ATmega16 Development Board Tutorial (2) - KEY Lighting

3. KEY lighting

The register definition of the KEY pin is the same as that of the LED, which is still 3 registers: DDRx, PORTx, and PINx (for details, please refer to the LED lighting section).

DDRx: 1-output, 0-input. When configured as input, PORTx=1, pull-up enabled, PORTx=0, high configuration, but pay attention to the third pin of SDIOR, which is used to disable pull-up, so pay attention when configuring pull-up, otherwise it will be high configuration.

Figure 2-2 SFIOR register diagram

Code Explanation:

ØDefine the corresponding bits of the 3 button pin registers. Again, use the underscore to get the bit position of the register.

ØButton initialization, while allowing pull-up

ØUse the key scanning program to detect whether the three keys are triggered. If yes, return the corresponding key value, otherwise return 0. Here, the key variable is used to determine whether the key is triggered, and the detection effect is better.

For other instructions, please refer to the original project. It also uses object-oriented structure function thinking for programming, improves the C language level, and keeps pace with the times.

Simulation video

/**

******************************************************************************

* @file main.c

* @author Alex——Xiaobai

* @version V1.0

* @date 2021.1.20

* @brief LED lighting

* @store Proteus simulation store

* @Link https://shop484534014.taobao.com/

* @Email 844545015@qq.com

******************************************************************************

* @attention All Rights Reserved  

**/

#include

void main(void)

{  

    LED.LED_Init(0xFF); //LED ALL OUTPUT

    KEY.KEY_Init(); //KEY 0/1/2 INPUT   

    while(1)

    {

        switch(KEY.KEY_Scan())

        {

            case 1:

                LED.LED_Reverse(0); //LED0 flip

                break;

            case 2:

                LED.LED_Reverse(1); //LED1 flip

                break;

            case 3:

                LED.LED_Reverse(2); //LED2 flip

                break;

            default:   

                break;            

        }

    }

}

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