M5Stack/examples/Advanced/Storage/Counter/Counter.ino

/*
*******************************************************************************
* Copyright (c) 2023 by M5Stack
*                  Equipped with M5Core sample source code
*                          配套  M5Core 示例源代码
* Visit for more information: https://docs.m5stack.com/en/core/gray
* 获取更多资料请访问: https://docs.m5stack.com/zh_CN/core/gray
*
* Describe: counter.  计数器
* Date: 2021/8/3
*******************************************************************************
*/

#include <M5Stack.h>
#include <Preferences.h>

Preferences preferences;

void setup() {
    M5.begin();        // Init M5Core.  初始化 M5Core
    M5.Power.begin();  // Init power  初始化电源模块
    M5.Lcd.setTextSize(2);
    preferences.begin(
        "my-app",
        false);  // We will open storage in RW-mode (second parameter has to be
                 // false).
                 // 在perferences中创建叫my-app的空间,并以rw模式打开存储(第二个参数必须为false)

    // preferences.clear();  // Remove all preferences under the opened
    // namespace.清除preferences中所有的空间

    // preferences.remove("counter");  // Or remove the counter key only.
    // 只清除counter中的值

    unsigned int counter = preferences.getUInt(
        "counter",
        0);  // Get the counter value in current sapce, if the key does not
             // exist, return a default value of 0.
             // 在当前空间中读取counter的值(若不存在为0),并赋值给counter
    counter++;  // Increase counter by 1.  使计数器的值加一
    M5.Lcd.printf(
        "Current counter value: %u\n",
        counter);  // Print the counter to Serial Monitor.  串口输出计数器的值
    preferences.putUInt(
        "counter",
        counter);  // Store the counter to the Preferences.  存储计数器的值
    preferences.end();  // Close the Preferences.  关闭Preferences
    M5.Lcd.println("Restarting in 10 seconds..");
    delay(10000);   // delay 10.  延迟10s
    ESP.restart();  // Restart.  重启
}
void loop() {
}