include "ecGPIO2.h"
#include "ecRCC2.h"

#define LED_PIN PA_5
#define BUTTON_PIN PC_13

void setup(void);
	
int main(void) { 
	// Initialiization --------------------------------------------------------
	setup();
	unsigned int cnt = 0;
	
	// Inifinite Loop ----------------------------------------------------------
	while(1){
		sevensegment_display(cnt % 10);
		if(GPIO_read(BUTTON_PIN) == 0) cnt++; 
        if (cnt > 9) cnt = 0;
		for(int i = 0; i < 500000;i++){}  // delay_ms(500);
	}
}


// Initialiization 
void setup(void)
{
	RCC_HSI_init();	
	GPIO_init(BUTTON_PIN, INPUT);  // calls RCC_GPIOC_enable()
	sevensegment_display_init(PA_7, PB_6, PC_7, PA_9);  // Decoder input A,B,C,D
}

Your code goes here: ADD Code LINK such as github

Explain your source code with necessary comments.

// YOUR MAIN CODE ONLY
// YOUR CODE

Results

Experiment images and results

Show experiment images /results

Add demo video link

Discussion

Analyze the result and explain any other necessary discussion.

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Problem 2: Program BCD-7-segment decoder

Instead of using the decoder chip, we are going to make the 7-segment decoder with the MCU programming.

Do not use the 7-segment decoder for this problem

Procedure

1. Use the same project and source file.

2. Include your updated library in \repos\EC\lib\ to your project.

• ecGPIO.h, ecGPIO.c

• ecRCC.h, ecRCC.c

1. Declare and Define the following functions in your library

void sevensegment_decoder_init(void); 
void sevensegment_decoder(uint8_t  num);

• num: 0 to 9 only (unsigned)

1. Configure and connect the MCU to the circuit

2. First, check that every number, 0 to 9, can be displayed properly

3. Then, create a code that increases the displayed number from 0 to 9 with each button press.

   • After the number '9', it should start from '0' again.

Configuration

Configure the MCU

Digital In for Button (B1)	Digital Out for 7-Segment
Digital In	Digital Out
PC13	PA5, PA6, PA7, PB6, PC7, PA9, PA8, PB10 ('a'~'h', respectively)
PULL-UP	Push-Pull, No Pull-up-Pull-down, Medium Speed

Code

Your code goes here: ADD Code LINK such as github

• Example Code for MCU configuration
• Example code of 7-segment decoder control

Explain your source code with the necessary comments.

// YOUR MAIN CODE ONLY
// YOUR CODE

Connection Diagram

Circuit diagram

You need to include the circuit diagram

image

Results

Experiment images and results

Show experiment images /results

Add demo video link

Discussion

Analyze the result and explain any other necessary discussion.

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Reference

Complete list of all references used (github, blog, paper, etc)

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Troubleshooting

(Option) You can write Troubleshooting section