Krzysztof
025bb47302
Demonstrates how to read and write a value using NVS. The value tracks number of ESP32 module restarts. Example also shows how to use basic diagnostics if read / write operation was successful.
63 lines
1.8 KiB
C
63 lines
1.8 KiB
C
/* Non-Volatile Storage (NVS) Read and Write Example
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This example code is in the Public Domain (or CC0 licensed, at your option.)
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Unless required by applicable law or agreed to in writing, this
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software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
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CONDITIONS OF ANY KIND, either express or implied.
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*/
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#include <stdio.h>
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#include "freertos/FreeRTOS.h"
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#include "freertos/task.h"
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#include "esp_system.h"
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#include "nvs_flash.h"
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#include "nvs.h"
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void app_main()
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{
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nvs_flash_init();
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system_init();
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nvs_handle handle_to_settings;
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esp_err_t err;
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int32_t restart_counter = 0;
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// Open the NVS
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printf("Opening Non-Volatile Storage (NVS) ... ");
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err = nvs_open("settings", NVS_READWRITE, &handle_to_settings);
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printf((err != ESP_OK) ? "Failed!\n" : "OK\n");
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// Read from the NVS
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printf("Reading restart counter from NVS ... ");
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err = nvs_get_i32(handle_to_settings, "restart_conter", &restart_counter);
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switch (err) {
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case ESP_OK:
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printf("OK\n");
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printf("Restart counter = %d\n", restart_counter);
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break;
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case ESP_ERR_NVS_NOT_FOUND:
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printf("The counter is not initialized yet!\n");
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break;
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default :
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printf("Error (%d) reading!\n", err);
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}
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// Write to the NVS
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printf("Updating restart counter in NVS ... ");
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restart_counter++;
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err = nvs_set_i32(handle_to_settings, "restart_conter", restart_counter);
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printf((err != ESP_OK) ? "Failed!\n" : "OK\n");
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// Close the NVS
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nvs_close(handle_to_settings);
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// Restart module
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for (int i = 10; i >= 0; i--) {
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printf("Restarting in %d seconds...\n", i);
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vTaskDelay(1000 / portTICK_RATE_MS);
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}
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printf("Restarting now.\n");
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fflush(stdout);
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system_restart();
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}
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