W5500 on Arduino |
Voltage Divider |
I had used a bread board shield to configure a wireless module before and that worked fine.
Then I used the same shield to drive the W5500. The wireless module was driven by a voltage divider to drop the levels suitable for it. The value for R1 was 10K and R2 was 15K. The module plugs in a socket and next to socket are posts. I used the posts to wire up the Ethernet module.
Using a logic analyser, everything seemed fine, and later I found out it was because I connected the analyser to the 5V side and not the voltage divided side.
Out of desperation I read the data sheet for the W5500, I knew it ran on 3.3V and that is why I used the divider, but I found out that it could tolerate 5V levels. So I wired it up directly and it worked!!
It appears that the divider did not provide enough current to drive the W5500. You can use level shifters , maybe a lower resistance divider, or directly drive with 5V.
Hope this can save time for somebody else.