ESP32-DevKitC : "Operating mode must not be set while SNTP client is running" issue. about esp-azure

[JonS9999]

FYI, I was able to fix the problem based on the information I found here:

VSChina/ESP32_AzureIoT_Arduino#5

On Jul 19, 2018, lirenhe suggested adding the following code to SNTP_Init() in sntp_lwip.c :

if ( sntp_enabled() ) {
sntp_stop();
}

This did fix the problem. Basically, SNTP_Init() would fail the second time it was called. The above code gracefully terminates/cleans up the existing SNTP code which allows it to be restarted successfully.

I merged that code into this file :

C:\Users...\AppData\Local\Arduino15\packages\esp32\hardware\esp32\1.0.1\libraries\AzureIoT\src\az_iot\c-utility\pal\lwip\sntp_lwip.c

I will try your examples to see if I have any better luck (without needing to modify any library code).

Thank you for your time. :-)

-Jon

[JonS9999]

I forgot to mention that when the code detects that the WiFI has dropped, it will execute an Esp32MQTTClient_Close() call, but that errors out since there is no active WiFi/Azure connection.

[JonS9999]

No responses?? :-? :-(

[jitin17]

Are you using Arduino based Azure library?
I don't find Esp32MQTTClient_Close() API in this repository.

[JonS9999]

I thought I was, but honestly, I'm not 100% sure. In my attempts to get my ESP32 working with Azure, I tried a number of different libraries until I found one that worked. According to the Arduino IDE, I have the following Azure related libraries installed:

• AzureIoTHub (by Microsoft, ver 1.0.45)
• AzureIoTHubMQTTClient (by Andri Yadi, ver 0.2.3)
• AzureIoTProtocol_MQTT (by Microsoft, ver 1.0.45)
• AzureIoTUtility (by Microsoft, ver 1.0.45)

Under the File -> Examples menu, I started with ESP32 Azure IoT Arduino -> SimpleMQTT in order to get something working. Once I had this up and running, I wrote my own, based off of the SimpleMQTT example. This is the example that uses "Esp32MQTTClient.h" and the corresponding Esp32MQTTCLient_xxxx() calls. It doesn't use _Close directly, but it's in the include file, so I thought I'd give it a try.

Under the File -> Examples -> INCOMPATIBLE menu, there are several Azure IoT example -- I did not try any of these.

[jitin17]

@JonS9999 Can you try the samples given at examples directory of this repository?

[mahavirj]

@JonS9999 I will close this issue as problem is fixed. If you still find any problem, please feel free to raise new issue.