Connecting two W5500 via UDP results in PHY link off

Question

Hello, I want to connect two STM32F4 and to communicate via UDP. At the moment I only want to send data from one to another mcu. I have tested tx and rx communication separately with PC - python scripts and I it works as expected. Also, I trace communication with Wireshark. Now it comes moment where I need to connect mcus with ethernet cable so no more connection with PC. I have problem that PHY link is off on both W5500 and I don’t understand what can be issue. Mac, IP address, port are properly configured. Does anybody have idea what can be problem? With function wizphy_getphylink() and with orange/green no activity I notice this problem. Here is init of UDP: W5500_spi_Hw_Rst(); // reset W5500 by activating nRST pin W5500_spi_Reg_Spi_Cb_Funcs(); // register different SPI callback functions for wiznet API lib W5500_spi_Init_Socket_Buff_Size(); // initialize tx and rx buffer size for each socket W5500_spi_Config_Net_Params(); // configure network parameters W5500_spi_Config_Net_Phy(); // configure network phy (physical layer) W5500_spi_Init_UDP_Socket(); // get free socket and declare it to be UDP type

Eugeny · Answer

Chip is not MDIX thus you may try using other type of cable.