W5500-EVB-Pico multiple simultaneous TCP connections

Question

I am creating two different TCP connections both to the W5500. The first one succeeds but the second one fails: Connection Refused. According to this documentation https://os.mbed.com/teams/WIZnet/code/Ethernet/docs/ee0f7508fb5c/group__WIZnet__socket__APIs.html#ga8cc0a2074b3aae98a132c1ae3c51188f I can just add multiple sockets to the same port. I would expect that the first connection will be handled by the first socket and the second one will be handled by the second one. If I understood correctly modifying the example tcp loopback code like this /* Infinite loop */ while (1) { for (int i = 0; i < 4; i++) { /* TCP server loopback test */ if ((retval = loopback_tcps(SOCKET_LOOPBACK, g_loopback_buf, PORT_LOOPBACK)) < 0) { printf(" Loopback error : %d
", retval); while (1) ; } } } should make the first 4 sockets handle TCP connections. But as I said, it does not work. Any ideas? How do I use multiple sockets for multiple TCP connections?

TheoIm · Answer

Hello, here is the response. It seems there is an error in your code. The first argument of loopback_tcps, which is the socket number, should be assigned as i. However, your code does not vary the socket number within the for loop. Please check your code.