Breakout for LinkIt Smart 7688 v2.0

Breakout for LinkIt Smart 7688 v2.0 is a Grove port integrated expansion board for LinkItTM Smart 7688 development board. This breakout board will help beginners to get started fast because it can save a lot of work and make prototyping easier through simplified wiring. It comes with USB, Ethernet, and 3.5mm Audio ports and supports serial buses like I2C, UART.

Version Tracker

Product reversion Release date Support status Notes
Version 1.0 November 2015 Supported None
Version 2.0 April 2016 Supported Refer to New Features

New features:

  • Support recording functionality.
  • For 3.5 mm phone connector (audio jack), it supports the protocol OMTP and CTIA. You can use either protocol by toggling a switch. About how to switch protocol, we will please sroll down the page to read How to switch phone connector protocol between OMTP and CTIA

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  • Grove interface makes wiring easier and allows expansions with Grove modules.
  • USB host
  • Audio Output
  • Ethernet port
  • Cost-effective
  • Support recording functionality
  • Switch between OMTP and CTIA

Application ideas

  • IoT/Gateway Device.
  • Robotics
  • Smart multimedia devices
  • Teaching and learning


Input voltage Operating voltage
5.0V(With USB Power port) 3.3V


Debug pins, Ethernet pins and USB type-A host pins connect with MT7688, other pins connect with ATmega32U4.

Hardware Overview

Hardware Qty Hardware Qty Hardware Qty
Debug port 1 Headset port 1 Aux Pins 2
Ethernet port 1 Pins to switch protocol 6 Grove Connector 3
USB type-A 1 Stereo Speaker driver interface 1 Headset port 1

About Grove interface

If you ever used Seeed's Grove products, you will fell in love with this kind of modules. With this kind of ports, you can say goodbye to jumper wire and soldering work, and you can make more powerful applications with those functional modules.

How to switch phone connector protocol between OMTP and CTIA

If you compare V1.0 and V2.0, you can notice that there are six pins and two jumper caps on bottom-right corner. These pins are used to switch phone connector protocol. As you set tiny jumper(both) to left-four pin, protocol OMTP is used. As you set tiny jumper(both) to right-four pin (as preceded figure shows), protocol CTIA is used. As following figures show: Breakout for LinkIt Smart 7688 v2.0 CTIA OMTP Switch Manner.JPG Note that to use the recording functionality, you need to update on-board firmware to Breakout for LinkIt Smart 7688 firmware(above version v0.9.2).


  • Because the Write/Read speed of on-board flash memory is limited, We recommend you to use external storage device.

Get started

In this tutorial, you are going to make a simple MP3 player with Breakout for LinkIt Smart 7688 V2.0.

Material required

Except Breakout for Linkit Smart 7688 V2.0, here are other materials that is needed for the application. Before you start, please make sure you have every thing on hand, or you can visit Seeed Bazzar to get them.

LinkIt Smart 7688 × 1 USB cable (type A to micro type-B) × 2 UARTBee × 1 Jumper wires × 3
Get One Now Get One Now Get One Now Get One Now

For below 2, I think you surely have them. - Stereo Speaker(with 3.5 mm audio cable) × 1 - USB flash disk (with audio file of MP3 format inside) × 1

Step1: Refer here to connect your LinkIt Smart 7688 to Internet.


You can plug jumper wires to MT7688 UART2 port instead soldering them to Pin 8, Pin 9 and Pin GND.


In rare cases, you might not connect to Internet successfully, reboot the embedded OS.

Step2: Open a console with USB to Serial adapter.

Step3: Connect all parts like follows:


This is a figure of Breakout for LinkIt Smart 7688(v1.0).

Step4: Enter folder of USB by type cd /Media/USB-A1 in console.

Step5: Play music with utility Madplay(installed on OpenWRT) by typing madplay filename.mp3 into console.

Step6: Now you will hear the music.

Schematic Online Viewer



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