FAQ

On this page you can find answers to many of the questions developer frequently ask about MediaTek LinkIt Connect 7681 developer platform in the following categories:

 

 

 

About the development platform

What is MediaTek LinkIt Connect 7681 development platform?

MediaTek LinkIt™ Connect 7681 development platform is a collection of tools and resources to enable the creation of IoT devices that can be controlled over a Wi-Fi connection.

What is MediaTek MT7681?

The MediaTek MT7681 is the chipset at the heart of MediaTek LinkIt™ 7681 development platform. It is a compact Wi-Fi System-on-Chip (SoC) for IoT devices with embedded TCP/IP stack. By adding the MT7681 to an IoT device it can connect to other smart devices or to cloud applications and services. Connectivity on the MT7681 is achieved using Wi-Fi in either Wi-Fi station or access point (AP) mode.

What can I develop using the MediaTek LinkIt Connect 7681 development platform?

The MediaTek LinkIt Connect 7681 development platform is designed for the creation of Wi-Fi connected IoT devices such as smart switches, smart bulbs, smart locks and alike.

Can I create user apps with the MediaTek LinkIt Connect 7681 development platform?

No. You create custom firmware for the LinkIt connect 7681 to enable IoT devices such as smart appliances, smart bulbs and alike. There isn’t support for adding additional user apps to devices powered by MediaTek MT7681

Why should I be developing for MediaTek LinkIt Connect 7681 development platform?

The market IoT devices is expected to grow rapidly over the next few years, creating new opportunities for software and hardware developers, makers, and manufacturers. By starting to develop with MediaTek LinkIt Connect 7681 today, you’ve the opportunity to be among the first entrepreneurs in this exciting space.

Can you show me any examples of what other makers/manufacturers have created with LinkIt Connect 7681?

You can find commercial products and example projects and based on LinkIt development boards in our Showcase page. 

Where is the datasheet for MT7681?

The datasheet is only available to customers who have signed NDA (Non-Disclosure Agreement) and license agreement with MediaTek.

Hardware features

What I/O ports does LinkIt Connect 7681 provide?

MediaTek LinkIt Connect 7681 provides five GPIO pins and one UART port. In addition PWM is supported in software, for applications such as LED dimming.

Does LinkIt Connect 7681 support Bluetooth?

No, communication with chipset is achieved using Wi-Fi in either Wi-Fi station or access point (AP) mode.

Does LinkIt Connect 7681 support Wi-Fi?

Yes, MediaTek LinkIt Connect 7681 offers Wi-Fi in station mode offering 802.11 b/g/n and access point (AP) mode offering 802.11 b/g.

Does LinkIt Connect 7681 support GNSS?

No, as MediaTek LinkIt Connect 7681 is intended for IoT devices which will generally be static it doesn’t support GNSS (GPS, GLONASS or BeiDou).

Does LinkIt Connect 7681 support AP + Station mode simultaneously?

No, LinkIt Connect 7681 supports only one mode at a time.

Can I connect a 5 volt sensor to LinkIt Connect 7681?

No, because LinkIt Connect  7681 only has 3.3V pin out, therefore you may need to use a level shifter for that purpose.  

Does LinkIt Connect 7681 support FOTA (Firmware Over-the-Air)?

Yes, LinkIt Connect 7681 supports FOTA.  

Does MT7681 support "Wi-Fi Direct" for proprietary usage?

No. LinkIt Connect 7681 does not support Wi-Fi Direct.

What are the default GPIO values of LinkIt Connect 7681?  

For GPIO0, GPIO1 and GPIO2, the default output is HIGH. 

For GPIO3 and GPIO4, the default output is LOW.

Software development

What is the software development environment for LinkIt Connect 7681?

Development for the MediaTek LinkIt Connect 7681 is achieved by creating device firmware with the LinkIt Connect 7681 SDK. The SDK deliver a command line compiler based on the Andes Development Kit.

What computers do the development tools for LinkIt Connect 7681 SDK run on?

The LinkIt Connect 7681 SDK is provided for Microsoft Windows and Ubuntu Linux computers. To run on a Windows PC you will need to have Cygwin installed.

How much memory does LinkIt Connect 7681 have?

The MT7681 has only 64KB memory. So to get better performance, try to use less memory.  

Is it possible to connect external devices to the SPI interface other than flash?

If you are using the LinkIt Connect 7681 board, you won't be able to use the SPI interface for external device, because the SPI interface is hard wired to the on-board flash. If you plan to use the 7681 chip set with your own custom design, you will be able to use the SPI for other purpose other than flash. The SDK for SPI only supports the flash control, including clock set, read, write, erase, and the firmware update/dump. Apparently, the SPI interface cannot be used for other devices.

What can I do to avoid compilation warning while building software?

 

If you are getting compilation warnings like ‘doesn't match the target pattern’,

Makefile:245: target 'cust/vectors.o' doesn't match the target pattern
Makefile:245: target 'cust/startup.o' doesn't match the target pattern 
Makefile:245: target 'cust/ctxsw.o' doesn't match the target pattern 
Makefile:277: target 'cust/vectors.d' doesn't match the target pattern 
Makefile:277: target 'cust/startup.d' doesn't match the target pattern 
Makefile:277: target 'cust/ctxsw.d' doesn't match the target pattern 
clean out/sta/MT7681_sta.elf out/sta/build_sta.log 

The above messages can be ignored. These object files are placed into the source folder, which triggers the above prints from the Makefile. 

  If you don't want to see the above messages, you can modify the makefile by commenting out the line 245 and line 277.

  The final image will be the same.

Line 245 #$(ASM_OBJS) : $(OBJ_PATH)/%.o : $(SRC_PATH)/%.S
Line 277 #$(ASM_DEPENDS) : $(OBJ_PATH)/%.d : $(SRC_PATH)/%.

Hardware development

What is the hardware development environment for MediaTek LinkIt Connect 7681?

Hardware development is achieved with the LinkIt Connect 7681 HDK, which consists of a development board designed and produced by Seeed Studio and a module (which is mounted on the development board) designed and produced by AcSiP.

What is the MediaTek LinkIt Connect 7681 module?

The LinkIt Connect 7681 module is a small board containing the MediaTek MT7681, built in Wi-Fi antenna and external antenna connector (IPEX).

Why is the MediaTek MT7681 supplied on a separate module?

The LinkIt Connect 7681 module is a component that is available separately. This enables you to design your device then purchase the modules to attach to the device’s PCB. This is because MediaTek MT7681 chipset are normally only supplied to MediaTek licensees.

Can I design my own hardware to use LinkIt Connect 7681?

Yes, the schematic and layout design for the development board and module are available for download as part of the LinkIt Connect 7681 Hardware Reference Design. You can also find a datasheets for the chipsets on the LinkIt Connect 7681 Documentation page.

How do I buy MediaTek MT7681 chipsets to make my own hardware? 

MediaTek only sells chipsets directly to licensed customers and partners. To create your own hardware your will purchase LinkIt Connect 7681 modules. The first of these is produced by AcSiP and available through Seeed Bazaar and other distributors. Alternatively you can locate a licensed customers or and work with them to design and manufacture your hardware.

Do I have to create every aspect of my MediaTek LinkIt Connect 7681 device from scratch?

No, MediaTek Labs provides the LinkIt Connect 7681 hardware reference design and, through partner Seeed Studio, the LinkIt Connect 7681 development board and LinkIt Connect 7681 module. The development board provides the core elements of any hardware design enabling you to focus on designing and prototyping the unique aspects of your device.

Purchasing the LinkIt Connect 7681 development board and module

Where do I purchase the LinkIt Connect 7681 development board?

The LinkIt Connect 7681 development board is available from Seeed Bazaar, selected Seeed distributor and TMALL.

Where do I purchase the LinkIt Connect 7681 module?

The LinkIt Connect 7681 module is available from Seeed Bazaar, selected Seeed distributor and TMALL. In addition, AcSiP distributes the module through a number of its partners, a list can be found on the AcSiP website.

Going to market with a LinkIt Connect 7681 based IoT device

How do I get my LinkIt devices to market?

As part of the MediaTek Labs program we’ll help you connect with prototype houses (such as Seeed Studio) as well as ODMs and device manufacturers, so that you can take the necessary steps towards commercializing your IoT devices. 

LinkIt Connect 7681 development troubleshooting

Where can I find more information or help on issues I encounter during development?

If you encounter issues during development, the MediaTek LinkIt Connect 7681 Developer’s Guide includes a Troubleshooting section that describes how to identify and correct issues.

If the guide doesn’t help solve your issue then there are SDK and HDK forums for LinkIt Connect 7681. Here you may be able to find (by searching for relevant words related to your issue) that others have encountered and solve the same issue. If you cannot find a solution then you can use the forum to pose a question to the Labs community.

I don’t seem to be able to compile my firmware for the LinkIt Connect 7681 development board, what might be wrong?

The common reasons for firmware failing to compile are:

  • Incorrectly installed SDK. To resolve check the installation, reinstall if you are unsure and try compiling again.
  • Errors in the code, such as syntax error or references to missing or non-existent components. To resolve check your code for errors and try compiling again.

More details on how to diagnose and resolve compilation issues are provided in the Troubleshooting section of the MediaTek LinkIt Connect 7681 Developer’s Guide

I’m getting errors when uploading firmware, how do I resolve them?

Uploading firmware may not work as expected occasionally. This may be indicated by:

  • the firmware uploader displaying the message Failed to enter 'Recovery Mode' automatically, please press reset key manually.
  • the board not responding as expected after a firmware update.

In these cases, use the reset switch to put the LinkIt Connect 7681 development board into recovery mode. The board should restart and run the firmware as expected. If the board still isn’t behaving as expected, consult question “My board seems to have stopped working, what do I do?”.

Is there debug support for the LinkIt Connect 7681 development board?

A debug log is provided for the LinkIt Connect 7681 development board while it is in Station mode. Full details of the output from this log and how to use it resolve issues is described in the Troubleshooting section of the MediaTek LinkIt Connect 7681 Developer’s Guide.

My board seems to have stopped working, what do I do? 

If your LinkIt Connect 7681 development board becomes unresponsive, you can do the following:

  1. Attempt to reboot the board using either AT#Reboot or the hardware reset button.
  2. Reload the recovery firmware using the uploader.
  3. Reload the recovery firmware using a Flash Programmer.
  4. Contact Seeed Studio support.

Remember also to check the Labs Forums for posts on possible causes and cures.

How can I know LinkIt Connect 7681 is connected to which router?

You can get the MAC address of the connected router.

There is a global variable named pIoTStaCfg, it is in the STA_ADMIN_CONFIG structure. 

The pIoTStaCfg-> Bssid is the MAC address of the connected router.

      pIoTStaCfg-> Bssid; // The MAC of the AP
    
      pIoTStaCfg-> Ssid; // The name of the AP
    
      pIoTStaCfg-> Passphase; // The password of the AP
    
      pIoTStaCfg-> AuthMode; // The authentication mode of the AP
    

How can I modify the baud rate of MT7681? 

Please edit the baud rate macros in these files:

config.h
#define UART_BAUD_RATE 115200
Iot_custom.h
#define DEFAULT_UART_BAUDRATE UART_BAUD_115200

How can I tune into another WiFi Channel?

You can call the API void iot_atcmd_set_channel (uint8 Channel), defined in the iot_api.h file. It is for switching the Wi-Fi channel.

Is there any way to get Chipset serial/ID number of LinkIt Connect 7681?

MT7681 chip has no serial number. However, the MAC address is unique and can be used as the chipset ID.