【Arduino】168种传感器模块系列实验(资料 +代码 +图形 +仿真)
实验一百四十二:LCD1602 字符液晶屏 输入输出扩展板 LCD Keypad Shield
实验之二:ADC密钥测试
LiquidCrystal库:IDE—工具—管理库—搜索LiquidCrystal—安装
*/
#include <LiquidCrystal.h>
LiquidCrystal lcd(8, 9, 4, 5, 6, 7);
char msgs = {"Right Key OK ",
"Up Key OK ",
"Down Key OK",
"Left Key OK",
"Select Key OK"
};
int adc_key_val = {50, 200, 400, 600, 800 };
int NUM_KEYS = 5;
int adc_key_in;
int key = -1;
int oldkey = -1;
void setup()
{
lcd.clear();
lcd.begin(16, 2);
lcd.setCursor(0, 0);
lcd.print("ADC key testing");
}
void loop()
{
adc_key_in = analogRead(0); // 从A0传感器端读取值
key = get_key(adc_key_in);// 转换为按键
if (key != oldkey) // 如果检测到按键
{
delay(50);// 等待解除缓冲时间
adc_key_in = analogRead(0); // 从A0传感器端读取值
key = get_key(adc_key_in); // 转换为按键
if (key != oldkey)
{
lcd.setCursor(0, 1);
oldkey = key;
if (key >= 0) {
lcd.print(msgs);
}
}
}
delay(100);
}
// 将ADC值转换为密钥号
int get_key(unsigned int input)
{
int k;
for (k = 0; k < NUM_KEYS; k++)
{
if (input < adc_key_val)
{
return k;
}
}
if (k >= NUM_KEYS)k = -1;// 未按下有效键
return k;
}
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