Posts: 4
Joined: Sun Jun 16, 2019 3:50 pm


Sun Jun 16, 2019 3:57 pm

Hi everyone,

I am working on a new project with the CM3+ and have used the LAN9514 chip in my design, but for some reason when I plug in an ethernet cable I get no lights on the ethernet port and the device is not pulling an IP address. I need help figuring out how to troubleshoot the device from here.

When I run ifconfig, I do see eth0 listed as an interface, but with no IP address associated:

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eth0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
         ether b8:27:eb:c3:42:a7 . txqueuelen  (Ethernet)
         RX packets 0  bytes 0 (0.0 B)
When running lsusb I see the following:

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Bus 001 Device 004: ID 046d:c534 Logitech, Inc. Unifying Receiver
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. SMSC9512/9514 Fast Ethernet Adapter
Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp. SMC9514 Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
So how do I troubleshoot from here? Is there some sort of configuration I need to do to the CM3+ to enable the ethernet interface?


Posts: 2
Joined: Wed Jun 19, 2019 12:22 am

Re: LAN9514

Wed Jun 19, 2019 12:30 am

Hi Newpi,

A schematic would be helpful. I can say from personal experience that not triple checking the pin outs on the magnetics is where I have come unstuck before.

For example ... t/J403.pdf

has about five different options.

But it was not my fault, and I choose to blame KiCad :)

Posts: 4
Joined: Sun Jun 16, 2019 3:50 pm

Re: LAN9514

Sun Jul 14, 2019 7:44 pm

As it turns out, I was missing the pull-up resistors on the input wires. Soldering these on fixed the problem!

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