[lwip-users] sys_timeout() handler never being triggered in mqtt.c

[inceljoe]

Good day everybody,

I was trying to use the mqtt functionality which is included in LwIP at LwIP/src/apps/mqtt. I am using LwIP alongside FreeRTOS on a STM32 microcontroller.

The MQTT server requires the client to send a ping packet every few seconds, by reading the code I found out this functionality is implemented with a sys_timeout() at line 1066 in mqtt.c . This is the line in particular:

sys_timeout(MQTT_CYCLIC_TIMER_INTERVAL * 1000, mqtt_cyclic_timer, client);

But the problem is, that the mqtt_cyclic_timer function isn't triggered at all, not even once. I put a breakpoint into it and it was never hit.

The tick source given to the sys_now() works fine and increases by one every millisecond so I have no idea why the sys_timeout() function doesn't run the handler function even once. Can anyone help me? Thanks for your time.