---
title: "W5500 How to put data in Socket TX buffer"
url: "https://maker.wiznet.io/forum/13468"
markdown_url: "https://maker.wiznet.io/forum/13468/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "david20002062"
created: "2019-09-03T12:42:33+09:00"
last_activity: "2019-09-05T04:16:17+09:00"
language: "en"
views: 1183
replies: 2
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# W5500 How to put data in Socket TX buffer

## Question

Asked by david20002062 on 2019-09-03 in Ethernet Chips.

Hi!

I’ve been working on some bare-metal STM32 stuff and currently I’d need to use the W5500 Ethernet chip… I’ve written the SPI communication, however I cannot put data into the Socket TX Buffer… maybe my code is wrong… but the W5500 doesn’t seem to set the write pointer when I send the new one after I sent the data to the tx buffer (the address for which is read from the tx write pointer)

I don’t have much experience with the W5500 chip, could somebody help me?

## Replies

### Reply 1 by becky, 2019-09-04

Are you success at reading and writing other registers than the tx buffer?
I don’t know what to do for you. If you show your code I can confirm it.
Do you not use iolibrary?
In the case of tcp, data is sent through send() in socket.c.

![](https://github.githubassets.com/favicons/favicon.svg) [GitHub](https://github.com/Wiznet/ioLibrary_Driver)

![](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/1/17f66f2e9c27f9749e7af3ad7efe15d9492bea3b.png)

### [GitHub - Wiznet/ioLibrary_Driver: ioLibrary_Driver can be used for the...](https://github.com/Wiznet/ioLibrary_Driver)

ioLibrary_Driver can be used for the application design of WIZnet TCP/IP chips as W5500, W5300, W5200, W5100 W5100S. - GitHub - Wiznet/ioLibrary_Driver: ioLibrary_Driver can be used for the applica...

### Reply 2 by becky, 2019-09-05

In addition, I recommend to refer [w5500.com](http://w5500.com) .
There are w5500 code for stm32 board, but it is a Chinese site.
You should refer to it using the translator.

The following is an W5500 TCP Server Example on Keil Project.
<http://w5500.com/code//W5500EVB/zip/TCPS.zip>

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Source: https://maker.wiznet.io/forum/13468