¿W5500 / Ethernet Shield 2 How to make it work without pin 10 (SCSn)

Question

Hello friends, after reviewing the information that is available, I do not see anything that will ruin this. Is it possible to use the Ethernet Shield by pulling the SCSn pin of the w5500 chip to negative? According to the pdf the chip W5500 can work as it is now with the active signal from scsn controlled by the mega for example, but also putting it to negative and mode (Fixed Length Data Mode (SCSn is always connected by Ground) I want to use the network module without the sd or any other device on the spi bus. With which the selection pin(SCSn) would not be necessary. Someone knows how to make it work without pin SCSn I am using the arduino ethernet.h library but I do not know how do to put the w5500 in FDM mode Greetings and thank you

irina · Answer

Hi~ Doelectric_Domotica you’re right. The SCSn signal should be tied to Low(Always connected to GND). And , Data Phase length is controlled by OM[1:0] value (‘01’ / ‘10’ / ‘11’) which is the SPI Operation Mode Bits of the Control Phase. Unfortunately, you can’t use the FDM mode using the Arduino Ethernet Library. If you want to use the FDM, you should modify the Ethernet Library(I don’t know if I can fix that.) thanks,

Doelectric Domotica · Answer

Can do it?

Doelectric Domotica · Answer

There is some “C” or C++ library that is not Arduino that uses the format FDM?

Doelectric Domotica · Answer

Hello, There is some “C” or C++ library that is not Arduino that uses the format FDM?

Mxyxixptlick · Answer

I haven’t tried this, but suspect you can edit w5500.cpp and comment out every occurrence of “SPI.endTransaction();” and every occurrence of “SPI.beginTransaction(SPI_ETHERNET_SETTINGS);” EXCEPT the one in W5100Class::init(void). This should leave the SPI connection to the W5500 active at all times.