我仔细遵循（重复两次）所有先决条件并成功连接到 Azure IoT Hub。已上传入门示例的设备代码（将 IoT DevKit 传感器数据发送到 IoT 中心）。我在最后一步收到以下错误。
[Starting] Opening the serial port - COM4
[Info] Opened the serial port - COM4
2019-02-09 06:31:12 INFO: >>>IoTHubClient_LL_SendEventAsync accepted message for transmission to IoT Hub.
2019-02-09 06:31:17 ERROR: File:C:\Users\v-zuhu\AppData\Local\Arduino15\packages\AZ3166\hardware\stm32f4\1.6.0\cores\arduino\azure-iot-sdk-c\iothub_client\src\iothubtransport_mqtt_common.c Func:mqtt_operation_complete_callback Line:1724, Connection Not Accepted: 0x5: Not Authorized
[Done] Closed the serial port
我尝试从头开始重新创建示例，并在 DevKitDPS.ino 上传期间注意到以下类型的多个错误：
..\AppData\Local\Arduino15\packages\AZ3166\hardware\stm32f4\1.6.1\system/platform/toolchain.h:23:2: warning: #warning toolchain.h has been replaced by mbed_toolchain.h, please update to mbed_toolchain.h [since mbed-os-5.3] [-Wcpp]
#warning toolchain.h has been replaced by mbed_toolchain.h, please update to mbed_toolchain.h [since mbed-os-5.3]
..\examples\devkit_dps\Device\DevKitDPS.ino:12:32: warning: ISO C++ forbids converting a string constant to 'char*' [-Wwrite-strings]
char* Global_Device_Endpoint = "global.azure-devices-provisioning.net";
研究了这个问题，发现了以下链接：
https ://github.com/ARMmbed/mbed-os/issues/3876
toolchain.h has been added by mbed_toolchain.h
我不知道如何进行，任何指导将不胜感激。