Category Archives: VoCore

VoCore2: WiFi Driver for Linux 4.9(LEDE latest version)

I have spend a lot of time on this, finally it is working perfect with latest LEDE!!
This firmware also enable sniffer/monitor mode for possible fun.

This driver is more stable than last time one for Linux 4.5, I have used iperf3 test one hour, average speed is greater than 40Mbps — one on board blue antenna, and over 50Mbps for one external antenna. Of course double external antennas will be much faster.

firmware with blob here:
md5: 9a7ef2de60713cfb7c951ba4a6a92b81

mt7628.ko: for Linux 4.9
iwpriv and iwconfig:

mt7628.dat: used to config wifi kernel. uncompress and put it to /etc, link here

mt7628.dat should in this path /etc/wireless/mt7628/mt7628.dat

PS: unfortunately, because of MTK NDA, I can not public its source code.

How to use?
First of all: insmod mt7628

1. Enable wifi AP mode:

ifconfig ra0 up
brctl addif br-lan ra0

2. Enable monitor/sniffer mode(I never use sniffer mode before, maybe it works)

ifconfig mon0 up

3. Enable STA mode…(this need compile iwpriv into the firmware, I did not try)

iwpriv ra0 set SiteSurvey=1
sleep 1
iwpriv ra0 set SiteSurvey=0
iwpriv ra0 get_site_survey

iwpriv ra0 set Channel=11 (must same as your AP, this value can get from "iwpriv ra0 get_site_survey")
iwpriv apcli0 set ApCliEnable=0
iwpriv apcli0 set ApCliAuthMode=WPA2PSK (normally WPA2 personal we use this setting)
iwpriv apcli0 set ApCliEncrypType=AES
iwpriv apcli0 set ApCliSsid=[YOUR SSID]
iwpriv apcli0 set ApCliWPAPSK=[YOUR SSID PASSWORD]
iwpriv apcli0 set ApCliEnable=1

make uci work with this driver. Currently have to manually insert the driver and start up it. :p

VoCore2: Wireless Driver for Linux 4.9

xxxx, LEDE Linux 4.9 kernel has changed a lot! Transport MediaTek wireless driver is very painful this time, part of the code have to be rewriten. :'(

PS: I think MTK should hire me for transport driver to openwrt/LEDE, I guess I know the driver even better than some of their engineers, lol :p

monitor mode, multi SSID, mesh network, and various of packages… everything is that delicious…attract me spend my time, have to work harder ๐Ÿ™‚

VoCore2: remote debug with GDB

I love command line recently, Eclipse might be easy to use(I do not like Java complex depends), Qt creator looks nice(this is my favorite IDE), but command line, the GDB, is their core.

First, let’s compile gdb…
This article is focus on cross-compile. (I do not think you can compile gdb on VoCore2 magically ๐Ÿ™‚

Once you compile openwrt or LEDE on your host linux computer, it already have gdb(mipsel-openwrt-linux-uclibc-gdb), but it has a bug, when you run it later it will report “Remote ‘g’ packet reply is too long”. This is easy to fix, we need to modify gdb Makefile, in openwrt/toolchain/gdb/Makefile, section “Host/Configure”, add “–with-expat” to CFLAGS. Better to delete old compiled gdb file in build_dir.

You might also need to install expat lib, call “apt-get install libexpat-dev”

Then compile…

Now let’s make a simple app to debug
I’d like to use “mem”, this small app is used to read and write to memory directly. I use it to develop driver and do quick hack to the kernel.
Source code is here: Link to Source

Uncompress it and get mem.c

Next step, compile it with debug information
One command line will do this, do not forget -g, it is used to generate debug links.

mipsel-openwrt-linux-uclibc-gcc -g mem.c -o mem

Make gdbserver
In openwrt “make menuconfig”, Development section, select gdbserver.
Compile and install gdbserver to your VoCore.
Also you can copy mem to your VoCore.

We can happy debug
On VoCore2, run command

gdbserver ./mem

On your host, run command

mipsel-openwrt-linux-uclibc-gdb ./mem
(gdb) set sysroot ~/openwrt/staging_dir/toolchain-mipsel_24kec+dsp_gcc-4.8-linaro_uClibc-
(gdb) target remote

Now we can use gdb command:

r: run the app.
l: show source code list.
b: add break point, parameter is the line number.
ni: step over one line.
si: step in one line.
p: show the parameter value.
d: delete break point.
i b: show current break point.
c: continue and run to next break point.

VoCore2: Login to Terminal from Browser

1. Download the package Makefile from, current version it is 2.19.

2. Put it in openwrt source/package/utils

3. Call “make menuconfig”, select shellinabox in Network submenu.

4. Compile openwrt, and upgrade VoCore2 firmware.

5. Connect to VoCore2 by wire or wifi, now we can login to it from browser

Good luck!

VoCore2: New Dock with microUSB Ethernet!

I made another dock for VoCore2 Ultimate, added on board USB to Ethernet to replace old on board USB to TTL, this alter will make VoCore2 more flexble.

Currently the microUSB port is not only for power, but also it is another ethernet port(using port 1).

Once we connect it to computer, we can debug VoCore2 by USB LAN10/100, much faster and more stable.

PS: USB2TTL is removed from dock but still able to use an external device connect to UART0 for the console debug.

Now we can have more advanced usage:

ifconfig will find this device once it is connect to your Linux/MacOS computer.(Windows should be same)

	ether 00:e0:3c:36:e2:xx
	inet6 fe80::10ad:1794:b44f:59xx%en7 prefixlen 64 secured scopeid 0xf 
	inet6 fdac:96e9:9938::1874:61ba:9aca:6axx prefixlen 64 autoconf secured 
	inet6 fdac:96e9:9938::f85f:93f7:4c10:82xx prefixlen 64 autoconf temporary 
	inet netmask 0xffffff00 broadcast
	nd6 options=201<PERFORMNUD,DAD>
	media: autoselect (100baseTX)
	status: active

It allocedย for my computer.
This dock is specially for portable router, VPN connection.

Its shape is exactly same as VoCore2 Ultimate. ๐Ÿ™‚
Here is the raw dock, based on RTL8152

VoCore2 Tips

1. Switch port0 between “wan” and “lan”

change in VoCore2, /etc/config/network, first vlan is lan ports, second vlan is wan port, put 0 into second one, port0 will become lan port.

config switch_vlan
    option ports '0 2 3 4 6t'

config switch_vlan
    option ports '1 6t'

2. Restart wifi in console.


3. Clean memory of VoCore2 for long time usage.

sync && echo 3 > /proc/sys/vm/drop_caches

4. Play radio with VoCore2 Ultimate

(sleep 5;wget -O - | madplay -)&

(Canada Radio ๐Ÿ™‚

5. Add password for UART console.

modify /etc/inittab

::askconsole:/bin/ash --login

note: make sure busybox enable login command when compile busybox.

6. Windows7 or lower system can not install driver for USB2TTL
check this link: Connecting to the serial console on Windows 7


Special Thanks

Patrick Coutu (contribute 3, 4)
Noble Pepper (contribute 6)

VoCore2: Control RGB(WS2812B) LEDs

Now we can use VoCore2 control WS2812B based LED belt ๐Ÿ™‚ Hope this helps you make a beautiful house.

This is a “big” project for me, it contains three parts.

  • Linux Driver
    I am using I2S interface, because the best timer on VoCore2 is 1us… WS2812 requests 800KHz, and its bit0, bit1 is special: 800ns high then 400ns low, it is its bit1, 400ns high then 800ns low it is its bit0. We can not use timer to output that.
    But There is a super good channel, it is I2S. I2S speed is up to 240MHz. I find a way to use three I2S bits to simulate one WS2812 bit, set I2S speed to 2400KHz. ๐Ÿ™‚
    PS: I spend some time rewrite dma driver, so data is transfer from dma and VoCore2 is able to control 1024 LEDs at 30fps using less than 1% cpu.
  • API for user space
    I2S interface is not designed for such “common” usage, it is used to transfer audio data, so it is align with double word(4 byte), and have its special byte order, we can not send “abc” to I2S directly, because I2S real output will be “c?ab”. To use I2S interface, an API convert data order is necessary.
  • Hardware design.
    VoCore2 signal output voltage is 3.3V, WS2812B min signal voltage is 0.7 x Vcc = 3.5V, not match well. We’d better to use a buffer gate to convert the signal voltage for the accurate situation. This is option, without gate it still work, just sometime one or two LEDs are naughty. Connection is simple, I2S_SDO to WS2812B DATAIN.

โ€œThere is no secret in the source code.โ€

First is Linux Driver Code: ws2812b.c, put it into Linux kernel and add it to Makefile and Kconfig, also enable gdma at VOCORE2.dts, compile. If it works normal, it will create a system file at /sys/devices/10000000.palmbus/10002800.gdma/update

You can try “echo aaaa > /sys/devices/10000000.palmbus/10002800.gdma/update”, I2S_SDO will output wave like this:

PS: actually I2S received data is “aaaa\r”

Then API Source Code:ย ws2812_api

ws2812_reset(): call this to turn all LEDs off RGB(0,0,0).
ws2812_set(int *color, int size): set leds colors. example: you have 16 WS2812B in a line, you want to set them to different color, code should be like this (include ws2812.h)

		int color[] = {0x080000, 0x000800, 0x000008,
		               0x080000, 0x000800, 0x000008,
		               0x080000, 0x000800, 0x000008,
		               0x080000, 0x000800, 0x000008,
		               0x080000, 0x000800, 0x000008,
		ws2812_set(color, sizeof(color) / sizeof(int));

For more details, check unit test code atย the end ofย ws2812.c.
The head photo is from this code ๐Ÿ™‚ For me everything works well.