VAR-SOM-MX6 Android Unit Testing KK 443 200

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Unit Testing & Engineering Notes


The default Android sound recorder application use a a very low sampling rate producing a poor sound.

Plug a Disk-On-Key FAT32 formated into the USB host port.

Plug an audio source (like a PC line out or smartphone line out) into the line in connector.

Plug speakers (like PC speakers) into the line out connector.

root@android:/ # tinycap /mnt/media_rw/usbdisk/test0.wav 

Hit CTRL-C after couple of seconds or more.

root@android:/ # tinyplay /mnt/media_rw/usbdisk/test0.wav  

USB OTG as a device

Test the OTG as a device using Android ADB tool.
On target:
Under devloper option enable ADB debugguing

On Host:

$ sudo out/host/linux-x86/bin/adb kill-server
$ sudo out/host/linux-x86/bin/adb start-server
$ sudo out/host/linux-x86/bin/adb devices
$ sudo out/host/linux-x86/bin/adb shell

USB OTG as a host

Use an external HUB. Plug into it a Disk-On-Key, mouse and keyboard.

Make sure with the Android GUI that they are functional. Test USB Stick with:

$ dd if=/dev/zero of=/dev/sdb bs=128K count=10000

In VAR-DVK-SOLO and VAR-DVK-DUAL the USB OTG port is configured as OTG.
In VAR-DVK-MX6 the USB OTG port is configured as device. To configure it as host a change in the device tree is required.


Plug a mouse into all 3 ports and make sure it is working.

Use an external HUB. Plug into it a Disk-On-Key, mouse and keyboard.
Plug it into all 3 ports and make sure all 3 devices are functioning.


Install tools on host

$ sudo add-apt-repository ppa:nilarimogard/webupd8
$ sudo apt-get update
$ sudo apt-get install android-tools-fastboot
$ sudo apt-get install android-tools-adb android-tools-fastboot

Flash target eMMC

Make sure you built Android for emmc

In case you already have partitions on the eMMC you can skip the next step.

$ sudo `which fastboot` flash mbr  emmc_mbr.img

The mbr need to be collected once of an eMMC formatted target. You can install the eMMC for the fisrt time by using our nand-recovery utility.

$ dd if=/dev/mmcblk1 of=emmc_mbr.img bs=512 count=1

Boot the target press spacebar to stop at u-boot and run "fastboot". From KitKat build folder

$ sudo `which fastboot` flash boot out/target/product/var_mx6/boot-som-solo-vsc.img
$ sudo `which fastboot` flash recovery out/target/product/var_mx6/recovery-som-solo-vsc.img
$ sudo `which fastboot` flash system out/target/product/var_mx6/system.img
$ sudo `which fastboot` reboot

You need to pick and choose the right image for your development system. Follow the link for more information. Available Images


Boot the system and press spacebar to get into u-boot. Change enviroment setting with the folowing command add

$ setenv bootargs console=ttymxc0,115200 init=/init video=mxcfb0:dev=hdmi,1920x1080M@60,if=RGB24,bpp=32 video=mxcfb1:off video=mxcfb2:off video=mxcfb3:off vmalloc=400M androidboot.console=ttymxc0 consoleblank=0 androidboot.hardware=freescale cma=384M androidboot.serialno=0f1c99d4df647283

Plug an HDMI TV or monitor to the HDMI port and boot the system by typing boot into u-boot.

You should see the Android on a full 1080p device.

Audio over HDMI

Download and install SoundAbout pm install /mnt/media_rw/usbdisk/apk/ Use the GUI to set the service as foreground and select the audio over HDMI.

External LVDS display

The current Linux kernel is device tree based kernel. In order to switch LVDS display setting a change in the kernel device tree is required.


Just plug a cable into the system



VAR-SOM-MX6 V2.X & V1.x(Wilink6/WiLink8): First time need to set mac address to be used automatically

$ mount -o remount,rw /system 
$ calibrator set nvs_mac /system/etc/firmware/ti-connectivity/wl1271-nvs.bin 00:00:00:00:00:00

VAR-SOM-MX6 V2.X (WiLink8): First time need to select your correct device

  • Select your WL183x p/n:
  • Make sure the wifi is off
$ mount -o remount,rw /system 
$ cd /etc/wifi/wlconf
$ . ./ wl1831
select one out of : WL1831, WL1833, WL1835, WL1837.
As a result some additional information may be required like 1/2 antenna connected
By default the above steps are not required.


Use the Android GUI to enable and connect to a WIFI AP.


Use the Android GUI to enable.

Test with file transfer to host PC, Bluetooth mouse and Bluetooth keyboard.


Use the Android GUI to activate and test the camera. You can take a picture and send it over Bluetooth to a PC host.


First time boot of Android must be with camera module installed. If you booted without the camera module installed Android will mark the system as "no camera". In such a case you need to re flash the Android and first time boot it with camera installed.


$ busybox fdisk -ul /dev/block/sda

In the above commands you will see SCSI status and device partition table.

If the device is FAT32 formated Android will auto mount it.

RTC (Real Time Clock)

Disable the auto clock sync from the Android GUI.

busybox date 2013.12.01-10:50
busybox hwclock --systohc

Also can set clock via GUI and check it later.

In any method power down the board and wait 5 minutes. After that power up the board and check the the clock is correct.


We added support for canbus in the kernel and the support library layer.

Connect 2 boards. Each board JP26 connect to the other with the right cable. Set the 2 boards:

$ ip link set can0 up type can bitrate 1000000
$ busybox ifconfig can0 up up

On board 1:

$ candump can0

On board 2:

$ cansend can0 500#1E.10.10