/**
 ******************************************************************************
 * @file           : main.c
 * @author         : Auto-generated by STM32CubeIDE
 * @brief          : Main program body
 ******************************************************************************
 * @attention
 *
 * Copyright (c) 2024 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.
 *
 ******************************************************************************
 */

#include <stdint.h>
#include "STM32F103IO.h"
#include "Keypad.h"
#include "LCD1602.h"


#if !defined(__SOFT_FP__) && defined(__ARM_FP)
  #warning "FPU is not initialized, but the project is compiling for an FPU. Please initialize the FPU before use."
#endif





int main(void)
{
	volatile char key;

	keypad_Init();
	LCD_Init();

	LCD_Clear();                   // Clear the LCD
	LCD_Cursor(0, 5);              // Set the cursor at 1st row, 6th column
	LCD_String("Keypad");
	LCD_Cursor(1, 0);              // Set the cursor at 2nd row, 1st column

	while(1){
		key = keypad();
		if(key){
			LCD_Char(key);              // Print the character into LCD
		  delay_ms(700);              // Keypad debouncing delaly
		}
	}
}


stm32-spi-lcd.ino

diagram.json

# Wokwi Library List
# See https://docs.wokwi.com/guides/libraries

Adafruit GFX Library
Adafruit ILI9341


libraries.txt

#ifndef STM32F103IO_h
#define STM32F103IO_h




#define       GPIOA_IN             *porta_input_reg
#define       GPIOA_OUT            *porta_output_reg
#define       GPIOB_IN             *portb_input_reg
#define       GPIOB_OUT            *portb_output_reg
#define       GPIOC_IN             *portc_input_reg
#define       GPIOC_OUT            *portc_output_reg

#define       RCC_base_add         0x40021000
#define       APB2_offset          0x18
#define       PORTA_base_add       0x40010800
#define       PORTB_base_add       0x40010C00
#define       PORTC_base_add       0x40011000
#define       GPIO_CRL_offset      0x00
#define       GPIO_CRH_offset      0x04
#define       GPIO_ODR_offset      0x0C
#define       GPIO_IDR_offset      0x08

#define       input_mode           8
#define       output_mode          2
#define       clear                15
#define       GPIOA               'A'
#define       GPIOB               'B'
#define       GPIOC               'C'
#define       IN                   0
#define       OUT                  1





volatile uint32_t *clock_reg    =   (uint32_t*) (RCC_base_add + APB2_offset);

volatile uint32_t *porta_mode_reg_low     =    (uint32_t*) (PORTA_base_add + GPIO_CRL_offset);
volatile uint32_t *porta_mode_reg_high    =    (uint32_t*) (PORTA_base_add + GPIO_CRH_offset);
volatile uint32_t *porta_input_reg        =    (uint32_t*) (PORTA_base_add + GPIO_IDR_offset);
volatile uint32_t *porta_output_reg       =    (uint32_t*) (PORTA_base_add + GPIO_ODR_offset);

volatile uint32_t *portb_mode_reg_low     =    (uint32_t*) (PORTB_base_add + GPIO_CRL_offset);
volatile uint32_t *portb_mode_reg_high    =    (uint32_t*) (PORTB_base_add + GPIO_CRH_offset);
volatile uint32_t *portb_input_reg        =    (uint32_t*) (PORTB_base_add + GPIO_IDR_offset);
volatile uint32_t *portb_output_reg       =    (uint32_t*) (PORTB_base_add + GPIO_ODR_offset);

volatile uint32_t *portc_mode_reg_low     =    (uint32_t*) (PORTC_base_add + GPIO_CRL_offset);
volatile uint32_t *portc_mode_reg_high    =    (uint32_t*) (PORTC_base_add + GPIO_CRH_offset);
volatile uint32_t *portc_input_reg        =    (uint32_t*) (PORTC_base_add + GPIO_IDR_offset);
volatile uint32_t *portc_output_reg       =    (uint32_t*) (PORTC_base_add + GPIO_ODR_offset);





void GPIO_mode(volatile char port_name, volatile uint32_t pin_number, volatile uint32_t mode){


/*---------------------------------------------------------------------------------------------------------*/
/*                                           PORTA pin configuration                                       */
/*---------------------------------------------------------------------------------------------------------*/


  if(port_name == 'A'){
    /* Enable PORTA */
    *clock_reg |=  (1 << 2); 

/* If the pin is belongs to LOWER BYTE */
    if((pin_number >= 0) && (pin_number <= 7)){
    /* Clear the respective pin mode & config bits */
      *porta_mode_reg_low    &=     ~(clear << (4*pin_number));

           if(mode == 1) *porta_mode_reg_low |= (output_mode << (4*pin_number));  /* Mode == 1 means OUTPUT */
      else if(mode == 0) *porta_mode_reg_low |= (input_mode << (4*pin_number));    /* Mode == 0 means INPUT */
    }


/* If the pin is belongs to HIGHER BYTE */
    else if((pin_number >= 8) && (pin_number <= 15)){
      /* for clear the respective pin mode & config bits */
      *porta_mode_reg_high &= ~(clear << (4*(pin_number - 8)));

           if(mode == 1) *porta_mode_reg_high |= (output_mode << (4*(pin_number - 8)));   /* Mode == 1 means OUTPUT */
      else if(mode == 0) *porta_mode_reg_high |= (input_mode << (4*(pin_number - 8)));    /* Mode == 0 means INPUT */
    }
  }


/*---------------------------------------------------------------------------------------------------------*/
/*                                           PORTB pin configuration                                       */
/*---------------------------------------------------------------------------------------------------------*/


    else if(port_name == 'B'){
    /* Enable PORTB */
    *clock_reg |=  (1 << 3); 

/* If the pin is belongs to LOWER BYTE */
    if((pin_number >= 0) && (pin_number <= 7)){
    /* Clear the respective pin mode & config bits */
      *portb_mode_reg_low    &=     ~(clear << (4*pin_number));

           if(mode == 1) *portb_mode_reg_low |= (output_mode << (4*pin_number));   /* Mode == 1 means OUTPUT */
      else if(mode == 0) *portb_mode_reg_low |= (input_mode << (4*pin_number));    /* Mode == 0 means INPUT */
    }


/* If the pin is belongs to HIGHER BYTE */
    else if((pin_number >= 8) && (pin_number <= 15)){
      /* for clear the respective pin mode & config bits */
      *portb_mode_reg_high &= ~(clear << (4*(pin_number - 8)));

           if(mode == 1) *portb_mode_reg_high |= (output_mode << (4*(pin_number - 8)));   /* Mode == 1 means OUTPUT */
      else if(mode == 0) *portb_mode_reg_high |= (input_mode << (4*(pin_number - 8)));    /* Mode == 0 means INPUT */
    }
  }


/*---------------------------------------------------------------------------------------------------------*/
/*                                           PORTC pin configuration                                       */
/*---------------------------------------------------------------------------------------------------------*/


    else if(port_name == 'C'){
    /* Enable PORTC */
    *clock_reg |=  (1 << 4); 

/* If the pin is belongs to LOWER BYTE */
    if((pin_number >= 0) && (pin_number <= 7)){
    /* Clear the respective pin mode & config bits */
      *portc_mode_reg_low    &=     ~(clear << (4*pin_number));

           if(mode == 1) *portc_mode_reg_low |= (output_mode << (4*pin_number));   /* Mode == 1 means OUTPUT */
      else if(mode == 0) *portc_mode_reg_low |= (input_mode << (4*pin_number));    /* Mode == 0 means INPUT */
    }


/* If the pin is belongs to HIGHER BYTE */
    else if((pin_number >= 8) && (pin_number <= 15)){
      /* for clear the respective pin mode & config bits */
      *portc_mode_reg_high &= ~(clear << (4*(pin_number - 8)));

           if(mode == 1) *portc_mode_reg_high |= (output_mode << (4*(pin_number - 8)));   /* Mode == 1 means OUTPUT */
      else if(mode == 0) *portc_mode_reg_high |= (input_mode << (4*(pin_number - 8)));    /* Mode == 0 means INPUT */
    }
  }
}



void GPIO_write(volatile char port_name, volatile uint32_t pin_number, volatile uint32_t pin_state){
  if(port_name == 'A'){
         if(pin_state == 1) *porta_output_reg |=  (1 << pin_number);
    else if(pin_state == 0) *porta_output_reg &= ~(1 << pin_number);
  }

  else if(port_name == 'B'){
         if(pin_state == 1) *portb_output_reg |=  (1 << pin_number);
    else if(pin_state == 0) *portb_output_reg &= ~(1 << pin_number);
  }

  if(port_name == 'C'){
         if(pin_state == 1) *portc_output_reg |=  (1 << pin_number);
    else if(pin_state == 0) *portc_output_reg &= ~(1 << pin_number);
  }
}



volatile uint32_t GPIO_read(volatile char port_name, volatile uint32_t pin_number){
       if(port_name == 'A') return ((*porta_input_reg >> pin_number) & 1);
  else if(port_name == 'B') return ((*portb_input_reg >> pin_number) & 1);
  else if(port_name == 'C') return ((*portc_input_reg >> pin_number) & 1);
}



/* Mili second delay */
void delay_ms(volatile uint16_t time){
	volatile uint16_t x, y;
	for(x=0; x<time; x++)
	for(y=0; y<235; y++);
}


/* Micro second delay */
void delay_us(volatile uint16_t time){
	for(volatile uint16_t x=0; x<time; x++);
}





#endif


STM32F103IO.h

#ifndef Keypad_h
#define Kepayd_h




#include "STM32F103IO.h"



void keypad_Init()
{
  GPIO_mode(GPIOA, 4, OUT);
	GPIO_mode(GPIOA, 5, OUT);
	GPIO_mode(GPIOA, 6, OUT);
	GPIO_mode(GPIOA, 7, OUT);

	GPIO_mode(GPIOA, 0, IN);
	GPIO_mode(GPIOA, 1, IN);
	GPIO_mode(GPIOA, 2, IN);
	GPIO_mode(GPIOA, 3, IN);
}


volatile char keypad()
{
	volatile char row, col, key;

	for(row=0; row<4; row++){
		GPIOA_OUT &= ~(0x0F << 4);        // clear the keypad connected output pin
		GPIOA_OUT |= (1 << (row + 4));
		if(GPIOA_IN  & 0x0F){ col = (GPIOA_IN  & 0x0F); break;}
	}


	if(row == 0){
         if(col == 1) key = '1';
    else if(col == 2) key = '2';
    else if(col == 4) key = '3';
    else if(col == 8) key = 'A';
  }
  else if(row == 1){
         if(col == 1) key = '4';
    else if(col == 2) key = '5';
    else if(col == 4) key = '6';
    else if(col == 8) key = 'B';
  }
  else if(row==2){
         if(col == 1) key = '7';
    else if(col == 2) key = '8';
    else if(col == 4) key = '9';
    else if(col == 8) key = 'C';
  }
  else if(row == 3){
         if(col == 1) key = '*';
    else if(col == 2) key = '0';
    else if(col == 4) key = '#';
    else if(col == 8) key = 'D';
  }
  else key = 0;
  return key;
}





#endif



Keypad.h

#ifndef LCD1602_h_
#define LCD1602_h_




#include "STM32F103IO.h"



#define           en            0x200
#define           rs            0x100



void LCD_Command (volatile uint8_t cmnd)
{
	GPIOB_OUT &= ~(0x3F << 4);       // Clear the LCD connected pins
	GPIOB_OUT |= (cmnd & 0xF0);      // Send upper nibble 
	GPIOB_OUT |= en;                 // en = 1, rs = 0
	delay_us(50);
	GPIOB_OUT &= ~(en);              // en = 0, rs = 0
	delay_us(50);

	GPIOB_OUT &= ~(0x3F << 4);            // Clear the LCD connected pins
	GPIOB_OUT |= ((cmnd & 0x0F) << 4);    // Send lower nibble 
	GPIOB_OUT |= en;                      // en = 1, rs = 0
	delay_us(50);
	GPIOB_OUT &= ~(en);                   // en = 0, rs = 0
	delay_us(50);
}



void LCD_Char(volatile uint8_t data)	
{
	GPIOB_OUT &= ~(0x3F << 4);       // Clear the LCD connected pins
	GPIOB_OUT |= (data & 0xF0);      // Send upper nibble 
	GPIOB_OUT |= (en + rs);          // en = 1, rs = 1
	delay_us(50); 
	GPIOB_OUT &= ~(en);              // en = 0, rs = 1
	delay_us(50);

	GPIOB_OUT &= ~(0x3F << 4);            // Clear the LCD connected pins
	GPIOB_OUT |= ((data & 0x0F) << 4);    // Send lower nibble 
	GPIOB_OUT |= (en + rs);               // en = 1, rs = 1
	delay_us(50);
	GPIOB_OUT &= ~(en);                   // en = 0, rs = 1
	delay_us(50);
}



void LCD_String(volatile const char *str)	// Send string to LCD function 
{
	int i;
	for(i=0;str[i]!=0;i++)  // Send each volatile uint8_t of string till the NULL 
	{
		LCD_Char (str[i]);  // Call LCD data write 
	}
}



void LCD_Init(){
	GPIO_mode(GPIOB, 4, OUT);
	GPIO_mode(GPIOB, 5, OUT);
	GPIO_mode(GPIOB, 6, OUT);
	GPIO_mode(GPIOB, 7, OUT);
	GPIO_mode(GPIOB, 8, OUT);
	GPIO_mode(GPIOB, 9, OUT);

	delay_us(50);	         	// LCD Power ON Initialization time >15ms 
	LCD_Command (0x02);    	// 4bit mode
	LCD_Command (0x28);	    //  4bit mode 
	LCD_Command (0x0C);	    //Display ON Cursor OFF 
	LCD_Command (0x06);   	// Auto Increment cursor 
	LCD_Command (0x01);	    // Clear display
	LCD_Command (0x80);	    // Cursor at home position
}



void LCD_Cursor(volatile uint8_t row, volatile uint8_t column){
  if(row==0) LCD_Command(0x80 + column);
  else if(row==1) LCD_Command(0xc0 + column);
}



void LCD_Clear(){
  LCD_Command(0x01);
}





#endif

