Tag Archives: Linkit

Configuration, Software

LEDE on Linkit 7688 Duo – Timecheck example

2017-08-13 admin

After the Python ad Firmata example

Firmata and Python

in this example we use the following programming model

We enable the board to work like Arduino Yun

Linkit 7688 Duo Arduino Yun

As specified in the Mediatek link, you must enable the bridge on the board; from a terminal in Lede run

uci set yunbridge.config.disabled='0'  
uci commit  
reboot

uci set yunbridge.config.disabled='0'

uci commit

reboot

At the reboot go to the Arduino Ide and choose File->Examples->Bridge->TimeCheck

We used the 1.6.5 Arduino Ide; we had issues whith the 1.8 version to build the sketch.

From the Arduino Ide, after the code upload, go to Tool->Serial Monitor to open the serial monitor

The serial monitor window shows the current time.

After that, to run the other examples , disable the bridge setting with the commands

uci set yunbridge.config.disabled='1'  
uci commit  
reboot

uci set yunbridge.config.disabled='1'

uci commit

reboot

Installation, Software

Installation and configuration of Lede image on Linkit 7688 Duo

2017-07-19 admin

After you have attached to the board the support devices, as specified in the previous article

Linkit 7688 Duo Connections

and built the image

Lede Image for Linkit 7688 Duo

we upload the image to the device.

Following the documentation availble at the link

Update the firmware with a USB drive

to update the firmware copy the lede-ramips-mt7688-LinkIt7688-squashfs-sysupgrade.bin file to the root directory of a FAT32 USB drive and rename it as lks7688.img.

Attach, now, the USB drive to the HOST port of the board with an OTG cable and follow the steps

Press and hold the on-board WiFi button.
Press the MPU reset button once, while holding the WiFi button.
Keep holding the WiFi button for about 5 seconds. Do not release until the orange LED for WiFi is off. DO NOT press the WiFi button longer than 20s or it will upgrade the bootloader.
The device will automatically reboot after firmware update is complete.

You can control the operation via the USB TTL serial connected to the PC and activated on the enabled Com port with the following settings

Port: Enabled COM
Speed: 57600
Data Bits: 8
Stop Bits: 1
Parity: None
Flow Control: XON/XOFF

Use, for example, putty to connect, press Enter if the screen is not active, and to check the steps the system is runnig when upgrading

When the orange LED starts blinking at a lower frequency the card is ready to be used

On the Lede system, the wireless card is disabled by default, while Lan is operational, but only accessible via a Breakout board

Linkit Breakout

To enable the wireless card connect with putty (screen on Linux) to the previously connected USB TTL serial and go to the /etc/config folder; edit the network file and add at the end the following section

config interface 'wlan'
        option proto 'dhcp'

1 2	config interface 'wlan' option proto 'dhcp'

Save and run

uci commit network

1	uci commit network

Edit the wireless file and add at the end the section

config wifi-iface 'sta_radio0'
        option device 'radio0'
        option mode 'sta'
        option ssid 'Access Point'
        option key 'password'
        option encryption 'psk2'
        option network 'wlan'

config wifi-iface 'sta_radio0'

option device 'radio0'

option mode 'sta'

option ssid 'Access Point'

option key 'password'

option encryption 'psk2'

option network 'wlan'

where Access Point and password indicate the Access Point name and password; the wireless security setting is wpa2.

Save and run

uci set wireless.radio0.disabled=0; uci commit wireless;

1	uci set wireless.radio0.disabled=0; uci commit wireless;

Enable the wireless, running

wifi

wifi

Access the Lede interface with the address assigned by the Access Point

Set the password and access to the Lede management.

In this firmware, the leds on the board are not synchronized with wireless operations, unlike from OpenWrt firmware with the Mediatek proprietary interface and drivers.

In the next article, we will give some examples of interfacing with the arduino IDE, based on the tutorial on the Mediatek site using this custom Lede image

LEDE on Linkit 7688 Duo – MPU-MCU Uart communication

Installation, Software

Installation and configuration of the Openwrt Image on Linkit 7688 and 7688 Duo

2017-07-15 admin

After you have attached to the board the support devices, as specified in the previous article

Linkit 7688 Duo Connections

and built the image

OpenWrt building for Linkit 7688 and 7688 Duo

we upload the image to the device.

Following the documentation availble at the link

Update the firmware with a USB drive

to update the firmware copy the openwrt-ramips-mt7688-LinkIt7688-squashfs-sysupgrade.bin file to the root directory of a FAT32 USB drive and rename it as lks7688.img.

Attach, now, the USB drive to the HOST port of the board with an OTG cable and follow the steps

Press and hold the on-board WiFi button.
Press the MPU reset button once, while holding the WiFi button
Keep holding the WiFi button for about 5 seconds. Do not release until the orange LED for WiFi is off. DO NOT press the WiFi button longer than 20s or it will upgrade the bootloader.
The device will automatically reboot after firmware update is complete.

You can control the operation via the USB TTL serial connected to the PC and activated on the enabled Com port with the following settings

Port: Enabled COM
Speed: 57600
Data Bits: 8
Stop Bits: 1
Parity: None
Flow Control: XON/XOFF

Use, for example, putty to connect, press Enter if the screen is not active, and check the steps the system is runnig when upgrading

When the orange LED starts blinking at a lower frequency the card is ready to be used.

Search for visible access points from your PC and you should find an access point named LinkIT_Smart_7688_xxxxxx, where xxxxxx identifies the specific device.

Connect to this Access Point and access via browser at 192.168.100.1 or at mylinkit.local if you have satisfied the prerequisites

Getting started

Enter a password and access the next step

Select OpenWrt for Advanced Configuration

Set the password on OpenWrt

entering it twice

At this point, the system is configured as an Access Point. In our case, we wanted to set the Link 7688 Duo as a client of an Access Point with WPA2 security. To get this setting, if you have a visible network, go to the Network section of the main web console interface

set the values for the Access Point and restart the system

If the Access Point is hidden, you should set the parameters directly in the configuration files in /etc /config.

Connect with putty to the previously connected USB TTL serial and run the commands for Access Points with wpa2 security

uci set wireless.sta.ssid=ACCESS POINT
uci set wireless.sta.key=password access point
uci set wireless.sta.encryption=psk2

uci set wireless.sta.ssid=ACCESS POINT

uci set wireless.sta.key=password access point

uci set wireless.sta.encryption=psk2

Save the settings

uci commit

1	uci commit

and activate the new configuration

wifi_mode sta

1	wifi_mode sta

Check the /etc/config/wireless file; you should see the addition of a new section, config wifi-iface ‘ap’, to connect the board to the access point

root@mylinkit:/etc/config# cat wireless

config wifi-device 'radio0'
        option type 'ralink'
        option variant 'mt7628'
        option country 'TW'
        option hwmode '11g'
        option htmode 'HT40'
        option channel 'auto'
        option disabled '0'
        option linkit_mode 'sta'

config wifi-iface 'ap'
        option device 'radio0'
        option mode 'ap'
        option network 'lan'
        option ifname 'ra0'
        option encryption 'none'
        option ssid 'LinkIt_Smart_7688_1C4775'
        option seq '1'

config wifi-iface 'sta'
        option device 'radio0'
        option mode 'sta'
        option network 'wan'
        option ifname 'apcli0'
        option led 'mediatek:orange:wifi'
        option ssid 'AccessPoint'
        option key 'password'
        option encryption 'psk2'

root@mylinkit:/etc/config#

root@mylinkit:/etc/config# cat wireless

config wifi-device 'radio0'

option type 'ralink'

option variant 'mt7628'

option country 'TW'

option hwmode '11g'

option htmode 'HT40'

option channel 'auto'

option disabled '0'

option linkit_mode 'sta'

config wifi-iface 'ap'

option device 'radio0'

option mode 'ap'

option network 'lan'

option ifname 'ra0'

option encryption 'none'

option ssid 'LinkIt_Smart_7688_1C4775'

option seq '1'

config wifi-iface 'sta'

option device 'radio0'

option mode 'sta'

option network 'wan'

option ifname 'apcli0'

option led 'mediatek:orange:wifi'

option ssid 'AccessPoint'

option key 'password'

option encryption 'psk2'

root@mylinkit:/etc/config#

Now the card acts as a client and you can access it using the address released by the Access Point or by name as indicated by the documentation

Getting started

In the next article, we’ll install and configure the custom Lede firmware

Installation and configuration of Lede image on Linkit 7688 Duo

Compilation, Software

LEDE building for Linkit 7688 Duo

2017-07-09 admin

After OpenWrt image building using the Mediatek SDK

OpenWrt building for Linkit 7688 and 7688 Duo

this article describes how to generate a LEDE image for the Linkit 7688 Duo.

The steps on how to compile LEDE are available at the link

LEDE Building

Clone the code from the github in a shell command window, always from the Linkit folder

cd
cd Linkit

1 2	cd cd Linkit

run

git clone https://git.lede-project.org/source.git Lede

1	git clone https://git.lede-project.org/source.git Lede

Create the src folder under Linkit and extract the compressed file

Feed for Linkit

This feed was created from Mediatek one, eliminating the binary drivers dependency.

Copy the file to the src folder and uncompress it

sviluppo@debian:~/Linkit/src$ ls
linkit.tar.gz
sviluppo@debian:~/Linkit/src$ tar -zxvf linkit.tar.gz

sviluppo@debian:~/Linkit/src$ ls

linkit.tar.gz

sviluppo@debian:~/Linkit/src$ tar -zxvf linkit.tar.gz

sviluppo@debian:~/Linkit/src$ ls
linkit  linkit.tar.gz
sviluppo@debian:~/Linkit/src$

sviluppo@debian:~/Linkit/src$ ls

linkit linkit.tar.gz

sviluppo@debian:~/Linkit/src$

Go to the Lede folder and copy the feeds.conf.default file as feeds.conf

cd 
cd Linkit/Lede
cp feeds.conf.default feeds.conf

cd Linkit/Lede

cp feeds.conf.default feeds.conf

Run

echo src-cpy  linkit ~/Linkit/src/linkit >> feeds.conf

1	echo src-cpy linkit ~/Linkit/src/linkit >> feeds.conf

Update the feeds for the packages

./scripts/feeds update

1	./scripts/feeds update

Install the packages

./scripts/feeds install -a

1	./scripts/feeds install -a

Configure the kernel executing

make menuconfig

1	make menuconfig

Use the following settings

Target System: Mediatek Ralink MIPS
Subtarget: MT7688 based boards
Target Profile: Mediatek LinkIt Smart 7688

In the Base system section enable mtk-linkit

Save and exit.

Run the building

make V=s -j x

1	make V=s -j x

where x is the number of cores to use in the building.

At the end of the process the generated image is available in the bin/targets/ramips/mt7688/ folder as lede-ramips-mt7688-LinkIt7688-squashfs-sysupgrade.bin.

The built firmware is available here

Lede Image for Linkit 7688 Duo

WARNING: The image installation on the device is at your own risk. We accept no responsibility if the installation leads to malfunction or block of the device.

If you upgrade the board using an usb key, you need to rename the lede-ramips-mt7688-LinkIt7688-squashfs-sysupgrade.bin file in lks7688.img.

This firmware may have malfunctions as it is not thoroughly tested and based on drivers under development.

In the next articles we’ll upload the images to the board and configure them

Installation and configuration of the Openwrt Image on Linkit 7688 and 7688 Duo

Compilation, Software

OpenWrt building for Linkit 7688 and 7688 Duo

2017-07-09 admin

After describing the general specifications of the two boards in the previous article

Linkit 7688 and 7688 Duo Development Boards

now we build the OpenWrt image from the sources. The following link describes the steps

Building the firmware from the source code

First we have to create the folder Linkit under /home/sviluppo in a shell command window in our Debian image, already used to build OpenWrt in another article

Building OpenWrt Image

cd
mkdir Linkit
cd Linkit

mkdir Linkit

cd Linkit

Install the prerequisites

sudo apt-get install git-core 
sudo apt-get install build-essential 
sudo apt-get install libssl-dev 
sudo apt-get install libncurses5-dev 
sudo apt-get install unzip 
sudo apt-get install gawk
sudo apt-get install subversion 
sudo apt-get install mercurial
sudo apt-get install libxml-parser-perl
sudo apt-get install g++

sudo apt-get install git-core

sudo apt-get install build-essential

sudo apt-get install libssl-dev

sudo apt-get install libncurses5-dev

sudo apt-get install unzip

sudo apt-get install gawk

sudo apt-get install subversion

sudo apt-get install mercurial

sudo apt-get install libxml-parser-perl

sudo apt-get install g++

Clone the OpenWrt repository

git clone git://git.openwrt.org/15.05/openwrt.git

1	git clone git://git.openwrt.org/15.05/openwrt.git

In the shell command window go to the openwrt folder and copy feeds.conf.default file as feeds.conf

cd openwrt
cp feeds.conf.default feeds.conf

1 2	cd openwrt cp feeds.conf.default feeds.conf

Add the Mediatek feed for the boards

echo src-git linkit https://github.com/MediaTek-Labs/linkit-smart-7688-feed.git >> feeds.conf

1	echo src-git linkit https://github.com/MediaTek-Labs/linkit-smart-7688-feed.git >> feeds.conf

Update the feeds for the packages

./scripts/feeds update

1	./scripts/feeds update

Install the packages

./scripts/feeds install -a

1	./scripts/feeds install -a

Configure the kernel executing

make menuconfig

1	make menuconfig

Use the following settings

Target System: Ralink RT288x/RT3xxx
Subtarget: MT7688 based boards
Target Profile: LinkIt7688

Save and exit.

Run the building

make V=99

make V=99

At a certain point, the building generates an error for the wireless card libraries. Mediatek has not released the wireless card sources, but an sdk with compiled binaries for a kernel version different from the one we are using in the building; the error reported is

cp -fpR ./wifi_binary/mt_wifi.ko_3.18.45 /home/sviluppo/Linkit/openwrt/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7688/mtk-sdk-wifi-2015-06-01/ipkg-ramips_24kec/mtk-sdk-wifi/lib/modules/3.18.45/mt_wifi.ko
cp: cannot stat './wifi_binary/mt_wifi.ko_3.18.45': No such file or directory
Makefile:93: recipe for target '/home/sviluppo/Linkit/openwrt/bin/ramips/packages/linkit/mtk-sdk-wifi_2015-06-01-ade8b1b299cbd5748db1acf80dd3e9f567938371_ramips_24kec.ipk' failed
make[3]: *** [/home/sviluppo/Linkit/openwrt/bin/ramips/packages/linkit/mtk-sdk-wifi_2015-06-01-ade8b1b299cbd5748db1acf80dd3e9f567938371_ramips_24kec.ipk] Error 1
make[3]: Leaving directory '/home/sviluppo/Linkit/openwrt/feeds/linkit/mtk-sdk-wifi'
package/Makefile:191: recipe for target 'package/feeds/linkit/mtk-sdk-wifi/compile' failed
make[2]: *** [package/feeds/linkit/mtk-sdk-wifi/compile] Error 2
make[2]: Leaving directory '/home/sviluppo/Linkit/openwrt'
package/Makefile:188: recipe for target '/home/sviluppo/Linkit/openwrt/staging_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/stamp/.package_compile' failed
make[1]: *** [/home/sviluppo/Linkit/openwrt/staging_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/stamp/.package_compile] Error 2
make[1]: Leaving directory '/home/sviluppo/Linkit/openwrt'
/home/sviluppo/Linkit/openwrt/include/toplevel.mk:181: recipe for target 'world' failed
make: *** [world] Error 2
sviluppo@debian:~/Linkit/openwrt$

cp -fpR ./wifi_binary/mt_wifi.ko_3.18.45 /home/sviluppo/Linkit/openwrt/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7688/mtk-sdk-wifi-2015-06-01/ipkg-ramips_24kec/mtk-sdk-wifi/lib/modules/3.18.45/mt_wifi.ko

cp: cannot stat './wifi_binary/mt_wifi.ko_3.18.45': No such file or directory

Makefile:93: recipe for target '/home/sviluppo/Linkit/openwrt/bin/ramips/packages/linkit/mtk-sdk-wifi_2015-06-01-ade8b1b299cbd5748db1acf80dd3e9f567938371_ramips_24kec.ipk' failed

make[3]: *** [/home/sviluppo/Linkit/openwrt/bin/ramips/packages/linkit/mtk-sdk-wifi_2015-06-01-ade8b1b299cbd5748db1acf80dd3e9f567938371_ramips_24kec.ipk] Error 1

make[3]: Leaving directory '/home/sviluppo/Linkit/openwrt/feeds/linkit/mtk-sdk-wifi'

package/Makefile:191: recipe for target 'package/feeds/linkit/mtk-sdk-wifi/compile' failed

make[2]: *** [package/feeds/linkit/mtk-sdk-wifi/compile] Error 2

make[2]: Leaving directory '/home/sviluppo/Linkit/openwrt'

package/Makefile:188: recipe for target '/home/sviluppo/Linkit/openwrt/staging_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/stamp/.package_compile' failed

make[1]: *** [/home/sviluppo/Linkit/openwrt/staging_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/stamp/.package_compile] Error 2

make[1]: Leaving directory '/home/sviluppo/Linkit/openwrt'

/home/sviluppo/Linkit/openwrt/include/toplevel.mk:181: recipe for target 'world' failed

make: *** [world] Error 2

sviluppo@debian:~/Linkit/openwrt$

One way to fix the problem is the following.

Go to the /home/sviluppo/Linkit/openwrt/feeds/linkit/mtk-sdk-wifi/wifi_binary/ folder and copy the files for our kernel version

cp mt_wifi.ko_3.18.44 mt_wifi.ko_3.18.45
cp mt_wifi.ko_3.18.44_all  mt_wifi.ko_3.18.45_all

1 2	cp mt_wifi.ko_3.18.44 mt_wifi.ko_3.18.45 cp mt_wifi.ko_3.18.44_all mt_wifi.ko_3.18.45_all

Rerun the building. At the end of the process the generated file is available in the bin/ramips folder

The built firmware is available here

OpenWrt Linkit 7688 and 7688 Duo Image

WARNING: The image installation on the device is at your own risk. We accept no responsibility if the installation leads to malfunction or block of the device.

If you upgrade the board using an usb flah drive, you need to rename the openwrt-ramips-mt7688-LinkIt7688-squashfs-sysupgrade.bin file in lks7688.img.

The image kernel for this building is 3.18_45; If you want to use a recent kernel, you must use the opensource drivers available for the board; in the case of the Linkit 7688 Duo card, in our possession, we can rebuild the image using the Realtek rt76 drivers for the wireless network adapter and add the additional components for the Atmel MCU using LEDE, an OpenWrt fork

LEDE Project

In the next article you will build a LEDE image for the Linkit 7688 Duo board. For the Linkit 7688 board at this time, the mraa libraries, used to interface the periphals, are not yet compatible with the latest version of LEDE and the functionality of the image is limited. There may be also bugs in the wireless card opensource drivers, which hopefully are solved in the refinement of these drivers.

LEDE building for Linkit 7688 Duo

Hardware

Linkit 7688 Duo Connections

2017-07-09 admin

After the board specifications summary

Linkit 7688 and 7688 Duo Development Boards

this article describes how to connect to the board the following components that will be used later:

Micro USB OTG to the Host port
USB TTL Serial Device
5 V power supply to the port USB Power

The following diagram shows the connections to the board

The table below shows the connections between the USB TTL Serial device and the board

USB TTL Pin	Linkit Pin
RX	UART_TXD2
TX	UART_RXD2
GND	GND

In the netxt article we will show how to build the firmware for the Linkit 7688 and Linkit 7688 Duo

OpenWrt building for Linkit 7688 and 7688 Duo

Hardware

Linkit 7688 and 7688 Duo Development Boards

2017-07-09 admin

This article briefly describes the Mediatek Linkit 7688 and 7688 Duo development boards. Below the links for the two boards

Linkit 7688

Linkit 7688 Duo

The specifications of the two boards are the following

Linkit 7688

Model	Linkit Smart 7688
MPU	MT7688AN, MIPS24KEc, 580MHz
RAM	128 Mb DDR2
Flash memory	32 Mb
GPIO	22 (MT7688AN) 3,3 V
PWM	4 (MT7688AN) 3,3 V
Expernal Interrupts	22 (MT7688AN)
SPI	1 (MT7688AN)
UART Lite	3 (MT7688AN)
Power	Micro USB 5V DC or PIN 3,3 V
USB HOST	Micro USB
Ethernet	By extension
Wifi	1T1R 802.11 b/g/n (2.4G)
User storare	Micro SDSDXC sdcard
Dimensions	55.7 x 26 mm
Weight	39 grams

Linkit 7688 Duo

Model	Linkit Smart 7688 Duo
MPU	MT7688AN, MIPS24KEc, 580MHz
MCU	Atmel AVR 8MHz
RAM	128 Mb DDR2
Flash memory	32 Mb
GPIO	3 (MT7688AN) 3,3 V 24 (ATmega32U4)
PWM	8 (ATmega32U4) 3,3 V
External Interrupts	8 (ATmega32U4)
SPI	1 (ATmega32U4)
UART Lite	1 (ATmega32U4) 1 (MT7688AN)
Power	Micro USB 5V DC or PIN 3,3 V
USB HOST	Micro USB
Ethernet	By extension
Wifi	1T1R 802.11 b/g/n (2.4G)
User storage	Micro SDSDXC sdcard
Dimensions	55.7 x 26 mm
Weight	39 grams

The two boards share the same Microprocessor (MPU MT7688AN), but in the case of the Linkit 7688 Duo this MPU is supported by the Atmel Microcontroller (MCU ATmega32U4) for device management.

The interfacing schemes are shown with peripherals in the two cases below

The operating system used for both bords is OpenWrt, but the peripherals management is different. While in the case of Linkit 7688 we only rely on MPUs and specific libraries to manage the interfacing with peripherals, for the Linkit 7688 Duo the ATmega32U4 microcontroller manages the peripherals. The programming of the ATmega32U4 is executed with the Arduino IDE by adding the Linkit 7688 Duo board support into the tool as specified at the following link

Arduino Ide support for Linkit 7688 Duo

At the followning link there is the Mediatek documentation for the two boards

Linkit 7688 and 7688 Duo Resources

The following pages show how the two boards can interact with the various peripherals

Linkit 7688 peripherals

Linkit 7688 Duo peripherals

At the Mediatek site, there are also examples to follow step by step to test the various features of the development boards.

The next article shows how to connect the USB OTG cable , to use with a USB drive, an USB TTL serial cable, to monitor the device, to the board

Linkit 7688 Duo Connections

Micro Devices

Tag Archives: Linkit

LEDE on Linkit 7688 Duo – Timecheck example

Installation and configuration of Lede image on Linkit 7688 Duo

Installation and configuration of the Openwrt Image on Linkit 7688 and 7688 Duo

LEDE building for Linkit 7688 Duo

OpenWrt building for Linkit 7688 and 7688 Duo

Linkit 7688 Duo Connections

Linkit 7688 and 7688 Duo Development Boards

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