How to use & access OpenRex peripherals (Examples)

DDR3 Memory test

First check how much free memory you have (we used 2GB OpenRex version):

free

total used free shared buffers cached

Mem: 1805768 236512 1569256 0 7584 132584

-/+ buffers/cache: 96344 1709424

Swap: 0 0 0

To run the memory test use as much free memory as you can:

# memtester 480M

memtester version 4.3.0 (32-bit)

Licensed under the GNU General Public License version 2 (only).

pagesize is 4096

pagesizemask is 0xfffff000

want 480MB (503316480 bytes)

got 480MB (503316480 bytes), trying mlock ...locked.

Loop 1:

Stuck Address : ok

Random Value : ok

Compare XOR : ok

Compare SUB : ok

Compare MUL : ok

Compare DIV : ok

Compare OR : ok

Compare AND : ok

Sequential Increment: ok

Solid Bits : ok

Block Sequential : ok

Checkerboard : ok

Bit Spread : ok

Bit Flip : ok

Walking Ones : ok

Walking Zeroes : ok

8-bit Writes : ok

16-bit Writes : ok

Ethernet test

A simple ping test. You can increase the size of the packet (press -s switch) an specify number of packets (use -c switch):

# ping -c 5 -s 1000 192.168.0.80

PING 192.168.0.80 (192.168.0.80) 1000(1028) bytes of data.

1008 bytes from 192.168.0.80: icmp_req=1 ttl=64 time=0.358 ms

1008 bytes from 192.168.0.80: icmp_req=2 ttl=64 time=0.280 ms

1008 bytes from 192.168.0.80: icmp_req=3 ttl=64 time=0.333 ms

1008 bytes from 192.168.0.80: icmp_req=4 ttl=64 time=0.271 ms

1008 bytes from 192.168.0.80: icmp_req=5 ttl=64 time=0.338 ms

--- 192.168.0.80 ping statistics ---

5 packets transmitted, 5 received, 0% packet loss, time 3996ms

rtt min/avg/max/mdev = 0.271/0.316/0.358/0.034 ms

You can also test the Ethernet by downloading a big file form a remote server:

wget http://www.imx6rex.com/rex-uploads/imx6rex-xubuntu-13-04-production-04-AUG-2014.tar

--2016-02-09 11:17:04-- http://www.imx6rex.com/rex-uploads/imx6rex-xubuntu-13-04-production-04-AUG-2014.tar

Resolving www.imx6rex.com (www.imx6rex.com)... 54.83.203.118

Connecting to www.imx6rex.com (www.imx6rex.com)|54.83.203.118|:80... connected.

HTTP request sent, awaiting response... 200 OK

Length: 627334028 (598M) [application/x-tar]

Saving to: imx6rex-xubuntu-13-04-production-04-AUG-2014.tar

100%[======================================>] 627,334,028 2.24MB/s in 7m 56s

2016-02-09 11:25:01 (1.26 MB/s) - imx6rex-xubuntu-13-04-production-04-AUG-2014.tar saved [627334028/627334028]

USB

Plug in a USB memory stick, and use dmesg command. You will see a message like this:

# dmesg | tail

usb 2-1.2: new high speed USB device number 5 using fsl-ehci

scsi1 : usb-storage 2-1.2:1.0

scsi 1:0:0:0: Direct-Access TOSHIBA TransMemory 1.00 PQ: 0 ANSI: 4

sd 1:0:0:0: [sdb] 30297216 512-byte logical blocks: (15.5 GB/14.4 GiB)

sd 1:0:0:0: [sdb] Write Protect is off

sd 1:0:0:0: [sdb] Mode Sense: 45 00 00 00

sd 1:0:0:0: [sdb] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA

sdb: sdb1

sd 1:0:0:0: [sdb] Attached SCSI removable disk

Mount the USB (in this example the USB is formatted as FAT)

# mount /dev/sdb1 /media/usb0

# ls -la /media/usb0

total 3590620

drwxr-xr-x 11 root root 8192 Jan 1 1970 .

drwxr-xr-x 9 root root 4096 Feb 8 10:11 ..

-rwxr-xr-x 1 root root 27230208 Jul 20 2015 blackbird.wav

drwxr-xr-x 2 root root 8192 Jan 1 1980 BMP

drwxr-xr-x 2 root root 8192 Sep 8 15:57 EMC-8-sep

drwxr-xr-x 2 root root 8192 Sep 3 15:55 emc-testing

drwxr-xr-x 2 root root 8192 Jul 20 2015 env-chamber-testing

-rwxr-xr-x 1 root root 2466408942 Jun 13 2014 imx6rex-xubuntu-13-04-ogre-13-JUN-2014.tar

-rwxr-xr-x 1 root root 606266482 Apr 5 2014 imx6rex-xubuntu-13-04.tar

drwxr-xr-x 2 root root 8192 Feb 7 16:36 openrex

-rwxr-xr-x 1 root root 8388608 Jan 1 1980 tmp-file1

Now, you can copy a video to /media and play it. This will perform a simple USB test.

SD

You can follow a similar approach when testing SD card as used for USB memory stick. You can list the connected storage devices:

# fdisk -l

Disk /dev/mmcblk0: 7948 MB, 7948206080 bytes

81 heads, 10 sectors/track, 19165 cylinders, total 15523840 sectors

Units = sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x00000000

Device Boot Start End Blocks Id System

/dev/mmcblk0p1 10 15523649 7761820 83 Linux

Preparing SD card for a filesystem

These steps described creating a filesystem on a new SD card for the OpenRex board. Download the filesystem, the default kernel. Be sure, you have the latest files. Copy all the files to your host machine (we use Ubuntu 9.04), the computer where you will be preparing the SD card.

Check if the card was successfully plugged in:

# dmesg | tail

[813850.046729] sd 7:0:0:0: [sdb] Write Protect is off

[813850.046732] sd 7:0:0:0: [sdb] Mode Sense: 03 00 00 00

[813850.046733] sd 7:0:0:0: [sdb] Assuming drive cache: write through

[813850.054749] sd 7:0:0:0: [sdb] 15523840 512-byte hardware sectors: (7.94 GB/7.40 GiB)

[813850.061263] sd 7:0:0:0: [sdb] Write Protect is off

[813850.061265] sd 7:0:0:0: [sdb] Mode Sense: 03 00 00 00

[813850.061267] sd 7:0:0:0: [sdb] Assuming drive cache: write through

[813850.061272] sdb: sdb1

[813850.072395] sd 7:0:0:0: [sdb] Attached SCSI removable disk

[813850.072443] sd 7:0:0:0: Attached scsi generic sg2 type 0

Be sure your SD card is not mounted. Now run partition manager (in our case the card is mapped as /dev/sdb) and create a new partition:

# fdisk /dev/sdb

The number of cylinders for this disk is set to 19165.

There is nothing wrong with that, but this is larger than 1024,

and could in certain setups cause problems with:

1) software that runs at boot time (e.g., old versions of LILO)

2) booting and partitioning software from other OSs

(e.g., DOS FDISK, OS/2 FDISK)

Command (m for help): p

Disk /dev/sdb: 7948 MB, 7948206080 bytes

81 heads, 10 sectors/track, 19165 cylinders

Units = cylinders of 810 * 512 = 414720 bytes

Disk identifier: 0x00000000

Device Boot Start End Blocks Id System

/dev/sdb1 1 19165 7761820 83 Linux

Command (m for help): d

Selected partition 1

Command (m for help): n

Command action

e extended

p primary partition (1-4)

Partition number (1-4): 1

First cylinder (1-19165, default 1):

Using default value 1

Last cylinder, +cylinders or +size{K,M,G} (1-19165, default 19165):

Using default value 19165

Command (m for help): w

The partition table has been altered!

Calling ioctl() to re-read partition table.

Syncing disks.

Format the partition:

# mkfs.ext3 /dev/sdb1

mke2fs 1.41.4 (27-Jan-2009)

Filesystem label=

OS type: Linux

Block size=4096 (log=2)

Fragment size=4096 (log=2)

485760 inodes, 1940455 blocks

97022 blocks (5.00%) reserved for the super user

First data block=0

Maximum filesystem blocks=1988100096

60 block groups

32768 blocks per group, 32768 fragments per group

8096 inodes per group

Superblock backups stored on blocks:

32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632

Writing inode tables: done

Creating journal (32768 blocks): done

Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 39 mounts or

180 days, whichever comes first. Use tune2fs -c or -i to override.

SD card is now prepared for copying the files. Mount it:

mount /dev/sdb1 /media/sdcard

cd /media/sdcard

Unpack the filesystem:

tar -pxvzf /home/fedevel/imx6rex-xubuntu-13-04-production-04-AUG-2014.tar

Now copy the kernel to the SD card:

cp -prv /home/fedevel/openrex/uImage .

Unmout the USB stick and the SD card is ready to work with:

umount /media/sdcard

You can remove the SD card and try it in an OpenRex board.

Listing SD card files in u-boot

You can check the content of the SD card in the u-boot with this command:

mmc dev 0; ext2ls mmc 0

HDMI

To setup the HDMI monitor as a default video output (e.g. x window will be shown here) put following environment setup in u-boot. Use SD card which you have prepared in this section:

setenv bootargs 'console=ttymxc0,115200'

setenv bootcmd_mmc 'run bootargs_mmc; mmc dev 0; ext2load mmc 0 0x10800000 uImage 3850000; bootm 0x10800000'

setenv bootargs_mmc 'setenv bootargs ${bootargs} ip=dhcp root=/dev/mmcblk0p1 rootwait video=mxcfb0:dev=hdmi,1280x720M@60,if=RGB666 vmalloc=400M fbmem=28M fbcon=28M'

run bootcmd_mmc

Setup the HDMI monitor as primary when the filesystem is downloaded from network server:

setenv bootargs_nfs 'setenv bootargs ${bootargs} root=/dev/nfs rootdelay=4 ip=192.168.0.85:::255.255.255.0 nfsroot=${serverip}:${nfsroot},v3,tcp video=mxcfb0:dev=hdmi,1280x720M@60,if=RGB24 vmalloc=400M fbmem=28M fbcon=28M'

Start the X-session on HDMI from the console (Note: These commands may not work on every filesystem - tested with Ubuntu 13.04)

export DISPLAY=:0.0

startx &

Play a video on HDMI monitor:

# mplayer -vo fbdev2 /home/ubuntu/Clouds.avi

mplayer: could not connect to socket

mplayer: No such file or directory

Failed to open LIRC support. You will not be able to use your remote control.

Playing /home/ubuntu/Clouds.avi.

libavformat version 53.21.1 (external)

Mismatching header version 53.19.0

AVI file format detected.

[aviheader] Video stream found, -vid 0

VIDEO: [DIVX] 1024x576 24bpp 25.000 fps 3066.1 kbps (374.3 kbyte/s)

Clip info:

Software: MEncoder 0.90rc5-3.2.2

Load subtitles in /home/ubuntu/

==========================================================================

Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family

libavcodec version 53.35.0 (external)

Mismatching header version 53.32.2

Unsupported PixelFormat 61

Unsupported PixelFormat 53

Unsupported PixelFormat 81

Selected video codec: [ffodivx] vfm: ffmpeg (FFmpeg MPEG-4)

==========================================================================

Audio: no sound

Starting playback...

Could not find matching colorspace - retrying with -vf scale...

Opening video filter: [scale]

Movie-Aspect is 1.78:1 - prescaling to correct movie aspect.

[swscaler @ 0x2b2e0980]No accelerated colorspace conversion found from yuv420p to bgra.

[swscaler @ 0x2b2e0980]using unscaled yuv420p -> bgra special converter

VO: [fbdev2] 1024x576 => 1024x576 BGRA

V: 42.4 1062/1062 61% 25% 0.0% 0 0

Exiting... (End of file)

Play a video on HDMI monitor when not set as a default monitor (by u-boot). List all the mapped displays:

# cat /proc/cmdline; for fb in /sys/class/graphics/fb?; do echo "----$fb"; cat $fb/name; cat $fb/mode; cat $fb/fsl_disp_*; done

According to the listed devices, find the HDMI monitor (in this case located in fb0) and enable it (or disable):

// enable fb0 display

echo 0 > /sys/class/graphics/fb0/blank

// disable fb0 display

echo 1 > /sys/class/graphics/fb0/blank

The device, where the video will be played, needs to be specified (in this case /dev/fb0). Play a video in a loop on selected monitor:

mplayer -vo fbdev2:/dev/fb0 -vf scale -zoom -loop 0 -xy 1024 /home/ubuntu/Clouds.avi

Booting from a SATA hard drive

Plug in the SATA device with copied filesystem (you can use SD card section - it is very similar). Note that we still need an SD card for kernel image. Reset the board, stop autoboot and put these settings into u-boot:

setenv bootargs 'console=ttymxc0,115200'

setenv bootcmd_sata 'run bootargs_sata; mmc dev 0; ext2load mmc 0 0x10800000 uImage 3850000; bootm 0x10800000'

setenv bootargs_sata 'setenv bootargs ${bootargs} ip=dhcp root=/dev/sda1 rootwait video=mxcfb0:dev=hdmi,1280x720M@60,if=RGB666 vmalloc=400M fbmem=28M fbcon=28M'

run bootcmd_sata

Now you will boot up using filesystem form SATA hard drive.

Wifi PCIE mini card Intel 4965AGN

Enable WiFi support in menuconfig:

make ARCH=arm CROSS_COMPILE=/opt/freescale/usr/local/gcc-4.6.2-glibc-2.13-linaro-multilib-2011.12/fsl-linaro-toolchain/bin/arm-none-linux-gnueabi- menuconfig

//enable PCIE support

Add a star to: make menuconfig -> System Type -> Freescale MXC Implementations ->; PCI Express support

Add a star to: make menuconfig -> Bus support -> Message Signaled Interrupts (MSI and MSI-X)

Add a star to: make menuconfig -> Bus support -> PCI Express support

//enable iwl4965 support

Add a star to: make menuconfig -> Networking support -> Wireless -> Generic IEE 802.11 Netwroking Stack (mac80211)

Add a star to: make menuconfig -> Device Drivers -> Network device support -> Wireless LAN -> Intel Wireless Wifi 4965AGN (iwl4965)

//disable FEC (the on board ethernet)

Remove the star from: make menuconfig -> Device Drivers -> Network device support -> Ethernet (10 or 100Mbit)

Compile the new kernel:

make ARCH=arm CROSS_COMPILE=/opt/freescale/usr/local/gcc-4.6.2-glibc-2.13-linaro-multilib-2011.12/fsl-linaro-toolchain/bin/arm-none-linux-gnueabi- uImage

While new kernel is beeing compiled, run OpenRex with standard kernel supporting wired ethernet. Provide a Wifi firmware for the card:

wget http://www.imx6rex.com/wp-content/uploads/2014/03/iwlwifi-4965-ucode-228.61.2.24.tar

tar -xvf iwlwifi-4965-ucode-228.61.2.24.tar

cd iwlwifi-4965-ucode-228.61.2.24

cp -prv iwlwifi-4965-2.ucode /lib/firmware/

Turn off your board. Plug in Wifi card (with plugged antenna in the ports 1 and 3). Copy new kernel with 4965AGN support to the SD card and boot up.

Check if you can see your Wifi. It should look like this:

# lspci

00:00.0 PCI bridge: Device 16c3:abcd (rev 01)

01:00.0 Network controller: Intel Corporation PRO/Wireless 4965 AG or AGN [Kedron] Network Connection (rev 61)

Configure Wifi. First create this file (be sure you are in the iwlwifi directory:

cd /home/ubuntu/iwlwifi-4965-ucode-228.61.2.24

nano wpa.conf

Insert your Wifi information there (replace ssid and psk with your Wifi settings):

network={

ssid="wifinetworkname"

psk="wifipassword"

}

Note: My router settings are - WPA PSK, aes ccm, WPA pre-shared key Run:

wpa_supplicant -B -Dwext -iwlan0 -cwpa.conf

Now obtain an IP address for the card. We use dhcp server:

dhclient -v -r wlan0

dhclient -v wlan0

If your router does not support dhcp, you can setup a static IP (addresses may be different for your network):

ifconfig wlan0 192.168.110.120

route add -net 0.0.0.0 netmask 0.0.0.0 gw 192.168.110.1

If the ping is not working, update DNS settings. Open:

sudo nano /etc/resolv.conf

and update nameserver to:

nameserver 8.8.8.8

Try to ping google:

# ping www.google.com

PING www.google.com (62.197.198.223) 56(84) bytes of data.

64 bytes from cache.google.com (62.197.198.223): icmp_req=1 ttl=58 time=3.85 ms

64 bytes from cache.google.com (62.197.198.223): icmp_req=2 ttl=58 time=3.65 ms

64 bytes from cache.google.com (62.197.198.223): icmp_req=3 ttl=58 time=3.76 ms

This is how it should look when everything is configured properly:

# iwconfig

lo no wireless extensions.

wlan0 IEEE 802.11abgn ESSID:"s15as"

Mode:Managed Frequency:2.412 GHz Access Point: D4:CA:6D:6B:64:57

Bit Rate=65 Mb/s Tx-Power=15 dBm

Retry long limit:7 RTS thr:off Fragment thr:off

Encryption key:off

Power Management:off

Link Quality=70/70 Signal level=-28 dBm

Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0

Tx excessive retries:431758 Invalid misc:1061 Missed beacon:0

We can also have check, if the IP address was obtained successfully:

# ifconfig

lo Link encap:Local Loopback

inet addr:127.0.0.1 Mask:255.0.0.0

UP LOOPBACK RUNNING MTU:16436 Metric:1

RX packets:41 errors:0 dropped:0 overruns:0 frame:0

TX packets:41 errors:0 dropped:0 overruns:0 carrier:0

collisions:0 txqueuelen:0

RX bytes:4376 (4.3 KB) TX bytes:4376 (4.3 KB)

wlan0 Link encap:Ethernet HWaddr 00:13:e8:44:2b:51

inet addr:192.168.120.99 Bcast:192.168.120.255 Mask:255.255.255.0

UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

RX packets:413848 errors:0 dropped:0 overruns:0 frame:0

TX packets:597649 errors:0 dropped:0 overruns:0 carrier:0

collisions:0 txqueuelen:1000

RX bytes:205022775 (205.0 MB) TX bytes:823018797 (823.0 MB)

Now we can try to download a file through Wifi:

# wget http://www.imx6rex.com/wp-content/uploads/2016/02/OpenRex-Picture-1400px.jpg

--1970-01-01 00:43:40-- http://www.imx6rex.com/wp-content/uploads/2016/02/OpenRex-Picture-1400px.jpg

Resolving www.imx6rex.com (www.imx6rex.com)... 54.83.203.118

Connecting to www.imx6rex.com (www.imx6rex.com)|54.83.203.118|:80... connected.

HTTP request sent, awaiting response... 200 OK

Length: 299174 (292K) [image/jpeg]

Saving to: ‘OpenRex-Picture-1400px.jpg’

100%[======================================>] 299,174 409KB/s in 0.7s

1970-01-01 00:43:41 (409 KB/s) - ‘OpenRex-Picture-1400px.jpg’ saved [299174/299174]

Disconnect the onboard ethernet and test network performance. The speed will wary depending on distance, type or number of antennae. We will use iperf tool:

sudo apt-get install iperf

Now we can test the connection:

//start iperf server, on a local computer

$ iperf -s

//start iper client on the OpenRex board

# iperf -c 192.168.10.90 -t 60 -i 10

------------------------------------------------------------

Client connecting to 192.168.10.90, TCP port 5001

TCP window size: 16.0 KByte (default)

------------------------------------------------------------

[ 3] local 192.168.120.99 port 59475 connected with 192.168.10.90 port 5001

[ ID] Interval Transfer Bandwidth

[ 3] 0.0-10.0 sec 26.5 MBytes 22.2 Mbits/sec

[ 3] 10.0-20.0 sec 28.6 MBytes 24.0 Mbits/sec

[ 3] 20.0-30.0 sec 26.8 MBytes 22.4 Mbits/sec

[ 3] 30.0-40.0 sec 26.5 MBytes 22.2 Mbits/sec

[ 3] 40.0-50.0 sec 28.8 MBytes 24.1 Mbits/sec

[ 3] 50.0-60.0 sec 30.1 MBytes 25.3 Mbits/sec

[ 3] 0.0-60.1 sec 167 MBytes 23.4 Mbits/sec

and the other direction

//start iperf server on the OpenRex board

# iperf -s

//start iperf client on a local computer

$ iperf -c 192.168.120.99 -t 60 -i 10

------------------------------------------------------------

Client connecting to 192.168.120.99, TCP port 5001

TCP window size: 16.0 KByte (default)

------------------------------------------------------------

[ 3] local 192.168.10.90 port 43385 connected with 192.168.120.99 port 5001

[ ID] Interval Transfer Bandwidth

[ 3] 0.0-10.0 sec 23.1 MBytes 19.4 Mbits/sec

[ 3] 10.0-20.0 sec 22.4 MBytes 18.8 Mbits/sec

[ 3] 20.0-30.0 sec 21.6 MBytes 18.1 Mbits/sec

[ 3] 30.0-40.0 sec 22.1 MBytes 18.6 Mbits/sec

[ 3] 40.0-50.0 sec 21.5 MBytes 18.0 Mbits/sec

[ 3] 50.0-60.0 sec 22.4 MBytes 18.8 Mbits/sec

[ 3] 0.0-60.3 sec 133 MBytes 18.5 Mbits/sec

Audio SGTL5000

During the testings we used Genius HS-M04SU headphones.

Access to audio mixer:

alsamixer

You can adjust Headphones gain (the first column). Play a wav file:

aplay -D hw:0,0 /home/ubuntu/blackbird.wav

Record audio from microphone

Before recording open alsamixer again and set the audio input source. Move with left arrow and find Capture Mux column. Be sure you set "MIC_IN" option. You can also adjust Microphone gain and Capture Attenuate Switch. Connect 4-pole headphones with microphone and run:

arecord -f dat -d 10 -D hw:0,0 test.wav

Play the recorded file:

aplay -f dat test.wav

I2C

We will list all the devices on the I2C1 bus:

# i2cdetect 0

WARNING! This program can confuse your I2C bus, cause data loss and worse!

I will probe file /dev/i2c-0.

I will probe address range 0x03-0x77.

Continue? [Y/n]

0 1 2 3 4 5 6 7 8 9 a b c d e f

00: -- -- -- -- -- -- -- -- -- -- -- -- --

10: -- -- -- -- -- -- -- -- -- -- -- -- 1c -- -- --

20: 20 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

50: -- -- -- -- -- -- -- 57 -- -- -- -- -- -- -- --

60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

70: -- -- -- -- -- -- -- --

Here are the devices which can be sees on I2C1 bus (without any external board):

7-bit address Peripheral

0x1C Compass + Accelerometer

0x20 Gyroscope

0x57 EEPROM

Microcontroller which is connected to this bus, but is not visible, needs to have enabled I2C operation first. Another chip is PMIC and we removed bypass resistor during PMIC programming on this board.

We also check for peripherals on I2C2 bus:

# i2cdetect 1

WARNING! This program can confuse your I2C bus, cause data loss and worse!

I will probe file /dev/i2c-1.

I will probe address range 0x03-0x77.

Continue? [Y/n]

0 1 2 3 4 5 6 7 8 9 a b c d e f

00: -- -- -- -- -- -- -- UU -- -- -- -- --

10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

30: 30 -- -- -- -- -- -- 37 -- -- -- -- -- -- -- --

40: 40 -- -- -- -- -- -- -- 48 -- 4a 4b -- -- -- --

50: UU -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

70: -- -- -- -- -- -- -- --

I2C2 devices which are available:

7-bit address Peripheral

0x0a Audio codec

0x30 HDMI monitor

0x40 Humidity sensor

0x48 Temperature sensor

0x50 CPU HDMI EDID

I2C3 bus is dedicated for external connection, so there are no devices to be found yet.

Using this simple command we checked that all the devices placed on I2C buses are working and responding. This is just a very simple test but you are now sure that power rails for peripherals are OK and you haven't swap SCL and SDA signals. :)

EEPROM

We use a standard 24 family EEPROM memory with capacity of 2K and 8-bit programming. Simply we can test it with i2c-tool by writing data to it:

i2cset -y 0 0x57 0x00 0xfe

i2cset -y 0 0x57 0x01 0xde

i2cset -y 0 0x57 0x02 0x7e

i2cset -y 0 0x57 0x03 0x1f

We can check if we wrote the bytes correctly:

# i2cdump -y -r 0-0x0f 0 0x57

0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef

00: fe de 7e 1f ff ff ff ff ff ff ff ff ff ff ff ff ??~????.........

Writing a file into EEPROM memory

If we would like to write a file, we can use eeprog program to do that (use this version instead which includes files support):

wget http://darkswarm.org/eeprog-0.7.6-tear5.tar.gz

tar -zxvf eeprog-0.7.6-tear5.tar.gz

cd eeprog-0.7.6-tear12/

Build the tool:

# make

cc -g -Wall -O2 -c -o eeprog.o eeprog.c

cc -g -Wall -O2 -c -o 24cXX.o 24cXX.c

cc eeprog.o 24cXX.o -o eeprog

We can prepare a simple text file which will be written into EEPROM:

echo 'Testing EEPROM write/read' > test_write.txt

And now we are ready to program:

# ./eeprog /dev/i2c-0 0x57 -8 -t 5 -i test_write.txt -f -w 0x00

eeprog 0.7.6-tear12, a 24Cxx EEPROM reader/writer

Bus: /dev/i2c-0, Address: 0x57, Mode: 8bit

Operation: write at offset 0, Input file: test_write.txt

Write cycle time: 5 milliseconds

Writing test_write.txt starting at address 0x0

............................

We can read the data back:

# ./eeprog /dev/i2c-0 0x57 -8 -o test_read.txt -xf -r 0x00:0x30

eeprog 0.7.6-tear12, a 24Cxx EEPROM reader/writer

Bus: /dev/i2c-0, Address: 0x57, Mode: 8bit

Operation: read 48 bytes from offset 0, Output file: test_read.txt

Reading 48 bytes from 0x0

Now we will convert the hex file into ASCII characters and check it:

# cut -c 8- test_read.txt | xxd -r -p

Testing EEPROM write/read

Wireless Modem (Telit HE910 PCIE mini)

Enable modem support in menuconfig:

make ARCH=arm CROSS_COMPILE=/opt/freescale/usr/local/gcc-4.6.2-glibc-2.13-linaro-multilib-2011.12/fsl-linaro-toolchain/bin/arm-none-linux-gnueabi- menuconfig

Add a star to: make menuconfig -> Device Drivers -> USB support -> USB Modem (CDC ACM) support

Install serial console e.g. picocom:

sudo apt-get install picocom

Insert SIM card and modem card. Plug the antennae into first 2 plugs from the right. Run serial console on the modem port:

picocom /dev/ttyACM3 -b 115200

Test network connection (here is a nice document with AT command examples):

AT+CPIN?

+CPIN: READY

AT+CREG?

+CREG: 0,1

AT+COPS?

+COPS: 0,0,"O2 - SK ",2

Now we can test if modem is working by dialing up number 0123456789 (do not forget to use semicolon after number). Then we will hang-up:

ATD0123456789;

ATH

You can close the terminal by pressing Ctrl+A and then Ctrl+X.

PMIC regulator

We created a page dedicated to PMIC testing and programming.

Flashing LPC13xx microcontroller

To program LPC13xx with a firmware, follow the steps below.

1) Download the ISP handler software and unpack it:

wget https://github.com/FEDEVEL/openrex-nxp-lpc13xx/archive/LPC1347.zip

unzip LPC1347.zip

cd openrex-nxp-lpc13xx-LPC1347/

2) Now you can test programming the microcontroller by using a simple script (be sure binary is located in the folder):

./openrex-isp-handler.sh LPC1347-userLED.bin

Go to our page about microcontroller programming and testing for more info. There you can also find how to prepare your own binary file.

Sensors

Here you can find information how we have tested all sensor which are part of the OpenRex board. To simply test all the sensors at once run this script:

# wget http://www.imx6rex.com/download/released-files/openrex/v1i1/firmware/openrex-sensors.sh

# chmod 777 openrex-sensors.sh

# ./openrex-sensors.sh

OpenRex Sensors Measurements

TMP101 CPU HTC21

Temperature [C] : 34 34 54

Rel. humidity [per] : 22

X Y Z

Angular rate [dps] : -3 5 0

Acceleration [mg] : -23 10 987

Magnetic field [uT] : -42 8 1624

Temperature sensor

Reading a temperature from TMP101 sensor, which we used, is very easy. The device consists of only four registers: 2 Bytes register for temperature value (address 0x00), configuration register (0x01) and 2x 2 Bytes register for setting up minimum (0x03) and maximum (0x02) alert threshold. Simply we can read from first register (use w for word readout):

i2cget 1 0x48 0x00 w

We got 0x002B and converting to decimal it is 43°C.

Now we are using default 9-bit resolution only. To increase the precision up to 0.0625°C, we can setup 12-bit ADC operation. We will set to one bits R1 a R0 in the configuration register:

# i2cget -y 1 0x48 0x01

0x80

# i2cset -y 1 0x48 0x01 0xE0

# i2cdump -y -r 0-0x07 1 0x48 w

0,8 1,9 2,a 3,b 4,c 5,d 6,e 7,f

00: 2035 ffe0 004b 0050 XXXX XXXX XXXX XXXX

Temperature register now stores 12-bit value 0x2035 and converted it is 53.125 °C . Now the calculation is a bit more complex: 0x35->53°C plus decimal number 0.125 (fraction of 0x2 from 0xF).

To simple read the precision format directly in °C you can use a command created by Fabio:

i2cget -f -y 1 0x48 0x00 w | mawk '{printf("%.1f\n", (a=(("0x"substr($1,5,2)substr($1,3,1))*0.0625))>128?a-256:a)}'

Note that the temperature has risen because of stressapptest running. In comparison for high performance tasks CPU temperature (76°C) was 25°C higher than the temperate close to an edge (52.5°C - where the sensor is located).

Humidity sensor

SHT21 humidity and temperature sensor which is placed on OpenRex, uses a direct I2C measurement. After we send a request, we need to read data bytes which are directly being transmitted from the sensor (they are not stored in any accessible register). Because the measurement is 2 bytes long, we could not use i2c-tools for initial testing (i2cget supports word mode read only if register address is specified).

We are going to access humidity sensor using Linux driver. Kernel 3.0.35 already includes driver file which we need (located at drivers/hwmon/sht21.c). We just to mark the driver to be compiled. Go to arch/arm/configs/imx6_defconfig and set

CONFIG_SENSORS_SHT21=y

or you can setup it through menuconfig:

make ARCH=arm CROSS_COMPILE=/opt/freescale/usr/local/gcc-4.6.2-glibc-2.13-linaro-multilib-2011.12/fsl-linaro-toolchain/bin/arm-none-linux-gnueabi- menuconfig

//enable SHT21 support

Add a star to: make menuconfig -> Device Drivers -> Hardware Monitoring support -> Sensiron humidity and temperature sensors. SHT21 and compat.

Now we need to add the sensor into i2c_board_info structure (located in file arch/arm/mach-mx6/board-mx6q_sabresd.c in our case):

static struct i2c_board_info mxc_i2c1_board_info[] __initdata = {

{

I2C_BOARD_INFO("sht21", 0x40),

Complile kernel and start the board. If we now run i2cdetect, we can see that the humidity sensor address is marked as under use:

# i2cdetect -y 1

0 1 2 3 4 5 6 7 8 9 a b c d e f

00: -- -- -- -- -- -- -- UU -- -- -- -- --

10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

30: 30 -- -- -- -- -- -- 37 -- -- -- -- -- -- -- --

40: UU -- -- -- -- -- -- -- 48 -- 4a 4b -- -- -- --

50: UU -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

70: -- -- -- -- -- -- -- --

Now we can read the measurement:

# cat /sys/bus/i2c/devices/1-0040/humidity1_input

25288

# cat /sys/bus/i2c/devices/1-0040/temp1_input

29223

After conversion we got 42% relative humidity and 31.5 °C. To avoid computing the values, we can use for example this simple script:

#!/bin/bash

# OpenRex SHT21 humidity sensor reading script

hum=$( cat /sys/bus/i2c/devices/1-0040/humidity1_input )

temp=$( cat /sys/bus/i2c/devices/1-0040/temp1_input )

hum_result=0

temp_result=0

hum_result=$(echo "-6+125*$hum/65536" | bc -l)

temp_result=$(echo "-46.85+175.72*$temp/65536" | bc -l)

echo "SHT21 measurement on "$(date +\%Y/\%m/\%d-\%T)

printf "Rel. humidity : %4.2f %%\n" $hum_result

printf "Temperature : %4.2f C\n" $temp_result

After we save it and setup a permission, we can try to read data once more:

# nano sht21-read.sh

# chmod 777 sht21-read.sh

# ./sht21-read.sh

SHT21 measurement on 2016/02/17-18:26:47

Rel. humidity : 41.17 %

Temperature : 32.60 C

Gyroscope

As a gyroscope we are using FXAS21002. Before we can obtain data from the sensor we need to enable it first. We will put the gyroscope into the active mode:

i2cset -y 0 0x20 0x13 0x02

Now we can simply read all the registers (measurement are stored in bytes 1 to 6):

# i2cdump -y -r 0-0x15 0 0x20

No size specified (using byte-data access)

0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef

00: ff ff e3 00 48 ff f5 9b 00 00 00 08 d7 00 00 00 ..?.H.??...??...

10: 00 01 2f 02 00 00

To print the measurement in more friendly way, we created a simple script. We read the registers, converted 2's complement if needed and displayed the values in degrees per second:

#!/bin/bash

# Gyroscope sensor reading script

# setup gyroscope settings

i2cset -y 0 0x20 0x13 0x02 # set active state

i2cset -y 0 0x20 0x0D 0x00 # set full-scale range

i2cset -y 0 0x20 0x15 0x00 # disable double range selection

nom_sens=62.5 # nominal sensitivity for 2000 dps range

echo "Gyroscope real-time measurement"

echo "Angular rate [dps]: X Y Z"

while true

# read gyroscope measurements

gyro_x=$(( $( i2cget -f -y 0 0x20 0x01 ) << 8 | $( i2cget -f -y 0 0x20 0x02 ) ))

gyro_y=$(( $( i2cget -f -y 0 0x20 0x03 ) << 8 | $( i2cget -f -y 0 0x20 0x04 ) ))

gyro_z=$(( $( i2cget -f -y 0 0x20 0x05 ) << 8 | $( i2cget -f -y 0 0x20 0x06 ) ))

# convert 2's complement if needed

if [ "$gyro_x" -gt 32768 ]; then

gyro_x=$(echo "(65536-$gyro_x)*(-1)" | bc -l)

if [ "$gyro_y" -gt 32768 ]; then

gyro_y=$(echo "(65536-$gyro_y)*(-1)" | bc -l)

if [ "$gyro_z" -gt 32768 ]; then

gyro_z=$(echo "(65536-$gyro_z)*(-1)" | bc -l)

# convert values to degrees per second

gyro_x=$(echo "$gyro_x*$nom_sens/1000" | bc -l)

gyro_y=$(echo "$gyro_y*$nom_sens/1000" | bc -l)

gyro_z=$(echo "$gyro_z*$nom_sens/1000" | bc -l)

printf " %4.0f %4.0f %4.0f \r" $gyro_x $gyro_y $gyro_z

sleep 0.1

done

Now we can save the script and run it:

nano orx-gyro.sh

chmod 777 orx-gyro.sh

./orx-gyro.sh

When you will be moving with your board you can see the change in angular momentum. In this example the board was rotating while touching on the board (in z axis):

Gyroscope real-time measurement

Angular rate [dps]: X Y Z

-3 5 109

Accelerometer & compass

Accelerometer sensor FXOS8700CQ, which we selected, has similar register structure as our gyroscope. Thus we will use the same approach and create a script.

At first we put the device into active state and then enabled hybrid mode where both sensors are active. Then we read the data and updated its format:

#!/bin/bash

# Accelerometer & magnetometer sensor reading script

# set active mode

i2cset -y 0 0x1C 0x02A 0x01

# enable both sensors

i2cset -y 0 0x1C 0x05B 0x03

acc_sens=0.244 # nominal sensitivity for 2g accelerometer mode

mag_sens=0.1 # nominal sensitivity for magnetometer

echo "Accelerometer and magnetometer real-time measurement"

echo " X Y Z"

while true

# read 14-bit acceleration measurements

acc_x=$(( $( i2cget -f -y 0 0x1C 0x01 ) << 6 | $( i2cget -f -y 0 0x1C 0x02 ) >> 2))

acc_y=$(( $( i2cget -f -y 0 0x1C 0x03 ) << 6 | $( i2cget -f -y 0 0x1C 0x04 ) >> 2))

acc_z=$(( $( i2cget -f -y 0 0x1C 0x05 ) << 6 | $( i2cget -f -y 0 0x1C 0x06 ) >> 2))

# read 16-bit magnetic measurements

mag_x=$(( $( i2cget -f -y 0 0x1C 0x01 ) << 8 | $( i2cget -f -y 0 0x1C 0x02 ) ))

mag_y=$(( $( i2cget -f -y 0 0x1C 0x03 ) << 8 | $( i2cget -f -y 0 0x1C 0x04 ) ))

mag_z=$(( $( i2cget -f -y 0 0x1C 0x05 ) << 8 | $( i2cget -f -y 0 0x1C 0x06 ) ))

# convert 2's complement if needed

if [ "$acc_x" -gt 8192 ]; then

acc_x=$(echo "(16384-$acc_x)*(-1)" | bc -l)

if [ "$acc_y" -gt 8192 ]; then

acc_y=$(echo "(16384-$acc_y)*(-1)" | bc -l)

if [ "$acc_z" -gt 8192 ]; then

acc_z=$(echo "(16384-$acc_z)*(-1)" | bc -l)

if [ "$mag_x" -gt 32768 ]; then

mag_x=$(echo "(65536-$mag_x)*(-1)" | bc -l)

if [ "$mag_y" -gt 32768 ]; then

mag_y=$(echo "(65536-$mag_y)*(-1)" | bc -l)

if [ "$mag_z" -gt 32768 ]; then

mag_z=$(echo "(65536-$mag_z)*(-1)" | bc -l)

# convert values

acc_x=$(echo "$acc_x*$acc_sens" | bc -l)

acc_y=$(echo "$acc_y*$acc_sens" | bc -l)

acc_z=$(echo "$acc_z*$acc_sens" | bc -l)

mag_x=$(echo "$mag_x*$mag_sens" | bc -l)

mag_y=$(echo "$mag_y*$mag_sens" | bc -l)

mag_z=$(echo "$mag_z*$mag_sens" | bc -l)

printf " Acceleration [mg]: %4.0f %4.0f %4.0f \n" $acc_x $acc_y $acc_z

printf " Magnetic Field [uT]: %4.0f %4.0f %4.0f \r" $mag_x $mag_y $mag_z

sleep 0.1

tput cuu 1

done

Now we can test the sensors:

# nano orx-acc-mag.sh

# chmod 777 orx-acc-mag.sh

# ./orx-acc-mag.sh

Accelerometer and magnetometer real-time measurement

X Y Z

Acceleration [mg]: -26 11 993

Magnetic Field [uT]: -38 8 1627

IR Receiver

On our board we are using a 3-pin infrared receiver TSOP38238. With this simple solution you can control the system with the vast majority of the remote controllers (which use 38kHz carrier frequency).

Before we can try it, we need to add a support into the kernel. We will follow a similar approach as it was used for Raspberry Pi boards (this tutorial also describes more details about building an IR software support). We will use an i.MX6 modification of this RPi driver made by Stephan and Rene. You can have a look on the modification which we have done on our Github.

As the first step we will add a new driver file into the Linux kernel. Open your Ubuntu machine, where you were compiling the source files and navigate to the main directory of OpenRex Linux.

Download driver file and save it as drivers/staging/lirc/lirc_openrex.c. Alternatively you can use wget and download it directly:

wget http://www.imx6rex.com/download/released-files/openrex/v1i1/firmware/lirc_openrex.c -P drivers/staging/lirc/

If you will use an external sensor connected to a different pad, you need to update the harcoded GPIO setting in the driver. Our IR receiver is connected to GPIO2_IO11:

#define MYGPIO IMX_GPIO_NR(2, 11)

Now we need to include this driver into LIRC Makefile. Open it (located at drivers/staging/lirc/Makefile) and add line:

obj-$(CONFIG_LIRC_OPENREX) += lirc_openrex.o

As the next step we will add a new configuration option into drivers/staging/lirc/Kconfig file:

config LIRC_OPENREX

tristate "Homebrew GPIO Port Receiver for OpenRex"

depends on LIRC

help

Driver for Homebrew GPIO Port Receiver for the OpenRex

As the last thing we need to enable the IR signal usage. Go to mx6q_sabresd_pads structure located in arch/arm/mach-mx6/board-mx6q_sabresd.h file and add here

// IR RECEIVER

MX6Q_PAD_SD4_DAT3__GPIO_2_11,

If you will use a different pin, have a look into the file arch/arm/mach-mx6/board-mx6q_sabresd.c. Check if your signal has not been already use by the kernel.

Now we need to select this new driver to be compiled into the kernel. Go to menuconfig and update:

make ARCH=arm CROSS_COMPILE=/opt/freescale/usr/local/gcc-4.6.2-glibc-2.13-linaro-multilib-2011.12/fsl-linaro-toolchain/bin/arm-none-linux-gnueabi- menuconfig

Add a star to: make menuconfig -> Device Drivers -> Multimedia support -> Remote controller adapters

Add a star to: make menuconfig -> Device Drivers -> Multimedia support -> Remote controller adapters -> Compile Remote Controller keymap modules (NEW)

Add a star to: make menuconfig -> Device Drivers -> Multimedia support -> Remote controller adapters -> Enable IR to LIRC bridge (NEW)

Add a star to: make menuconfig -> Device Drivers -> Staging drivers

Add a star to: make menuconfig -> Device Drivers -> Staging drivers -> Linux Infrared Remote Control IR receiver/transmitter drivers (NEW)

Add a star to: make menuconfig -> Device Drivers -> Staging drivers -> Linux Infrared Remote Control IR receiver/transmitter drivers (NEW) -> Homebrew GPIO Port Receiver for OpenRex (NEW)

Recompile the driver and run the board with it. You should see new LIRC driver beeing loaded as the board boots. You can check it with dmesg:

# dmesg | grep "LIRC" -i

lirc_dev: IR Remote Control driver registered, major 251

IR LIRC bridge handler initialized

lirc_openrex lirc_openrex.0: lirc_dev: driver lirc_openrex registered at minor = 0

lirc_openrex: driver registered!

lirc_openrex: using irq 299

lirc_openrex: auto-detected active low receiver on GPIO pin 43

Now we need to install packages which we help us with interfering with the receiver. During the configuration use "Simple IR diode (EXPERIMENTAL)" Custom as a receiver and "None" for transmitter:

apt-get install lirc liblircclient-dev

We can finally test the receiver. Run mode2 command and press any key on you remote controller. You will see a sequence starting like this:

# mode2 -d /dev/lirc0

space 4650628

pulse 9091

space 4441

pulse 629

space 503

Our infrared receiver is working. We can now assign a function to the particular keys. Run

irrecord -n -d /dev/lirc0 test_remote.conf

and follow the instructions. For demonstration we configured three color buttons. Now we can apply our settings and catch the pressed buttons:

rm /var/run/lirc/lircd.pid

lircd -d /dev/lirc0 test_remote.conf

irw

Here is output example:

0000000001fe30cf 00 red test_remote.conf

0000000001fe30cf 01 red test_remote.conf

0000000001feb04f 00 green test_remote.conf

0000000001fe708f 00 yellow test_remote.conf

0000000001feb04f 00 green test_remote.conf

0000000001feb04f 01 green test_remote.conf

0000000001feb04f 02 green test_remote.conf

0000000001feb04f 03 green test_remote.conf

From this point you can build you own application using remote control. :)

Read CPU Temperature

cat /sys/devices/virtual/thermal/thermal_zone0/temp

Read CPU Frequency

# cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq

396000

# cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq

996000

Read / Write MDIO (PHY Registers)

This application can read / write PHY registers. First, download & compile it:

mkdir tmp

cd tmp

git clone https://github.com/FEDEVEL/phytool.git

cd phytool

make

Example: Standard register read (simple read):

#read eth0 placed on PHY address 3 and register 2 (PHY Identifier, should be 0x0022)

root@ubuntu-imx6:~/tmp/phytool# ./phytool read eth0/3/2

0x0022

root@ubuntu-imx6:~/tmp/phytool#

Example: Vendor-Specific Register Read:

#reads: Eth0, PHY address 3, Device address 0x2, Register Address 0x06 (KSZ9031 RGMII TX Data Pad Skew)

./phytool write eth0/3/0x0D 0x02

./phytool write eth0/3/0x0E 0x06

./phytool write eth0/3/0x0D 0x4002

./phytool read eth0/3/0x0E

Example: Vendor-Specific Register Write:

#writes: Eth0, PHY address 3, Device address 0x2, Register Address 0x06 = 0x0 (KSZ9031 RGMII TX Data Pad Skew)

./phytool write eth0/3/0x0D 0x02

./phytool write eth0/3/0x0E 0x06

./phytool write eth0/3/0x0D 0x4002

./phytool write eth0/3/0x0E 0x0

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How to use & access OpenRex peripherals (Examples)

Content

DDR3 Memory test

Ethernet test

USB

SD

Preparing SD card for a filesystem

Listing SD card files in u-boot

HDMI

Booting from a SATA hard drive

Wifi PCIE mini card Intel 4965AGN

Audio SGTL5000

I2C

EEPROM

Wireless Modem (Telit HE910 PCIE mini)

PMIC regulator

Flashing LPC13xx microcontroller

Sensors

Temperature sensor

Humidity sensor

Gyroscope

Accelerometer & compass

IR Receiver

Read CPU Temperature

Read CPU Frequency

Read / Write MDIO (PHY Registers)

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