I am using EC25-G module & successfully able to publish and subscribe messages to Azure IoT Hub via MQTT.
I have configured the msg_recv_mode = 1 (MQTT message received from server will not be contained in URC.). Hence I am reading the data received from buffer.
The issue I have observed that when the server send the bulky data say 8532 bytes then one EC25-G device it received fully (8532 bytes ) but on another device it is received partially ( received only last 4448 bytes ).
This observation remains same even though did testing several times.
Firmware version of both the modules : EG25GGDR07A08M2G
note that both the devices having EC25-G module has exactly the same firmware & hardware.
What is the reason behind that ? what is the recommended way of receiving the bulky data of size > 8KB via MQTT ?
One important point I have observed while analyzing the above issue , EC25 module adds ‘OK\r’ char in the data. Because of this application logic exit from the receive function assuming that full data is received .
Refer attached image where it clearly observed that OK\r is added by module. Note that payload is JSON so there is no chance that special char is added by server .
Also the same data is successfully received on another module and PC based software.
Will the “OK” character you mentioned appear on both normal and abnormal receiving modules?
This ‘OK\r’ observed only on abnormal module.
What is the current probability of this problem occurring? How many devices have this problem?
This happens every time on the problematic / abnormal device. Till now we observed this on two devices.
Here interesting to note that the device which is working OK is in India and the two problematic devices are at same location in USA.
Do you want to try another MQTT server?
Data is received from the Microsoft Azure IoT hub for all the devices.
Hi @gaurav.patni
Thank you for the detailed information you provided. Currently, the situation you mentioned did not occur when I tested it locally using the AWS server. Could you please help me capture the problem log? We would like to check the log to see if we can find the cause of the problem.
Please tell me whether the module is used under Windows system or Linux system. I will give you the log capture tool for the corresponding system.
Note that we are doing our development on windows based PC . Note that the given EC25-G module is soldered on board & its UART port is connected to host microcontroller .
Note that this problem is not observed on all the modules we have hence it may not be possible to replicate at your end .
Is there any way to troubleshoot using AT command using soldered module ?
This problem is critical as production is on hold
Note: while sharing the PC logging tool please explain the connection & steps to extract the logs
Hi @gaurav.patni
Can you tell me the name of your company and where the equipment is used? I need this information to create an internal work order to further follow up on this issue.
Hi @gaurav.patni
You can lead out the following four pins, connect the USB head, and then connect it to the computer. I will send you the log capture tool. After you connect to the log capture tool, reproduce the problem and capture the log. Then send me the problem log and tell me the time of the problem. I will take a look at the detailed analysis of the log.
