I'm starting to work with the NVS on my product and I'm getting an error with trying to retrieve values using nvs_get_blob(), error code being returned is 0x102 ESP_ERR_INVALID_ARG. I'm just starting to use these API's so I admit I'm not familiar with using them yet, but I'm following an example that I found in the examples directory in esp-idf.
I plan to use the NVS for holding some configuration data for the application to use for initialization.
I've started with a couple of simple parameters for the softAP wifi interface. I've created a structure that holds ssid and password.
//header file
typedef struct storedConfig
{
char ssidVal[20];
char pass[20];
}storedConfig_t;
//c file
storedConfig_t cnf={
.ssidVal="ESP32",
.pass="password",
};
storedConfig_t *pcnf;
My API usage looks like the following;
// Step 1. Open the file
err = nvs_open(STORAGE_NAMESPACE, NVS_READWRITE, &my_handle);
if (err != ESP_OK) return err;
//step 2. check to see if the file has been initialized with the SSID key has been written, if not write and commit
size_t required_size = 0; // value will default to 0, if not set yet in NVS
err = nvs_get_blob(my_handle, "ssid", NULL, &required_size);
if (err != ESP_OK && err != ESP_ERR_NVS_NOT_FOUND)
{
printf("opening first time file write init\r\n");
required_size = strlen(cnf.ssidVal);
err = nvs_set_blob(my_handle, "ssid", cnf.ssidVal, required_size);
required_size = strlen(cnf.pass);
err = nvs_set_blob(my_handle, "password", cnf.pass, required_size);
// Commit
err = nvs_commit(my_handle);
if (err != ESP_OK) return err;
}
//step 3. read the previously configured values assuming the file has been written
err = nvs_get_blob(my_handle, "ssid", cnf.ssidVal, &required_size);
printf("get_configuration_values() ssid:%s err:%d reqsize:%d\r\n",cnf.ssidVal,err,(int)required_size);
err = nvs_get_blob(my_handle, "pass", cnf.pass, &required_size);
printf("get_configuration_values() pass:%s err:%d reqsize:%d\r\n",cnf.pass,err,(int)required_size);
//if (err != ESP_OK) return err;
Another question about clearing the entire space to start over, while in development mode
//use the erase all and then close? Doesn't seem to be working.
nvs_erase_all(my_handle);
// Close
nvs_close(my_handle);
I'm hoping someone more familiar with this can spot what I'm doing wrong. Any help is greatly appreciated.
ESP32 nvs_get_blob() help
Re: ESP32 nvs_get_blob() help
I ran your code, and it prints the following:
Note that the error is 0x1102 (not 0x102), which is ESP_ERR_NVS_NOT_FOUND.
Looking at the code, it makes sense, because 'nvs_set_blob' will only get executed iff err != ESP_OK AND err != ESP_ERR_NVS_NOT_FOUND. First nvs_get_blob returns ESP_ERR_NVS_NOT_FOUND, so we skip the part which does nvs_set and try to read again... which fails with the same ESP_ERR_NVS_NOT_FOUND error. So there's something odd with the logic in this code snippet.
Other problems with your code:
- you use "password" key in nvs_set_blob and later you use "pass" key in nvs_get_blob.
- you are not setting required_size variable to the size of destination buffer before your nvs_get_blob calls. What you probably need to do looks like this:
Code: Select all
get_configuration_values() ssid:ESP32 err:0x1102 reqsize:0
get_configuration_values() pass:password err:0x1102 reqsize:0
Looking at the code, it makes sense, because 'nvs_set_blob' will only get executed iff err != ESP_OK AND err != ESP_ERR_NVS_NOT_FOUND. First nvs_get_blob returns ESP_ERR_NVS_NOT_FOUND, so we skip the part which does nvs_set and try to read again... which fails with the same ESP_ERR_NVS_NOT_FOUND error. So there's something odd with the logic in this code snippet.
Other problems with your code:
- you use "password" key in nvs_set_blob and later you use "pass" key in nvs_get_blob.
- you are not setting required_size variable to the size of destination buffer before your nvs_get_blob calls. What you probably need to do looks like this:
Code: Select all
required_size = sizeof(cnf.ssidVal);
err = nvs_get_blob(my_handle, "ssid", cnf.ssidVal, &required_size);
printf("get_configuration_values() ssid:%s err:0x%x reqsize:%d\r\n",cnf.ssidVal,err,(int)required_size);
required_size = sizeof(cnf.pass);
err = nvs_get_blob(my_handle, "password", cnf.pass, &required_size);
printf("get_configuration_values() pass:%s err:0x%x reqsize:%d\r\n",cnf.pass,err,(int)required_size);
Re: ESP32 nvs_get_blob() help
Thank you very much for the help with pointing that out, I'll try what you mentioned here and post back with the results.
Who is online
Users browsing this forum: Bing [Bot], VinayDand and 421 guests