# LAB: GPIO Digital InOut 7-segment(eval board) ## LAB: GPIO Digital InOut 7-segment **Date:** 2025-09-02 **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: * eval board **Software** * PlatformIO, CMSIS, EC\_HAL library ## Exercise Fill in the table | **Port/Pin** | **Description** | **Register setting** | | --------------- | ---------------------------- | ----------------------------------------- | | Port B Pin 5 | Clear Pin5 mode | GPIOB->MODER &=\~(3<<(5\*2)) | | Port B Pin 5 | Set Pin5 mode = Output | GPIOB->MODER \|=\_\_\_\_\_\_\_\_\_\_\_\_ | | Port B Pin 6 | Clear Pin6 mode | GPIOB->MODER &=\~\_\_\_\_\_\_\_\_\_\_\_ | | Port B Pin 6 | Set Pin6 mode = Output | GPIOB->MODER \|=\_\_\_\_\_\_\_\_\_\_\_\_ | | Port B Pin Y | Clear PinY mode | GPIOB->MODER &=\~\_\_\_\_\_\_\_\_\_\_\_ | | Port B Pin Y | Set PinY mode = Output | GPIOB->MODER \|=\_\_\_\_\_\_\_\_\_\_\_\_ | | Port B Pin 5\~9 | Clear Pin5\~9 mode | GPIOB->MODER &=\~\_\_\_\_\_\_\_\_\_\_\_ | | | Set Pin5\~9 mode = Output | GPIOB->MODER \|=\_\_\_\_\_\_\_\_\_\_\_\_ | | Port X Pin Y | Clear Pin Y mode | GPIOX->MODER &=\~\_\_\_\_\_\_\_\_\_\_\_ | | | Set Pin Y mode = Output | GPIOX->MODER \|=\_\_\_\_\_\_\_\_\_\_\_\_ | | Port B Pin5 | Set Pin5 otype=push-pull | GPIOB->OTYPER =\_\_\_\_\_\_\_\_\_\_\_\_ | | Port B PinY | Set PinY otype=push-pull | GPIOB-> OTYPER =\_\_\_\_\_\_\_\_\_\_\_\_ | | Port B Pin5 | Set Pin5 ospeed=Fast | GPIOB->OSPEEDR =\_\_\_\_\_\_\_\_\_\_\_\_ | | Port B PinY | Set PinY ospeed=Fast | GPIOB-> OSPEEDR =\_\_\_\_\_\_\_\_\_\_\_\_ | | Port B Pin 5 | Set Pin5 PUPD=no pullup/down | GPIOB->OTYPER =\_\_\_\_\_\_\_\_\_\_\_\_ | | Port B Pin Y | Set PinY PUPD=no pullup/down | GPIOB-> OTYPER =\_\_\_\_\_\_\_\_\_\_\_\_ | *** ## Problem 0: Preparation ### Procedure Complete the Tutorial: 7-segment Display. {% embed url="" %} You must check the 7-segment display can show all the number from 0 to 9. * Give 'HIGH' signal to each 7-segment pin of 'a'\~'g' * Observe if that LED is turned ON or OFF * Check another 7-segment display leds * Example: Connect VCC to all 'a'\~'g' pins Complete the required functions that displays numbers on 7-segment FND. These functions must be moved to `ecGPIO2.h,ecGPIO2.c` Update your library header * **ecGPIO2.h, ecGPIO2.c** ```c // Initialize 7 DOUT pins for 7 segment leds void seven_seg_FND_init(void); // Select display: 0 to 3 // Display a number 0 - 9 only void seven_seg_FND_display(uint8_t num, uint8_t select); ``` ## Problem 1: Display a Number with Button Press ### Procedure 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”** * Update `platformio.ini` for VS.Code : [Read here for detail](https://ykkim.gitbook.io/ec/ec-course/tutorial/tutorial-platformio-in-vscode) \ 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 GPIO | Digital In for Button (B1) | Digital Out for 7-Segment | | -------------------------- | --------------------------------------------------------------------------------------------------------------------------- | | Digital In | Digital Out | | PA4 |

PB7,PB6,PB5,PB4,PB3,PB2,PB1,PB0
('a'\~'h', respectively)
PC3,PC4,PA11,PA10
('FND\_0'\~FND\_3, respectively)

| | PULL-UP | Push-Pull, No Pull-up-Pull-down, Medium Speed | ### Code [**Sample Code**](https://ykkim.gitbook.io/ec/stm32-m4-programming/example-code#seven-segment). ```c #include "stm32f4xx.h" #include "ecGPIO2.h" #include "ecRCC2.h" #define BUTTON_PIN PA_4 void setup(void){ // Intialize System Clock RCC_HSI_init(); GPIO_init(BUTTON_PIN, INPUT); // calls RCC_GPIOC_enable() // and Others // [YOUR CODE GOES HERE] seven_seg_FND_init(); }; int main(void) { setup(); uint8 numDisplay=8; uint8 selectFND=0; while (1) { // [YOUR CODE GOES HERE] seven_seg_FND_display(numDisplay,selectFND); // [YOUR CODE GOES HERE] // [YOUR CODE GOES HERE] } } ``` Your code goes here: [ADD Code LINK such as github](https://github.com/ykkimhgu/EC-student/) > Explain your source code with necessary comments. ``` // YOUR MAIN CODE ONLY // YOUR CODE ``` Your code goes here: [ADD Code LINK such as github](https://github.com/ykkimhgu/EC-student/) * [Example Code for MCU configuration](https://github.com/ykkimhgu/EC-student/blob/main/tutorial/tutorial-student/TU_GPIO_LED_7segment_student.c) * [Example code of 7-segment decoder control](https://os.mbed.com/users/ShingyoujiPai/code/7SegmentDisplay/file/463ff11d33fa/main.cpp/) > Explain your source code with the necessary comments. ``` // YOUR MAIN CODE ONLY // YOUR CODE ``` ### Connection Diagram Circuit diagram (if needed) > You need to include the circuit diagram ![image](https://user-images.githubusercontent.com/38373000/192134563-72f68b29-4127-42ac-b064-2eda95a9a52a.png) ### Results Experiment images and results > Show experiment images /results Add [demo video link](https://github.com/ykkimhgu/course-doc/blob/master/course/lab/link/README.md) ### Discussion 1. Analyze the result and explain any other necessary discussion. 2. Draw the truth table for the BCD 7-segment decoder with the 4-bit input. > Answer discussion questions ``` ** YOUR Truth-table goes here** ``` 3. What are the common cathode and common anode of 7-segment display? > Answer discussion questions 4. 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 *** ## Reference Complete list of all references used (github, blog, paper, etc) ``` ``` *** ## Troubleshooting (Option) You can write Troubleshooting section