Thus spake vu2swx

Ubuntu 16.04 Booting to text mode

I was trying to boot a newly installed Ubuntu box into text mode.   The usual methods failed and  after googling  a little  I figured out that  Ubuntu  16,04 uses systemd  for controlling startup services.   The solution for the problem is

 

sudo systemctl enable multi-user.target
sudo systemctl set-default multi-user.target

Mapping between runlevels and systemd targets

Run Level Target
0 poweroff.target
1 rescue.target
2,3,4 multi-user.target
5 graphical.target
6 reboot.target

If you just want to change runlevel only

sudo systemctl isolate multi-user.target
 

Disabling touch pad while typing:- Ubuntu 14.04

Currently, I am using an Asus X200M netbook with ubuntu 14.04 lts. The keyboard of the netbook is slighly small compared to regular laptop. This is  a slight drawback of all netbooks.  For me it took only a couple of hours to get adjusted to the new keyboard.

However, while typing, my thumb inadertently touches the  touch pad and the cursor jumps to some random location.  I am always using an external mouse for navigation  as  I dont like to use t touch pad . So I decided to find out a way to disable the touch pad when I am typing long documents.

Here are the steps for disabling and  enabling  touch pad.

Find out the device id of your touch pad.   Open a terminal and type

$  xinput list

output from xinput

Look for the id of your touch pad. In my case the touch pad is detected as a logitec mouse and the id is 13.  The other mouse shown in the figure is my external mouse. If in doubt, remove the external mouse and re run the command to find out the correct device id.

In order to disable touch pad type the following command.

$ xinput set-prop 13 "Device Enabled" 0

You can eneable the touch pad by changing 0 to 1 in the command above.

Installing latest arduino on Ubuntu 14.04

I have been   tinkering with NodeMCU devkit boards recently. The easiest way to program these little beasts is to use arduino platform and install the compilers and other tools from . Unfortunately the stock arduino shipped with ubuntu 14.04 is quite old.  You need a recent version of arduino  software. to get the esp8266 board working.

Here is what I did.

Removed the existing arduio installation

My nodeMCU collection.
My nodeMCU collection.

$ sudo apt-get remove arduino

Download the appropriate arduino software from arduino.cc.  This is available for both 32 bit and 64 bit editions.  Choose the correct version.

The arduino software platfrom is written  in Java. So install java runtime.

$  sudo apt-get install openjdk-7-jre

Unzip the arduino software  and move it to an appropriate location. I moved it to  /opt.

tar -xJf arduino-1.6.4-linux64.tar.xz
sudo mv arduino-1.6.4 /opt

Add appropriate path to .bashrc file.

I added PATH=$PATH;/opt/arduino-1.6.4/bin. Change it according to your arduino location and version.

Open a terminal and execute the new arduino.