[lwip-users] LWIP never tries to send a packet?

[Chris Seto]

Hi,

I'm using LwIP 2.0 running on an STM32F4 with a TI TLK110 ethernet PHY. I've written the driver for the PHY and corrected the definitions within the STM32 HAL such that the PHY is initialized correctly. When low_level_init() returns, the link is guaranteed physically up. 

I'm having an issue where it doesn't seem like LwIP is ever trying to send packets. I put printf("RX\r\n"); and printf("TX\r\n"); calls in my ethernetif.c handlers, and while RX periodically is called, TX is /never/ called. Even if I try to open a TCP socket, and even if I try dhcp_start().

I'm sure this is some kind of minor config issue. Any advice?

Debugging is enabled, and I see a bunch of "etharp_timer" at about 2hz or so, but nothing else. Shouldn't I at least expect to see a DHCP discover packet sent?

Code here:

ethernetif.c

https://pastebin.com/eXGyDWJX

lwipopts.h

https://pastebin.com/ZTmmG43P

Networking.c

https://pastebin.com/20DN07dy

Main loop:

while (1)

{

HAL_Delay(50);

LedToggle(LED_1);

LedToggle(LED_2);

NetworkingUpdate();

}

Thanks!