桌面小屏幕实战课程：DesktopScreen 8 非易失性存储器NVS

飞书文档http://https://x509p6c8to.feishu.cn/docx/doxcnMFLIvzob6qCJPQQvRnlelf

非易失性存储器

/home/kemp/work/esp/esp-idf/examples/storage/nvs_rw_blob

源码下载方式参考：

源码下载方式

NVS 分区生成程序 - - ‒ ESP-IDF 编程指南 release-v4.1 文档

/* Non-Volatile Storage (NVS) Read and Write a Value - ExampleFor other examples please check:https://github.com/espressif/esp-idf/tree/master/examplesThis example code is in the Public Domain (or CC0 licensed, at your option.)Unless required by applicable law or agreed to in writing, thissoftware is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES ORCONDITIONS OF ANY KIND, either express or implied.
*/
#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_system.h"
#include "nvs_flash.h"
#include "nvs.h"
#include "esp_log.h"#include "ds_nvs.h"
#include "ds_system_data.h"static const char *TAG = "ds_nvs";NVS_WIFI_INFO_E wifi_config_flag = NVS_WIFI_INFO_NULL;void ds_nvs_save_wifi_info(){esp_err_t err;nvs_handle_t nvs_handle;err = nvs_open("wificonfig", NVS_READWRITE, &nvs_handle);if (err != ESP_OK) {ESP_LOGI(TAG,"Error (%s) opening NVS handle!\n", esp_err_to_name(err));return ;}wifi_config_flag = NVS_WIFI_INFO_SAVE;ESP_ERROR_CHECK(nvs_set_u8(nvs_handle, "wifi_flag", wifi_config_flag));ESP_ERROR_CHECK(nvs_set_str(nvs_handle, "ssid", get_system_data().setting_ssid));ESP_ERROR_CHECK(nvs_set_str(nvs_handle, "psw",  get_system_data().setting_psw));ESP_ERROR_CHECK(nvs_commit(nvs_handle));nvs_close(nvs_handle);
}NVS_WIFI_INFO_E ds_nvs_read_wifi_info(){esp_err_t err;nvs_handle_t nvs_handle;err = nvs_open("wificonfig", NVS_READWRITE, &nvs_handle);if (err != ESP_OK) {ESP_LOGI(TAG,"Error (%s) opening NVS handle!\n", esp_err_to_name(err));return NVS_WIFI_INFO_ERROR;}uint8_t wifi_config = 0;ESP_ERROR_CHECK(nvs_get_u8(nvs_handle, "wifi_flag", &wifi_config));wifi_config_flag = wifi_config;if(wifi_config_flag == NVS_WIFI_INFO_SAVE){ESP_LOGI(TAG,"has wifi config info");char ssid[32];char psw[64];size_t ssid_len = sizeof(ssid);size_t psw_len = sizeof(psw);ESP_ERROR_CHECK(nvs_get_str(nvs_handle, "ssid", ssid, &ssid_len));ESP_ERROR_CHECK(nvs_get_str(nvs_handle, "psw", psw, &psw_len));set_system_data_wifi_info(ssid,ssid_len,psw,psw_len);print_system_data_wifi_info();}else{ESP_LOGI(TAG,"wifi config info null");}nvs_close(nvs_handle);return wifi_config_flag;
}void ds_nvs_init(){// Initialize NVSesp_err_t err = nvs_flash_init();if (err == ESP_ERR_NVS_NO_FREE_PAGES || err == ESP_ERR_NVS_NEW_VERSION_FOUND) {// NVS partition was truncated and needs to be erased// Retry nvs_flash_initESP_ERROR_CHECK(nvs_flash_erase());err = nvs_flash_init();}ESP_ERROR_CHECK( err );
}