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==KEYPAD_Init==
 
==KEYPAD_Init==
{| class="wikitable"  style="colspan:1; background-color:#4682B4;"
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{|{{Widget:LibCol}}
 
{{#Widget:LibTable}}
 
{{#Widget:LibTable}}
 
|-
 
|-
|Defination || '''void KEYPAD_Init()'''
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|Defination || void KEYPAD_Init()
 
|-
 
|-
 
| Input Arguments || none
 
| Input Arguments || none
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==KEYPAD_GetKey==
 
==KEYPAD_GetKey==
{| class="wikitable"  style="colspan:1; background-color:#4682B4;"
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{|{{Widget:LibCol}}
 
{{#Widget:LibTable}}
 
{{#Widget:LibTable}}
 
|-
 
|-
|Defination || '''unsigned char KEYPAD_GetKey()'''
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|Defination || unsigned char KEYPAD_GetKey()
 
|-
 
|-
 
| Input Arguments || none
 
| Input Arguments || none
 
|-
 
|-
| Return Value|| '''uint8_t'''--> ASCII value of the Key Pressed
+
| Return Value|| uint8_t: ASCII value of the Key Pressed
 
|-
 
|-
 
| 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.
 
 
|-
 
|-
 
| Usage ||
 
| Usage ||
 
|}
 
|}
  
 +
==Usage guide==
 +
<syntaxhighlight>
 +
#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*/
  
==KEYPAD_WaitForKeyRelease==
+
while(1)
{| class="wikitable"  style="colspan:1; background-color:#4682B4;"
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{
{{#Widget:LibTable}}
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key = KEYPAD_GetKey(); /*Get the Ascii value of the key Pressed */
|-
+
LCD_DisplayChar(key); /*Display the key pressed */
|Defination || '''void KEYPAD_WaitForKeyRelease()'''
+
}
|-
+
| Input Arguments || none
+
|-
+
| Return Value|| none
+
|-
+
| Description || This function waits till the previous key is released.
+
|-
+
| Usage ||
+
|}
+
  
 +
return 0;
 +
}
  
 
+
</syntaxhighlight>
 
+
==KEYPAD_WaitForKeyPress==
+
{| class="wikitable"  style="colspan:1; background-color:#4682B4;"
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{{#Widget:LibTable}}
+
|-
+
|Defination ||  '''void KEYPAD_WaitForKeyPress()'''
+
|-
+
| Input Arguments || none
+
|-
+
| Return Value|| none
+
|-
+
| Description ||  This function waits till a new key is pressed. The new Key pressed can be decoded by the function KEYPAD_GetKey.
+
|-
+
| Usage ||
+
|}
+

Latest revision as of 17:22, 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;
}