Store app/dev EUI/key in NVS

.vscode/c_cpp_properties.json

@@ -12,6 +12,7 @@
                 "${IDF_PATH}/components/log/include",
                 "${IDF_PATH}/components/lwip/include/lwip",
                 "${IDF_PATH}/components/lwip/include/lwip/port",
+                "${IDF_PATH}/components/nvs_flash/include",
                 "${IDF_PATH}/components/soc/include",
                 "${IDF_PATH}/components/soc/esp32/include",
                 "${IDF_PATH}/components/tcpip_adapter/include",

examples/hello_world/main/main.cpp

@@ -11,6 +11,7 @@
 
 #include "freertos/FreeRTOS.h"
 #include "esp_event.h"
+#include "nvs_flash.h"
 
 #include "TheThingsNetwork.h"
 
@@ -33,15 +34,12 @@ const unsigned TX_INTERVAL = 30;
 static uint8_t msgData[] = "Hello, world";
 
 
-void send_messages(void* pvParameter)
+void sendMessages(void* pvParameter)
 {
     while (1) {
         printf("Sending message...\n");
         TTNResponseCode res = ttn.transmitBytes(msgData, sizeof(msgData) - 1);
-        if (res == kTTNSuccessfulTransmission)
+        printf(res == kTTNSuccessfulTransmission ? "Message sent.\n" : "Transmission failed.\n");
-            printf("Message sent.\n");
-        else
-            printf("Transmission failed.\n");
 
         vTaskDelay(TX_INTERVAL * 1000 / portTICK_PERIOD_MS);
     }
@@ -49,7 +47,13 @@ void send_messages(void* pvParameter)
 
 extern "C" void app_main(void)
 {
-    gpio_install_isr_service(ESP_INTR_FLAG_IRAM);
+    esp_err_t err;
+    // Initialize the GPIO ISR handler service
+    err = gpio_install_isr_service(ESP_INTR_FLAG_IRAM);
+    ESP_ERROR_CHECK(err);
+    // Initialize the NVS (non-volatile storage) for saving and restoring the keys
+    err = nvs_flash_init();
+    ESP_ERROR_CHECK(err);
 
     // Initialize SPI bus
     spi_bus_config_t spi_bus_config;
@@ -61,15 +65,21 @@ extern "C" void app_main(void)
     spi_bus_config.max_transfer_sz = 0;
 
     esp_err_t ret = spi_bus_initialize(HSPI_HOST, &spi_bus_config, 1);
-    assert(ret == ESP_OK);
+    ESP_ERROR_CHECK(err);
 
     ttn.configurePins(HSPI_HOST, 18, TTN_NOT_CONNECTED, 14, 26, 33);
 
+    // The below line can be commented after the first run as the data is saved in NVS
     ttn.provision(devEui, appEui, appKey);
 
     printf("Joining...\n");
-    ttn.join();
+    if (ttn.join())
-    printf("Joined.\n");
+    {
-
+        printf("Joined.\n");
-    xTaskCreate(send_messages, "send_messages", 1024 * 4, (void* )0, 3, NULL);
+        xTaskCreate(sendMessages, "send_messages", 1024 * 4, (void* )0, 3, NULL);
+    }
+    else
+    {
+        printf("Join failed. Goodbye\n");
+    }
 }

examples/send_recv/Makefile

@@ -1,3 +1,3 @@
-PROJECT_NAME := hello_world
+PROJECT_NAME := send_recv
 
 include $(IDF_PATH)/make/project.mk

examples/send_recv/main/main.cpp

@@ -6,11 +6,12 @@
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
- * Sample program showing how to send a test message every 30 second.
+ * Sample program showing how to send and receive messages.
  *******************************************************************************/
 
 #include "freertos/FreeRTOS.h"
 #include "esp_event.h"
+#include "nvs_flash.h"
 
 #include "TheThingsNetwork.h"
 
@@ -38,10 +39,7 @@ void sendMessages(void* pvParameter)
     while (1) {
         printf("Sending message...\n");
         TTNResponseCode res = ttn.transmitBytes(msgData, sizeof(msgData) - 1);
-        if (res == kTTNSuccessfulTransmission)
+        printf(res == kTTNSuccessfulTransmission ? "Message sent.\n" : "Transmission failed.\n");
-            printf("Message sent.\n");
-        else
-            printf("Transmission failed.\n");
 
         vTaskDelay(TX_INTERVAL * 1000 / portTICK_PERIOD_MS);
     }
@@ -57,7 +55,13 @@ void messageReceived(const uint8_t* message, size_t length, port_t port)
 
 extern "C" void app_main(void)
 {
-    gpio_install_isr_service(ESP_INTR_FLAG_IRAM);
+    esp_err_t err;
+    // Initialize the GPIO ISR handler service
+    err = gpio_install_isr_service(ESP_INTR_FLAG_IRAM);
+    ESP_ERROR_CHECK(err);
+    // Initialize the NVS (non-volatile storage) for saving and restoring the keys
+    err = nvs_flash_init();
+    ESP_ERROR_CHECK(err);
 
     // Initialize SPI bus
     spi_bus_config_t spi_bus_config;
@@ -68,18 +72,24 @@ extern "C" void app_main(void)
     spi_bus_config.quadhd_io_num = -1;
     spi_bus_config.max_transfer_sz = 0;
 
-    esp_err_t ret = spi_bus_initialize(HSPI_HOST, &spi_bus_config, 1);
+    err = spi_bus_initialize(HSPI_HOST, &spi_bus_config, 1);
-    assert(ret == ESP_OK);
+    ESP_ERROR_CHECK(err);
 
     ttn.configurePins(HSPI_HOST, 18, TTN_NOT_CONNECTED, 14, 26, 33);
 
+    // The below line can be commented after the first run as the data is saved in NVS
     ttn.provision(devEui, appEui, appKey);
 
     ttn.onMessage(messageReceived);
 
     printf("Joining...\n");
-    ttn.join();
+    if (ttn.join())
-    printf("Joined.\n");
+    {
-
+        printf("Joined.\n");
-    xTaskCreate(sendMessages, "send_messages", 1024 * 4, (void* )0, 3, NULL);
+        xTaskCreate(sendMessages, "send_messages", 1024 * 4, (void* )0, 3, NULL);
+    }
+    else
+    {
+        printf("Join failed. Goodbye\n");
+    }
 }

include/TheThingsNetwork.h

@@ -90,7 +90,10 @@ public:
     /**
      * @brief Sets the information needed to activate the device via OTAA, without actually activating.
      * 
-     * The provided EUIs and key are saved in non-volatile memory. Call join() without arguments to activate.
+     * The provided device EUI, app EUI and app key are saved in non-volatile memory. Before
+     * this function is called, 'nvs_flash_init' must have been called once.
+     * 
+     * Call join() without arguments to activate.
      * 
      * @param devEui  Device EUI (16 character string with hexadecimal data)
      * @param appEui  Application EUI of the device (16 character string with hexadecimal data)
@@ -101,9 +104,9 @@ public:
     bool provision(const char *devEui, const char *appEui, const char *appKey);
 
     /**
-     * @brief Set the EUIs and keys and activate the device via OTAA.
+     * @brief Set the device EUI, app EUI and app key and activate the device via OTAA.
      * 
-     * The EUIs and key are NOT saved in non-volatile memory.
+     * The device EUI, app EUI and app key are NOT saved in non-volatile memory.
      * 
      * The function blocks until the activation has completed or failed.
      * 
@@ -119,6 +122,7 @@ public:
      * @brief Activate the device via OTAA.
      * 
      * The app EUI, app key and dev EUI must already have been provisioned by a call to 'provision()'.
+     * Before this function is called, 'nvs_flash_init' must have been called once.
      * 
      * The function blocks until the activation has completed or failed.
      * 
@@ -160,11 +164,23 @@ public:
      */
     void onMessage(TTNMessageCallback callback);
 
+    /**
+     * @brief Checks if device EUI, app EUI and app key have been stored in non-volatile storage
+     * or have been provided as by a call to 'join(const char*, const char*, const char*)'.
+     * 
+     * @return true   if they are stored, complete and of the correct size
+     * @return false  otherwise
+     */
+    bool isProvisioned();
 
 private:
     TTNMessageCallback messageCallback;
+    bool haveKeys;
 
+    bool joinCore();
     bool decodeKeys(const char *devEui, const char *appEui, const char *appKey);
+    bool saveKeys();
+    bool restoreKeys(bool silent);
 };
 
 #endif

src/TheThingsNetwork.cpp

@@ -11,6 +11,7 @@
 
 #include "freertos/FreeRTOS.h"
 #include "esp_event.h"
+#include "nvs_flash.h"
 #include "TheThingsNetwork.h"
 #include "esp_log.h"
 #include "oslmic.h"
@@ -26,6 +27,10 @@ enum ClientAction
 };
 
 static const char *TAG = "ttn";
+static const char *NVS_FLASH_PARTITION = "ttn";
+static const char *NVS_FLASH_KEY_DEV_EUI = "devEui";
+static const char *NVS_FLASH_KEY_APP_EUI = "appEui";
+static const char *NVS_FLASH_KEY_APP_KEY = "appKey";
 
 static TheThingsNetwork* ttnInstance;
 static uint8_t devEui[8];
@@ -35,6 +40,8 @@ static QueueHandle_t resultQueue;
 static ClientAction clientAction = eActionUnrelated;
 
 
+static bool readNvsValue(nvs_handle handle, const char* key, uint8_t* data, size_t expectedLength, bool silent);
+static bool writeNvsValue(nvs_handle handle, const char* key, const uint8_t* data, size_t len);
 static bool hexStringToBin(const char *hex, uint8_t *buf, int len);
 static int hexTupleToByte(const char *hex);
 static int hexDigitToVal(char ch);
@@ -42,6 +49,7 @@ static void swapByteOrder(uint8_t* buf, int len);
 
 
 TheThingsNetwork::TheThingsNetwork()
+    : messageCallback(NULL), haveKeys(false)
 {
     ASSERT(ttnInstance == NULL);
     ttnInstance = this;
@@ -67,7 +75,7 @@ void TheThingsNetwork::configurePins(spi_host_device_t spi_host, uint8_t nss, ui
     reset();
 
     resultQueue = xQueueCreate(12, sizeof(int));
-    assert(resultQueue != NULL);
+    ASSERT(resultQueue != NULL);
     hal_startBgTask();
 }
 
@@ -80,11 +88,16 @@ void TheThingsNetwork::reset()
 
 bool TheThingsNetwork::provision(const char *devEui, const char *appEui, const char *appKey)
 {
-    return decodeKeys(devEui, appEui, appKey);
+    if (!decodeKeys(devEui, appEui, appKey))
+        return false;
+    
+    return saveKeys();
 }
 
 bool TheThingsNetwork::decodeKeys(const char *devEui, const char *appEui, const char *appKey)
 {
+    haveKeys = false;
+
     if (strlen(devEui) != 16 || !hexStringToBin(devEui, ::devEui, 8))
     {
         ESP_LOGW(TAG, "Invalid device EUI: %s", devEui);
@@ -107,6 +120,7 @@ bool TheThingsNetwork::decodeKeys(const char *devEui, const char *appEui, const
         return false;
     }
 
+    haveKeys = true;
     return true;
 }
 
@@ -115,11 +129,28 @@ bool TheThingsNetwork::join(const char *devEui, const char *appEui, const char *
     if (!decodeKeys(devEui, appEui, appKey))
         return false;
     
-    return join();
+    return joinCore();
 }
 
 bool TheThingsNetwork::join()
 {
+    if (!haveKeys)
+    {
+        if (!restoreKeys(false))
+            return false;
+    }
+
+    return joinCore();
+}
+
+bool TheThingsNetwork::joinCore()
+{
+    if (!haveKeys)
+    {
+        ESP_LOGW(TAG, "Device EUI, App EUI and/or App key have not been provided");
+        return false;
+    }
+
     hal_enterCriticalSection();
     clientAction = eActionJoining;
     LMIC_startJoining();
@@ -173,6 +204,120 @@ void TheThingsNetwork::onMessage(TTNMessageCallback callback)
     messageCallback = callback;
 }
 
+bool TheThingsNetwork::saveKeys()
+{
+    bool result = false;
+
+    nvs_handle handle = 0;
+    esp_err_t res = nvs_open(NVS_FLASH_PARTITION, NVS_READWRITE, &handle);
+    if (res == ESP_ERR_NVS_NOT_INITIALIZED)
+    {
+        ESP_LOGW(TAG, "NVS storage is not initialized. Call 'nvs_flash_init()' first.");
+        goto done;
+    }
+    ESP_ERROR_CHECK(res);
+    if (res != ESP_OK)
+        goto done;
+
+    if (!writeNvsValue(handle, NVS_FLASH_KEY_DEV_EUI, ::devEui, sizeof(::devEui)))
+        goto done;
+        
+    if (!writeNvsValue(handle, NVS_FLASH_KEY_APP_EUI, ::appEui, sizeof(::appEui)))
+        goto done;
+        
+    if (!writeNvsValue(handle, NVS_FLASH_KEY_APP_KEY, ::appKey, sizeof(::appKey)))
+        goto done;
+
+    res = nvs_commit(handle);
+    ESP_ERROR_CHECK(res);
+    
+    result = true;
+    ESP_LOGI(TAG, "Dev and app EUI and app key saved in NVS storage");
+
+done:
+    nvs_close(handle);
+    return result;
+}
+
+bool TheThingsNetwork::restoreKeys(bool silent)
+{
+    haveKeys = false;
+    
+    nvs_handle handle = 0;
+    esp_err_t res = nvs_open(NVS_FLASH_PARTITION, NVS_READONLY, &handle);
+    if (res == ESP_ERR_NVS_NOT_FOUND)
+        return false; // partition does not exist yet
+    if (res == ESP_ERR_NVS_NOT_INITIALIZED)
+    {
+        ESP_LOGW(TAG, "NVS storage is not initialized. Call 'nvs_flash_init()' first.");
+        goto done;
+    }
+    ESP_ERROR_CHECK(res);
+    if (res != ESP_OK)
+        goto done;
+
+    if (!readNvsValue(handle, NVS_FLASH_KEY_DEV_EUI, ::devEui, sizeof(::devEui), silent))
+        goto done;
+
+    if (!readNvsValue(handle, NVS_FLASH_KEY_APP_EUI, ::appEui, sizeof(::appEui), silent))
+        goto done;
+
+    if (!readNvsValue(handle, NVS_FLASH_KEY_APP_KEY, ::appKey, sizeof(::appKey), silent))
+        goto done;
+
+    haveKeys = true;
+    ESP_LOGI(TAG, "Dev and app EUI and app key have been restored from NVS storage");
+
+done:
+    nvs_close(handle);
+    return haveKeys;
+}
+
+bool TheThingsNetwork::isProvisioned()
+{
+    if (haveKeys)
+        return true;
+    
+    return restoreKeys(true);
+}
+
+bool readNvsValue(nvs_handle handle, const char* key, uint8_t* data, size_t expectedLength, bool silent)
+{
+    size_t size = expectedLength;
+    esp_err_t res = nvs_get_blob(handle, key, data, &size);
+    if (res == ESP_OK && size == expectedLength)
+        return true;
+
+    if (res == ESP_OK && size != expectedLength)
+    {
+        if (!silent)
+            ESP_LOGW(TAG, "Invalid size of NVS data for %s", key);
+        return false;
+    }
+
+    if (res == ESP_ERR_NVS_NOT_FOUND)
+    {
+        if (!silent)
+            ESP_LOGW(TAG, "No NVS data found for %s", key);
+        return false;
+    }
+    
+    ESP_ERROR_CHECK(res);
+    return false;
+}
+
+bool writeNvsValue(nvs_handle handle, const char* key, const uint8_t* data, size_t len)
+{
+    uint8_t buf[16];
+    if (readNvsValue(handle, key, buf, len, true) && memcmp(buf, data, len) == 0)
+        return true; // unchanged
+    
+    esp_err_t res = nvs_set_blob(handle, key, data, len);
+    ESP_ERROR_CHECK(res);
+
+    return res == ESP_OK;
+}
+
 
 // --- LMIC functions ---
 

src/hal_esp32.c

@@ -84,7 +84,7 @@ static void hal_io_init()
     }
 
     dio_queue = xQueueCreate(12, sizeof(queue_item_t));
-    assert(dio_queue != NULL);
+    ASSERT(dio_queue != NULL);
 
     gpio_pad_select_gpio(lmic_pins.dio0);
     gpio_set_direction(lmic_pins.dio0, GPIO_MODE_INPUT);
@@ -151,8 +151,8 @@ static void collect_spi_result()
 
     spi_transaction_t* trx;
     esp_err_t err = spi_device_get_trans_result(spi_handle, &trx, 100 / portTICK_PERIOD_MS);
-    assert(err == ESP_OK);
+    ESP_ERROR_CHECK(err);
-    assert(trx == spi_trx_queue + tail);
+    ASSERT(trx == spi_trx_queue + tail);
     spi_num_outstanding_trx--;
 }
 
@@ -163,7 +163,7 @@ static void submit_spi_trx()
 
     int head = spi_trx_queue_head;
     esp_err_t err = spi_device_queue_trans(spi_handle, spi_trx_queue + head, 100 / portTICK_PERIOD_MS);
-    assert(err == ESP_OK);
+    ESP_ERROR_CHECK(err);
     spi_num_outstanding_trx++;
 
     head++;
@@ -185,7 +185,7 @@ static void hal_spi_init()
     };
 
     esp_err_t ret = spi_bus_add_device(lmic_pins.spi_host, &spi_device_intf_config, &spi_handle);
-    assert(ret == ESP_OK);
+    ESP_ERROR_CHECK(ret);
 
     ESP_LOGI(TAG, "SPI initialized");
 }
@@ -459,5 +459,5 @@ void hal_startBgTask() {
 void hal_failed(const char *file, u2_t line)
 {
     ESP_LOGE(TAG, "%s:%d", file, line);
-    assert(0);
+    ASSERT(0);
 }