Lab 15: Matrix Keypad

Objective

Overview

Required Reading Material

• Lesson KB 01: Create a PSoC Project using PSoC Creator
• Datasheets:
  • DHT11 - Temperature and Humidity Sensor
  • DHT22 - Temperature and Humidity Sensor
  • RHT03 - Maxdetec Temperature and Humidity Sensor
• PSoC Creator Components
  • Pins
  • CharLCD

Required Components

The following components are required for this lab.

	4x4 Matrix Keypad	x 1
	Character LCD Module (4 x 20)	x 1

Circuit / Schematic

Procedure

Building the code and Programming

Firmware Template:

/* ========================================
 *
 * © 2024 AirSupplyLab. All rights reserved.
 * Unpublished, licensed software.
 *
 * This software contains confidential and proprietary
 * information owned by AirSupplyLab.com.
 *
 * ========================================
*/
#include "project.h"      // Include project-specific header files
#include <stdio.h>        // Standard library for input/output operations
#include <stdlib.h>       // Standard library for general-purpose functions
#include <stdint.h>       // Standard library for fixed-width integer types
#include <stdbool.h>      // Standard library for boolean data type

void ReadKeypad();        // Function prototype for keypad reading function

int main(void)
{
    char            key;          // Variable to store the key pressed
    char            str[50];      // Buffer to store strings for LCD output
    int32_t         value = 0;    // Variable to store numeric input
    unsigned int    i;            // Variable for loop counters or general use

    CyGlobalIntEnable; /* Enable global interrupts. */

    /* Place your initialization/startup code here (e.g. MyInst_Start()) */
    LCD_Start();
    LCD_ClearDisplay();
    LCD_Position(0,0);
    LCD_PrintString("PSoC5LP Keypad");
    CyDelay(1000);

    for(;;) {
        /* Place your application code here. */
        ReadKeypad();

        // Write your solution code here

        CyDelay(20);
    }
}
//------------------------------------------------------------------------------
char    KeyPad[][4] = {
                {'1', '2', '3', 'A'},
                {'4', '5', '6', 'B'},
                {'7', '8', '9', 'C'},
                {'*', '0', '#', 'D'} };
#define _BIT0   0x01
#define _BIT1   0x02
#define _BIT2   0x04
#define _BIT3   0x08
#define _BIT4   0x10
#define _BIT5   0x20
#define _BIT6   0x40
#define _BIT7   0x80

void ReadKeypad()
{
    int         i, j, row, col;
    char        ch;

    // Implete scan method to scan keypad

}
/* [] END OF FILE */

Exercises

Exp #02: 

In this lab, you will design an embedded system to meet the following requirements:

Functional Requirements:

1. Display Key Presses:
   • When the user presses any key on the keypad, the character will be displayed on the last row of the LCD screen.
   • The character should only be visible while the key is pressed. Once the key is released, the LCD will clear the character from the display.
2. Variable Manipulation:
   • The system will maintain an integer variable named value, initialized to 0.
   • When the user presses numeric keys (0 to 9), the system will:
     • Add the numeric value of that key to "value"
     • Update the LCD to display the new "value"
3. Special Key Functions:
   • Clear (* key): When the * key is pressed, reset "value" to 0., and display this updated value on the LCD.
   • Multiply by 10 (# key): When the # key is pressed, multiply the current value by 10 and display this updated value on the LCD.