/*
* ledfunc.c
*
* Created on: Jan 16, 2026
* Author: roman
*/
#include "main.h"
#include <string.h>
#include <stdio.h>
#include "ledfunc.h"
uint8_t flag = 0;
uint8_t blue_but_click_number = 0;
char pressedKey='\0';
char readChar='\0';
//UART_HandleTypeDef huart2;
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin) {
flag = !flag;
char main_str[50] = "Button clicked: ";
char num_str[45]; // Buffer to hold the string representation of the integer
// Convert the integer to a string
snprintf(num_str, sizeof(num_str), "%d times\r\n", ++blue_but_click_number);
// Concatenate the new string to the main string
// You must ensure main_str has enough allocated space for both parts
strncat(main_str, num_str, sizeof(main_str) - strlen(main_str) - 1);
HAL_UART_Transmit(&huart2, (uint8_t*)main_str, strlen(main_str), HAL_MAX_DELAY);
char msg[20];
sprintf(msg, "PRESSED: %c\r\n", pressedKey); // Formats string + char
HAL_UART_Transmit(&huart2, (uint8_t*)msg, strlen(msg), 100);
}
void ledblibk(int blinknum) {
for (int i = 0; i < blinknum; i++) {
HAL_GPIO_WritePin(LD2_GPIO_Port, LD2_Pin, GPIO_PIN_SET);
leddelay(500);
HAL_GPIO_WritePin(LD2_GPIO_Port, LD2_Pin, GPIO_PIN_RESET);
leddelay(500);
}
}
void leddelay(int ms) {
SysTick->LOAD = 16000 - 1;
SysTick->VAL = 0;
SysTick->CTRL = 0x5;
for (int i = 0; i < ms; i++) {
while (!(SysTick->CTRL & 0x10000)) {
}
}
SysTick->CTRL = 0;
}
void ledblink() {
if (1 == flag) {
HAL_GPIO_TogglePin( LD2_GPIO_Port, LD2_Pin);
HAL_Delay(50);
} else {
HAL_GPIO_WritePin(LD2_GPIO_Port, LD2_Pin, GPIO_PIN_RESET);
}
}
char Keypad_Read(void) {
char keypad_map[4][4] = {
{'1','2','3','A'},
{'4','5','6','B'},
{'7','8','9','C'},
{'*','0','#','D'}
};
for (int i = 0; i < 4; i++) {
// 1. Set current row to LOW (assuming Row pins are PC0-PC3)
HAL_GPIO_WritePin(GPIOC, (GPIO_PIN_0 << i), GPIO_PIN_RESET);
// 2. Check each column (assuming Column pins are PC4-PC7)
for (int j = 0; j < 4; j++) {
if (HAL_GPIO_ReadPin(GPIOC, (GPIO_PIN_4 << j)) == GPIO_PIN_RESET) {
while(HAL_GPIO_ReadPin(GPIOC, (GPIO_PIN_4 << j)) == GPIO_PIN_RESET); // Debounce/Wait for release
HAL_GPIO_WritePin(GPIOC, (GPIO_PIN_0 << i), GPIO_PIN_SET); // Reset row before returning
return keypad_map[i][j];
}
}
// 3. Set row back to HIGH
HAL_GPIO_WritePin(GPIOC, (GPIO_PIN_0 << i), GPIO_PIN_SET);
}
return 0; // No key pressed
}Hello all
I learn ( code below) !!!
Blue button is on EXTI - works. When press LED2 blinks, press again - LED stops blink ( work as expected)
Press on Blue button also sends message ( debugging purposes ) to Serial comm 9600 ( works as expected )
Now I added Keypad_Read() function to read pressed key ( this doesn't work ) Please advice me on getting
keypad only
connected 4x4 keypad as below
My code below
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* Copyright (c) 2026 STMicroelectronics.
* All rights reserved.
*
* This software is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
******************************************************************************
*/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include <string.h>
#include "ledfunc.h"
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
TIM_HandleTypeDef htim3;
UART_HandleTypeDef huart2;
/* USER CODE BEGIN PV */
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART2_UART_Init(void);
static void MX_TIM3_Init(void);
/* USER CODE BEGIN PFP */
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
/**
* @brief The application entry point.
* @retval int
*/
int main(void)
{
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_USART2_UART_Init();
MX_TIM3_Init();
/* USER CODE BEGIN 2 */
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1) {
ledblink();
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
}
/* USER CODE END 3 */
}
/**
* @brief System Clock Configuration
* @retval None
*/
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
/** Configure the main internal regulator output voltage
*/
__HAL_RCC_PWR_CLK_ENABLE();
__HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
/** Initializes the RCC Oscillators according to the specified parameters
* in the RCC_OscInitTypeDef structure.
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
RCC_OscInitStruct.PLL.PLLM = 16;
RCC_OscInitStruct.PLL.PLLN = 336;
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV4;
RCC_OscInitStruct.PLL.PLLQ = 4;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
/** Initializes the CPU, AHB and APB buses clocks
*/
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
|RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
{
Error_Handler();
}
}
/**
* @brief TIM3 Initialization Function
* @PAram None
* @retval None
*/
static void MX_TIM3_Init(void)
{
/* USER CODE BEGIN TIM3_Init 0 */
/* USER CODE END TIM3_Init 0 */
TIM_ClockConfigTypeDef sClockSourceConfig = {0};
TIM_MasterConfigTypeDef sMasterConfig = {0};
/* USER CODE BEGIN TIM3_Init 1 */
/* USER CODE END TIM3_Init 1 */
htim3.Instance = TIM3;
htim3.Init.Prescaler = 999;
htim3.Init.CounterMode = TIM_COUNTERMODE_UP;
htim3.Init.Period = 499;
htim3.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
htim3.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
if (HAL_TIM_Base_Init(&htim3) != HAL_OK)
{
Error_Handler();
}
sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
if (HAL_TIM_ConfigClockSource(&htim3, &sClockSourceConfig) != HAL_OK)
{
Error_Handler();
}
sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
if (HAL_TIMEx_MasterConfigSynchronization(&htim3, &sMasterConfig) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN TIM3_Init 2 */
HAL_TIM_Base_Start_IT(&htim3);
HAL_TIM_Base_Start(&htim3);
/* USER CODE END TIM3_Init 2 */
}
/**
* @brief USART2 Initialization Function
* @PAram None
* @retval None
*/
static void MX_USART2_UART_Init(void)
{
/* USER CODE BEGIN USART2_Init 0 */
/* USER CODE END USART2_Init 0 */
/* USER CODE BEGIN USART2_Init 1 */
/* USER CODE END USART2_Init 1 */
huart2.Instance = USART2;
huart2.Init.BaudRate = 9600;
huart2.Init.WordLength = UART_WORDLENGTH_8B;
huart2.Init.StopBits = UART_STOPBITS_1;
huart2.Init.Parity = UART_PARITY_NONE;
huart2.Init.Mode = UART_MODE_TX_RX;
huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE;
huart2.Init.OverSampling = UART_OVERSAMPLING_16;
if (HAL_UART_Init(&huart2) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN USART2_Init 2 */
/* USER CODE END USART2_Init 2 */
}
/**
* @brief GPIO Initialization Function
* @PAram None
* @retval None
*/
static void MX_GPIO_Init(void)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
/* USER CODE BEGIN MX_GPIO_Init_1 */
/* USER CODE END MX_GPIO_Init_1 */
/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOC_CLK_ENABLE();
__HAL_RCC_GPIOH_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
__HAL_RCC_GPIOB_CLK_ENABLE();
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(GPIOC, GPIO_PIN_0|GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3, GPIO_PIN_RESET);
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(LD2_GPIO_Port, LD2_Pin, GPIO_PIN_RESET);
/*Configure GPIO pin : B1_Pin */
GPIO_InitStruct.Pin = B1_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_IT_FALLING;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(B1_GPIO_Port, &GPIO_InitStruct);
/*Configure GPIO pins : PC0 PC1 PC2 PC3 */
GPIO_InitStruct.Pin = GPIO_PIN_0|GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);
/*Configure GPIO pin : LD2_Pin */
GPIO_InitStruct.Pin = LD2_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(LD2_GPIO_Port, &GPIO_InitStruct);
/*Configure GPIO pins : PC4 PC5 PC6 PC7 */
GPIO_InitStruct.Pin = GPIO_PIN_4|GPIO_PIN_5|GPIO_PIN_6|GPIO_PIN_7;
GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
GPIO_InitStruct.Pull = GPIO_PULLUP;
HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);
/* EXTI interrupt init*/
HAL_NVIC_SetPriority(EXTI15_10_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(EXTI15_10_IRQn);
/* USER CODE BEGIN MX_GPIO_Init_2 */
/* USER CODE END MX_GPIO_Init_2 */
}
/* USER CODE BEGIN 4 */
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim) {
if (htim == &htim3) {
//HAL_GPIO_TogglePin( LD2_GPIO_Port, LD2_Pin);
pressedKey=Keypad_Read() ;
}
}
/* USER CODE END 4 */
/**
* @brief This function is executed in case of error occurrence.
* @retval None
*/
void Error_Handler(void)
{
/* USER CODE BEGIN Error_Handler_Debug */
/* User can add his own implementation to report the HAL error return state */
__disable_irq();
while (1) {
}
/* USER CODE END Error_Handler_Debug */
}
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @PAram file: pointer to the source file name
* @PAram line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t *file, uint32_t line)
{
/* USER CODE BEGIN 6 */
/* User can add his own implementation to report the file name and line number,
ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
/* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */and
/*
* ledfunc.c
*
* Created on: Jan 16, 2026
* Author: roman
*/
#include "main.h"
#include <string.h>
#include <stdio.h>
#include "ledfunc.h"
uint8_t flag = 0;
uint8_t blue_but_click_number = 0;
char pressedKey='\0';
char readChar='\0';
//UART_HandleTypeDef huart2;
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin) {
flag = !flag;
char main_str[50] = "Button clicked: ";
char num_str[45]; // Buffer to hold the string representation of the integer
// Convert the integer to a string
snprintf(num_str, sizeof(num_str), "%d times\r\n", ++blue_but_click_number);
// Concatenate the new string to the main string
// You must ensure main_str has enough allocated space for both parts
strncat(main_str, num_str, sizeof(main_str) - strlen(main_str) - 1);
HAL_UART_Transmit(&huart2, (uint8_t*)main_str, strlen(main_str), HAL_MAX_DELAY);
char msg[20];
sprintf(msg, "PRESSED: %c\r\n", pressedKey); // Formats string + char
HAL_UART_Transmit(&huart2, (uint8_t*)msg, strlen(msg), 100);
}
void ledblibk(int blinknum) {
for (int i = 0; i < blinknum; i++) {
HAL_GPIO_WritePin(LD2_GPIO_Port, LD2_Pin, GPIO_PIN_SET);
leddelay(500);
HAL_GPIO_WritePin(LD2_GPIO_Port, LD2_Pin, GPIO_PIN_RESET);
leddelay(500);
}
}
void leddelay(int ms) {
SysTick->LOAD = 16000 - 1;
SysTick->VAL = 0;
SysTick->CTRL = 0x5;
for (int i = 0; i < ms; i++) {
while (!(SysTick->CTRL & 0x10000)) {
}
}
SysTick->CTRL = 0;
}
void ledblink() {
if (1 == flag) {
HAL_GPIO_TogglePin( LD2_GPIO_Port, LD2_Pin);
HAL_Delay(50);
} else {
HAL_GPIO_WritePin(LD2_GPIO_Port, LD2_Pin, GPIO_PIN_RESET);
}
}
char Keypad_Read(void) {
char keypad_map[4][4] = {
{'1','2','3','A'},
{'4','5','6','B'},
{'7','8','9','C'},
{'*','0','#','D'}
};
for (int i = 0; i < 4; i++) {
// 1. Set current row to LOW (assuming Row pins are PC0-PC3)
HAL_GPIO_WritePin(GPIOC, (GPIO_PIN_0 << i), GPIO_PIN_RESET);
// 2. Check each column (assuming Column pins are PC4-PC7)
for (int j = 0; j < 4; j++) {
if (HAL_GPIO_ReadPin(GPIOC, (GPIO_PIN_4 << j)) == GPIO_PIN_RESET) {
while(HAL_GPIO_ReadPin(GPIOC, (GPIO_PIN_4 << j)) == GPIO_PIN_RESET); // Debounce/Wait for release
HAL_GPIO_WritePin(GPIOC, (GPIO_PIN_0 << i), GPIO_PIN_SET); // Reset row before returning
return keypad_map[i][j];
}
}
// 3. Set row back to HIGH
HAL_GPIO_WritePin(GPIOC, (GPIO_PIN_0 << i), GPIO_PIN_SET);
}
return 0; // No key pressed
}
@Roman_E wrote:My apologies, but "reply" interface kinda complicated ( regarding previous thread)
Seriously?
There's a 'Reply' button on each post (the black one) - use that to make a reply specifically to one post;
There's also a box at the bottom of the page (with yellow button) - use that to make a general contribution to the topic:
But don't just abandon that thread.
People have made suggestions to you - so give them some feedback.
You can use @ to mention multiple people in one post.
For your keyboard scanning, forget about timers for now - just call it in a loop, and single-step in the debugger.
