Sony Spresense + Arduino: connect a W5500 based Ethernet if

Question

I try to use the Spresense board to build a NTP server.
Ethernet should be done with W5500 chip connected over SPI. Seems that the Arduino Ethernet library got a problem with the Apresense SPI library.

Someone out there who tried this already and have some ideas on it?

Code from Ethernet DhcpAddressPrinter example compiles just fine after changing Arduino/libraries/Ethernet/src/EthernetClient.cpp in Line 51

if (ip == IPAddress((uint32_t)0) || ip == IPAddress(0xFFFFFFFFul)) return 0;

I always get the message from the serial terminal that "Ethernet shield was not found". The W5500 PCB should not be the problem as it works on a normal Arduino Uno just fine. (It is not the original Arduino Ethernet shield, as this shield uses the ICSP header which is not present on Spresense board)

The Arduino IDE is 1.8.8

Answer 1

Hardware Problem solved: The W5500 and Spresense want the I/O level jumper on the board set to 3.3V. Ethernet lib seems to work now, at least on the SPI. I´m looking forward to work on the software now.