---
title: "AT commands through Microcontroller"
url: "https://maker.wiznet.io/forum/11485"
markdown_url: "https://maker.wiznet.io/forum/11485/md"
type: "Forum topic"
category: "Wireless"
author: "Dogecoin"
created: "2015-11-27T22:01:40+09:00"
last_activity: "2017-05-04T08:37:39+09:00"
language: "en"
views: 765
replies: 1
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# AT commands through Microcontroller

## Question

Asked by Dogecoin on 2015-11-27 in Wireless.

Dear WiFi enthosiasts,

I am trying to establish a serial port connection between an mbed LPC11U24 board and the WizFi220 Evaluation Board. I have connected the tx and rx pins of the microcontroller to the rx and tx pins of the WizFi, and I attempt to send the basic ‘AT’ command at a baudrate of 115200. The writing seems to be accepted by the microcontroller, but when I use the mbed’s native readable() function (which checks whether there is something to read at the UART).
The function doesn’t show the WizFi as readable, no matter what I do.

Are there any basic settings or oft-made mistakes that I possibly have done? Is there any workable non-Arduino microcontroller code using the UART (or another means of communication) findable on the web?

Best regards,

An electronics newbie

## Replies

### Reply 1 by wizdaniel, 2015-12-03

Hi.

1. Please check the led blink when power is up.

2. Re-write the firmware because uart firmware and spi firmware exists Independently.

3. please check correct connection, default uart is UART0(J9)

4. check the 2 switchs, move to [RUN], move to [CMD] on the Evaluation board.

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Source: https://maker.wiznet.io/forum/11485