![](/media/cache/img/default_profile.jpg.50x50_q85.jpg)
A simple IoTHub sample using HTTP as transport
Dependencies: EthernetInterface NTPClient iothub_client iothub_http_transport mbed-rtos mbed wolfSSL serializer azure_c_shared_utility
This sample showcases the usage of Azure IoT client libraries with the HTTP transport for sending/receiving raw messages from an IoT Hub.
simplesample_http.c
- Committer:
- AzureIoTClient
- Date:
- 2016-04-24
- Revision:
- 34:e8375a90f09f
- Parent:
- 28:44b1d44d0d3b
- Child:
- 41:4080293252bc
File content as of revision 34:e8375a90f09f:
// Copyright (c) Microsoft. All rights reserved. // Licensed under the MIT license. See LICENSE file in the project root for full license information. #include <stdlib.h> #include <stdio.h> #include <stdint.h> /* This sample uses the _LL APIs of iothub_client for example purposes. That does not mean that HTTP only works with the _LL APIs. Simply changing the using the convenience layer (functions not having _LL) and removing calls to _DoWork will yield the same results. */ #ifdef ARDUINO #include "AzureIoT.h" #else #include "serializer.h" #include "iothub_client_ll.h" #include "iothubtransporthttp.h" #include "azure_c_shared_utility/threadapi.h" #include "azure_c_shared_utility/platform.h" #endif #ifdef MBED_BUILD_TIMESTAMP #include "certs.h" #endif // MBED_BUILD_TIMESTAMP /*String containing Hostname, Device Id & Device Key in the format: */ /* "HostName=<host_name>;DeviceId=<device_id>;SharedAccessKey=<device_key>" */ static const char* connectionString = "[device connection string]"; // Define the Model BEGIN_NAMESPACE(WeatherStation); DECLARE_MODEL(ContosoAnemometer, WITH_DATA(ascii_char_ptr, DeviceId), WITH_DATA(int, WindSpeed), WITH_ACTION(TurnFanOn), WITH_ACTION(TurnFanOff), WITH_ACTION(SetAirResistance, int, Position) ); END_NAMESPACE(WeatherStation); DEFINE_ENUM_STRINGS(IOTHUB_CLIENT_CONFIRMATION_RESULT, IOTHUB_CLIENT_CONFIRMATION_RESULT_VALUES) EXECUTE_COMMAND_RESULT TurnFanOn(ContosoAnemometer* device) { (void)device; (void)printf("Turning fan on.\r\n"); return EXECUTE_COMMAND_SUCCESS; } EXECUTE_COMMAND_RESULT TurnFanOff(ContosoAnemometer* device) { (void)device; (void)printf("Turning fan off.\r\n"); return EXECUTE_COMMAND_SUCCESS; } EXECUTE_COMMAND_RESULT SetAirResistance(ContosoAnemometer* device, int Position) { (void)device; (void)printf("Setting Air Resistance Position to %d.\r\n", Position); return EXECUTE_COMMAND_SUCCESS; } void sendCallback(IOTHUB_CLIENT_CONFIRMATION_RESULT result, void* userContextCallback) { int messageTrackingId = (intptr_t)userContextCallback; (void)printf("Message Id: %d Received.\r\n", messageTrackingId); (void)printf("Result Call Back Called! Result is: %s \r\n", ENUM_TO_STRING(IOTHUB_CLIENT_CONFIRMATION_RESULT, result)); } static void sendMessage(IOTHUB_CLIENT_LL_HANDLE iotHubClientHandle, const unsigned char* buffer, size_t size) { static unsigned int messageTrackingId; IOTHUB_MESSAGE_HANDLE messageHandle = IoTHubMessage_CreateFromByteArray(buffer, size); if (messageHandle == NULL) { printf("unable to create a new IoTHubMessage\r\n"); } else { if (IoTHubClient_LL_SendEventAsync(iotHubClientHandle, messageHandle, sendCallback, (void*)(uintptr_t)messageTrackingId) != IOTHUB_CLIENT_OK) { printf("failed to hand over the message to IoTHubClient"); } else { printf("IoTHubClient accepted the message for delivery\r\n"); } IoTHubMessage_Destroy(messageHandle); } free((void*)buffer); messageTrackingId++; } /*this function "links" IoTHub to the serialization library*/ static IOTHUBMESSAGE_DISPOSITION_RESULT IoTHubMessage(IOTHUB_MESSAGE_HANDLE message, void* userContextCallback) { IOTHUBMESSAGE_DISPOSITION_RESULT result; const unsigned char* buffer; size_t size; if (IoTHubMessage_GetByteArray(message, &buffer, &size) != IOTHUB_MESSAGE_OK) { printf("unable to IoTHubMessage_GetByteArray\r\n"); result = EXECUTE_COMMAND_ERROR; } else { /*buffer is not zero terminated*/ char* temp = malloc(size + 1); if (temp == NULL) { printf("failed to malloc\r\n"); result = EXECUTE_COMMAND_ERROR; } else { EXECUTE_COMMAND_RESULT executeCommandResult; memcpy(temp, buffer, size); temp[size] = '\0'; executeCommandResult = EXECUTE_COMMAND(userContextCallback, temp); result = (executeCommandResult == EXECUTE_COMMAND_ERROR) ? IOTHUBMESSAGE_ABANDONED : (executeCommandResult == EXECUTE_COMMAND_SUCCESS) ? IOTHUBMESSAGE_ACCEPTED : IOTHUBMESSAGE_REJECTED; free(temp); } } return result; } void simplesample_http_run(void) { if (platform_init() != 0) { printf("Failed to initialize the platform.\r\n"); } else { if (serializer_init(NULL) != SERIALIZER_OK) { (void)printf("Failed on serializer_init\r\n"); } else { IOTHUB_CLIENT_LL_HANDLE iotHubClientHandle = IoTHubClient_LL_CreateFromConnectionString(connectionString, HTTP_Protocol); int avgWindSpeed = 10; srand((unsigned int)time(NULL)); if (iotHubClientHandle == NULL) { (void)printf("Failed on IoTHubClient_LL_Create\r\n"); } else { // Because it can poll "after 9 seconds" polls will happen // effectively at ~10 seconds. // Note that for scalabilty, the default value of minimumPollingTime // is 25 minutes. For more information, see: // https://azure.microsoft.com/documentation/articles/iot-hub-devguide/#messaging unsigned int minimumPollingTime = 9; ContosoAnemometer* myWeather; if (IoTHubClient_LL_SetOption(iotHubClientHandle, "MinimumPollingTime", &minimumPollingTime) != IOTHUB_CLIENT_OK) { printf("failure to set option \"MinimumPollingTime\"\r\n"); } #ifdef MBED_BUILD_TIMESTAMP // For mbed add the certificate information if (IoTHubClient_LL_SetOption(iotHubClientHandle, "TrustedCerts", certificates) != IOTHUB_CLIENT_OK) { (void)printf("failure to set option \"TrustedCerts\"\r\n"); } #endif // MBED_BUILD_TIMESTAMP myWeather = CREATE_MODEL_INSTANCE(WeatherStation, ContosoAnemometer); if (myWeather == NULL) { (void)printf("Failed on CREATE_MODEL_INSTANCE\r\n"); } else { if (IoTHubClient_LL_SetMessageCallback(iotHubClientHandle, IoTHubMessage, myWeather) != IOTHUB_CLIENT_OK) { printf("unable to IoTHubClient_SetMessageCallback\r\n"); } else { myWeather->DeviceId = "myFirstDevice"; myWeather->WindSpeed = avgWindSpeed + (rand() % 4 + 2); { unsigned char* destination; size_t destinationSize; if (SERIALIZE(&destination, &destinationSize, myWeather->DeviceId, myWeather->WindSpeed) != IOT_AGENT_OK) { (void)printf("Failed to serialize\r\n"); } else { IOTHUB_MESSAGE_HANDLE messageHandle = IoTHubMessage_CreateFromByteArray(destination, destinationSize); if (messageHandle == NULL) { printf("unable to create a new IoTHubMessage\r\n"); } else { if (IoTHubClient_LL_SendEventAsync(iotHubClientHandle, messageHandle, sendCallback, (void*)1) != IOTHUB_CLIENT_OK) { printf("failed to hand over the message to IoTHubClient"); } else { printf("IoTHubClient accepted the message for delivery\r\n"); } IoTHubMessage_Destroy(messageHandle); } free(destination); } } /* wait for commands */ while (1) { IoTHubClient_LL_DoWork(iotHubClientHandle); ThreadAPI_Sleep(100); } } DESTROY_MODEL_INSTANCE(myWeather); } IoTHubClient_LL_Destroy(iotHubClientHandle); } serializer_deinit(); } platform_deinit(); } }