Using Two Chips Simultaneously

Question

I have two W5500s with different SPIs but on the same host. seems ioLibrary 4.0 does not support instantiation , how can I use two chips independently?

TheoIm · Answer

Hi, There is an STM32 example that demonstrates how to use two W5100S chips with a single MCU. You can refer to the maker site link for detailed implementation. 1 MCU, 2 WIZnet Chips: Dual SPI Networking on STM32 The key difference between the W5100S and W5500 is the number of available sockets, which must be considered in your implementation. The setup itself isn't complex. You can control each chip individually using a dedicated Chip Select (CS) pin, which allows you to operate both chips using a single shared set of functions instead of separate ones. However, you must account for global variables that are socket-number dependent. For example, in iolibrary/Ethernet/socket.c, you'll find definitions like: static uint16_t sock_io_mode = 0; static uint16_t sock_is_sending = 0; static datasize_t sock_remained_size[_WIZCHIP_SOCK_NUM_] = {0, 0, ...}; static uint8_t sock_pack_info[_WIZCHIP_SOCK_NUM_] = {0, 0, ...}; The code snippet I referred to is located in the WIZnet ioLibrary at iolibrary/Ethernet/socket.c. These variables operate independently per socket, either bit-wise or as arrays. Therefore, you must ensure that they are allocated to cover the total number of sockets used across all connected chips. For instance, when using two W5500 chips, you'll have 16 total sockets, so these variables need to be expanded accordingly. The example code already reflects this, so you can use it as a reference during implementation.