Persistent names for usb-serial devices

Veröffentlicht am 23. Januar 2015 von Julian Tatsch

Many usb-serial devices appear as /dev/ttyUSBX or /dev/ttyACMX in the system, the link changing every time several of these devices are plugged in. This is unsatisfying if you want to access these devices from a script. One solution is to use a UDEV ruleset to make a symbolic link for each device. Here is how to do it.

Determine vendor and product id of the usb-serial device:

lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 004: ID &lt;strong&gt;0403:6001&lt;/strong&gt; Future Technology Devices International, Ltd FT232 USB-Serial (UART) IC
Bus 002 Device 003: ID 0bda:0724 Realtek Semiconductor Corp. 
Bus 002 Device 002: ID 05e3:0608 Genesys Logic, Inc. USB-2.0 4-Port HUB
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

lsusb

Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Bus 002 Device 004: ID <strong>0403:6001</strong> Future Technology Devices International, Ltd FT232 USB-Serial (UART) IC

Bus 002 Device 003: ID 0bda:0724 Realtek Semiconductor Corp.

Bus 002 Device 002: ID 05e3:0608 Genesys Logic, Inc. USB-2.0 4-Port HUB

Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Determine serial number of the device:

udevadm info -a -n /dev/ttyUSB0 | grep '{serial}' | head -n1
ATTRS{serial}==&quot;&lt;strong&gt;DAE0011W&lt;/strong&gt;&quot;

1 2	udevadm info -a -n /dev/ttyUSB0 \| grep '{serial}' \| head -n1 ATTRS{serial}=="<strong>DAE0011W</strong>"

Create a UDEV ruleset that makes a symbolic link for each device:

sudo nano /etc/udev/rules.d/99-usb-serial.rules

and add and adapt to your needs:

SUBSYSTEM=="tty", ATTRS{idVendor}=="0403", ATTRS{idProduct}=="6001", ATTRS{serial}=="DAE0011W", SYMLINK+="1wire"

after replugging the device, there will be a symbolic link ‚1wire‘ be created for your device.

Lautsprecher in Fhem einbinden

Veröffentlicht am 4. Januar 2015 von Julian Tatsch

Antworten

Hier ein kleines Tutorial wie ein Lautsprecher an einem Radaa Rock oder Raspberrypi in fhem eingebunden werden kann. Zuerst die alsa und Utilities installieren:

sudo apt-get update &amp;&amp; sudo apt-get install alsa-base alsa-utils

1	sudo apt-get update && sudo apt-get install alsa-base alsa-utils

In der fhem.cfg einen Lautsprecherdummy und ein Notify darauf anlegen:

define Lautsprecher dummy
define playbackNotify notify Lautsprecher:* {\
    playSound($EVENT);;\
}

define Lautsprecher dummy

define playbackNotify notify Lautsprecher:* {\

playSound($EVENT);;\

}

In der 99_myUtils.pm eine entsprechende Funktion anlegen:

sub
playSound($)
{
    my ($file) = @_;
    system(&quot;aplay media/&quot;.$file); 
}

sub

playSound($)

{

my ($file) = @_;

system("aplay media/".$file);

}

Im fhem root ein Verzeichnis „media“ erstellen, gewünschte Wave Dateien einfügen und fhem zuordnen:

mkdir media
sudo chown -R fhem media

1 2	mkdir media sudo chown -R fhem media

Eine Wave-Datei kann nun folgendermaßen abgespielt werden:

set Lautsprecher alarm.wav

1	set Lautsprecher alarm.wav

Automatically update linux systems

Veröffentlicht am 16. August 2014 von Julian Tatsch

Antworten

Keeping your computer systems up to date has always been important. But now that word has gotten out that big brother is scanning whole countries networks and actively probes their ports keeping systems up to date is the least should do. Who knows if they are not installing backdoors as well, as a precautionary measure of course 🙂 So at least make it harder for them by keeping your system patched, it can be as easy as installing and running unattended-upgrade:

sudo apt-get install unattended-upgrades -y
sudo unattended-upgrade

1 2	sudo apt-get install unattended-upgrades -y sudo unattended-upgrade

Now edit /etc/apt/apt.conf.d/10periodic:

sudo nano /etc/apt/apt.conf.d/10periodic

1	sudo nano /etc/apt/apt.conf.d/10periodic

and add/edit the following lines:

APT::Periodic::Update-Package-Lists "1"; APT::Periodic::Download-Upgradeable-Packages "1"; APT::Periodic::Unattended-Upgrade "1";

Now you can select which updates to run by uncommenting some lines in /etc/apt/apt.conf.d/50unattended-upgrades:

sudo nano /etc/apt/apt.conf.d/50unattended-upgrades

1	sudo nano /etc/apt/apt.conf.d/50unattended-upgrades

I usually allow security and normal updates but reject proposed and backports.

SSH Access with certificates

Veröffentlicht am 1. August 2014 von Julian Tatsch

Antworten

To easily access all your computers you may want to authenticate yourself with certificates.

On a Mac, first install the missing ssh-copy-id:

brew install ssh-copy-id

1	brew install ssh-copy-id

Then you can copy your public key to the ssh hosts you frequently need by:

ssh-copy-id -i ~/.ssh/id_rsa.pub username@hostname

1	ssh-copy-id -i ~/.ssh/id_rsa.pub username@hostname

You may get this warning if the host already is in known hosts:
Warning: the RSA host key for 'panda' differs from the key for the IP address '10.152.196.248' Offending key for IP in /Users/tatsch/.ssh/known_hosts:19 Matching host key in /Users/tatsch/.ssh/known_hosts:24 Are you sure you want to continue connecting (yes/no)? yes

If that happens, simply delete the offending lines by

sudo nano /Users/username/.ssh/known_hosts

1	sudo nano /Users/username/.ssh/known_hosts

and ctrl + K to delete the whole line

UART on Pandaboard

Veröffentlicht am 27. Mai 2014 von Julian Tatsch

Antworten

List your users group with:

groups ${USER}

1	groups ${USER}

Add the user to the dialout group if necessary, to fix permission issues:

sudo adduser phoenix dialout

1	sudo adduser phoenix dialout

Now you can access all your uart devices:

ls /dev/tty*

1	ls /dev/tty*

for example UART4 on expansion connector A:

miniterm.py /dev/ttyO3

1	miniterm.py /dev/ttyO3

I2C on Pandaboard

Veröffentlicht am 24. Mai 2014 von Julian Tatsch

Antworten

sudo apt-get install i2c-tools
sudo modprobe i2c-dev
sudo i2cdetect -y -r 1

sudo apt-get install i2c-tools

sudo modprobe i2c-dev

sudo i2cdetect -y -r 1

To load the kernel module automatically at boot:

sudo nano /etc/modules

1	sudo nano /etc/modules

add i2c-dev

Finally add your user to the i2c group to fix permission problems:

sudo adduser phoenix i2c

1	sudo adduser phoenix i2c

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Archiv der Kategorie: Pandaboard

Persistent names for usb-serial devices

Lautsprecher in Fhem einbinden

Automatically update linux systems

SSH Access with certificates

UART on Pandaboard

I2C on Pandaboard