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| Description ||  This function waits till a key is pressed and returns its ASCII Value.
 
| Description ||  This function waits till a key is pressed and returns its ASCII Value.
It follows the following sequences to decode the key pressed:
 
*Wait till the previous key is released..
 
*Wait for the new key press.
 
*Scan all the rows one at a time for the pressed key.
 
*Decodes the key pressed depending on ROW-COL combination and returns its
 
  ASCII value.
 
 
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|-
 
| Usage ||
 
| Usage ||
 
|}
 
|}
 
 
 
 
  
 
==Usage guide==
 
==Usage guide==

Revision as of 12:05, 28 December 2014


KEYPAD

KEYPAD_Init

{{#Widget:LibTable}}
Defination void KEYPAD_Init()
Input Arguments none
Return Value none
Description This function configures the rows and columns for keypad scan.
  • ROW lines are configured as Output.
  • Column Lines are configured as Input.
Usage



KEYPAD_GetKey

{{#Widget:LibTable}}
Defination unsigned char KEYPAD_GetKey()
Input Arguments none
Return Value uint8_t--> ASCII value of the Key Pressed
Description This function waits till a key is pressed and returns its ASCII Value.
Usage

Usage guide

#include"keypad.h"
#include"lcd.h"
#include "delay.h"   
 
 
/* Program to demonstrate the hex-Keypad interface*/
int  main()
{
  uint8_t key;
  LCD_Init(8,2,16);            /*Initialize the 2x16 LCD in 8-bit mode */
  KEYPAD_Init();               /*Configure the ROWs and COLUMNs for keypad scanning*/
 
	while(1)
	{
		key = KEYPAD_GetKey(); /*Get the Ascii value of the key Pressed */
		LCD_DisplayChar(key);  /*Display the key pressed */
	}
 
	return 0;
}