How to upload a file to a server via UDP? Help needed.

Kronosss wrote:

I started playing around with the WiFi module.

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Which one specifically?

Kronosss wrote:

I wrote the program

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Although a snippet of 'problematic' code would be appreciated.

Kronosss wrote:

But how to create a second connection at the same time for a port

AT+CIPSEND: " This command can only be used in transparent transmission mode which requires single connection "
Try with AT+CIPSENDEX. Also, if you have set "AT+CIPMUX=0" then it is "single connection mode"

Documentation: https://www.espressif.com/sites/default/files...entation/4a-esp8266_at_instruction_set_en.pdf

Kronosss wrote:

And how to switch between these ports?

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By "link ID" in AT+CIPSENDEX.

If you want to send data from the ESP to the server in non-blocking mode, you should use the command AT+CIPSENDBUF . You specify the size of this data and then enter it. The data goes into a buffer from which it will be progressively sent - you can continuously check the status of the sending of this data with the command AT+CIPBUFSTATUS . During this time you can also execute other AT commands, including triggering the sending of other data.

Unlike AT+CIPSENDBUF, the command AT+CIPSENDEX is a blocking function. You will not be able to execute other commands until the send is complete.

For multiple TCP connections ( AT+CIPMUX=1 ), use a different syntax for the AT+CIPSTART command:
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where link ID is the identifier of the link in question and can then be used in AT+CIPSEND, AT+CIPSENDEX or AT+CIPSENDBUF commands

All of the above is described in detail in the documentation I provided a link to in post #4. In addition, I am attaching the document "ESP8266 AT Command Examples", where it is explained how to create Single and Multiple connections for TCP and UDP.