topic Re: send and receive data via TCP connection using Lwip in LPC Microcontrollers

send and receive data via TCP connection using Lwip

gonzalo_sipel — Tue, 14 May 2019 19:07:23 GMT

I'm new on using LWIP and I'm taking my first steps into it. I'm using a self-designed board based on LPC1788 microcontroller and I've been able to run both the lwip_tcpecho and the lwip_web projects successfully so far (I'm using raw API without RTOS).
Now, I would like to send and receive data via a TCP connection but I'm a bit lost where and how to start doing this. I was thinking, as my first step, that I might modify the lwip_tcpecho example in order to show via the DEBUGOUT UART the received data and to send via the TCP connection the data read from DEBUGIN. (Something like a simple RS-232 to TCP converter).

Has anyone done something like this? If so, could you share some piece of code that helps me?

Am I taking the right path? I'm not using RTOS since in the future I have to add this to my existing code which doesn't run RTOS.

what function should I call to get the data received into my app buffer and what function should I call to send data from my app buffer?

Regards!

Re: send and receive data via TCP connection using Lwip

jeremyzhou — Wed, 15 May 2019 07:41:43 GMT

Hi Gonzalo Sanchez,

Thank you for your interest in NXP Semiconductor products and for the opportunity to serve you.
Whether you use the Lwip demos which comes from the LPCOpen library as the template demo, if yes, it's a good start.
Meanwhile, implement a simple RS-232 to TCP converter is the right choice to move further, so please give a try, and ask the question if you encounter some troubles

Have a great day,
TIC

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Re: send and receive data via TCP connection using Lwip

gonzalo_sipel — Wed, 15 May 2019 11:28:23 GMT

Hi Jeremy, thank you for let me know that I'm on the right path.

What I do not totally understand is how my application can interact with LWIP to receive and send information. I mean, what function should I call to get the data received into my app buffer and what function should I call to send data from my app buffer?

I've updated my post with this question too.

Regards,

Gonzalo.

Re: send and receive data via TCP connection using Lwip

jeremyzhou — Thu, 16 May 2019 07:40:53 GMT

Hi Gonzalo Sanchez,

Thanks for your reply.
To provide the fastest possible support, I'd like to you refer to the LwIP Application Developers Manual.

Have a great day,
TIC

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