OVMS3-idf/examples/07_nvs_rw_value/main/nvs_rw_value.c
2016-11-22 21:54:49 +08:00

81 lines
2.4 KiB
C

/* Non-Volatile Storage (NVS) Read and Write a Value - Example
For other examples please check:
https://github.com/espressif/esp-idf/tree/master/examples
This example code is in the Public Domain (or CC0 licensed, at your option.)
Unless required by applicable law or agreed to in writing, this
software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
CONDITIONS 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"
void app_main()
{
nvs_flash_init();
nvs_handle my_handle;
esp_err_t err;
printf("\n");
// Open
printf("Opening Non-Volatile Storage (NVS) ... ");
err = nvs_open("storage", NVS_READWRITE, &my_handle);
if (err != ESP_OK) {
printf("Error (%d) opening NVS!\n", err);
} else {
printf("Done\n");
// Read
printf("Reading restart counter from NVS ... ");
int32_t restart_counter = 0; // value will default to 0, if not set yet in NVS
err = nvs_get_i32(my_handle, "restart_conter", &restart_counter);
switch (err) {
case ESP_OK:
printf("Done\n");
printf("Restart counter = %d\n", restart_counter);
break;
case ESP_ERR_NVS_NOT_FOUND:
printf("The value is not initialized yet!\n");
break;
default :
printf("Error (%d) reading!\n", err);
}
// Write
printf("Updating restart counter in NVS ... ");
restart_counter++;
err = nvs_set_i32(my_handle, "restart_conter", restart_counter);
printf((err != ESP_OK) ? "Failed!\n" : "Done\n");
// Commit written value.
// After setting any values, nvs_commit() must be called to ensure changes are written
// to flash storage. Implementations may write to storage at other times,
// but this is not guaranteed.
printf("Committing updates in NVS ... ");
err = nvs_commit(my_handle);
printf((err != ESP_OK) ? "Failed!\n" : "Done\n");
// Close
nvs_close(my_handle);
}
printf("\n");
// Restart module
for (int i = 10; i >= 0; i--) {
printf("Restarting in %d seconds...\n", i);
vTaskDelay(1000 / portTICK_RATE_MS);
}
printf("Restarting now.\n");
fflush(stdout);
esp_restart();
}