Re: [lwip-users] How to send data at a defined time?

[Martin Haupt]

Sergio R. Caprile

Thanks for replying.
I have no RTOS, NO_SYS is 1 and the project is based on the code example 
enetEcho from TI's Starterware (SITARA processor AM3359).
Yes, it is RAW API and the language is C.
The transmission shall start immediately after the timer event, not 
several ms later.
But if I can send from main() - well, that  sounds not that difficult. 
Only acknowledge time might become a problem.
I will check that.
Thank you.
Regards,
Martin H.

Am 03/07/2015 um 14:28 schrieb Sergio R. Caprile:
> Martin H.,
> First of all, what are you using ? Do you have an RTOS or are you
> running on bare metal with NO_SYS=1 ?
> Second, are you using the RAW API or what ?
> Then, how exact needs this "defined time" to be ? You can call a send
> function whenever you want, lwIP (at least the RAW API) is event driven,
> so you can send UDP by just calling the send function when needed. TCP
> is a bit more complicated because it is... well, it is TCP.
> Basically, you can send as much data at once as your buffers allow.
> What is "lwIP context" for you ? Are you programming in C or what ?
> Since there is no udp_sent() callback, I have to guess you are using
> TCP... then, once the connection is established and flow is steady, the
> amount of time until the sent callback is called is what it takes for
> the receiving host to send you an ACK, cause that is how TCP works.