Ubuntu 16.04 Booting to text mode

December 8th, 2016 Comments off

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
 
Categories: Computers Tags:

My talk at BarCamp July 2015

June 17th, 2016 Comments off

Here is my talk at BarCamp 2015. The talk is in my mother tounge,Malayalam.

Categories: Computers Tags:

Disabling touch pad while typing:- Ubuntu 14.04

April 9th, 2016 Comments off

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.

Categories: Computers Tags:

Installing latest arduino on Ubuntu 14.04

April 9th, 2016 Comments off

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.

Categories: Computers, Gnu/Linux, Micro controllers Tags:

Wireless on Asus X200M netbooks: Ubuntu 14.04 LTS

April 4th, 2016 Comments off

We resently bought several Asus X200 series netbooks for our faculty members. The main attraction of this  cute  netbook is its  light weight and a built in HDMI port. We plan to use them extensively for   content delivery in class rooms. These  machines are really cheap, costing around Rs17000 ( around $260).  The base model comes with Intel® Celeron® Dual-Core ~ 2.58 GHz Processor and 2GB ram, DOS operating system. It has an 11.6 inch LED display.

Our idea was to put   ubuntu 14.04 and deploy the machines. The machine has an ethernet port and wifi port.  Installation of Ubuntu 15.10 was a smooth affair.  Unfortunately, the broadcom wifi interface did  not work out of the box. Here is what I did to fix the issue.

  1. Find out which wifi chip is used.

$lspci broadcom wifi lspci

The wifi chip is  Broadcom Corporation BCM43142. You have to download and compile the kernel module for this chip.

2) Make sure that the machine is connected to internet and the apt sources are properly set up

3) Update  the machine

$ sudo apt-get update

4) Finally instal the  bcmwl driver.

$ sudo apt-get install linux-headers-`uname -r` dkms build-essential bcmwl-kernel-source

This will downlad necessary driver  your wifi will be up and running. The above line installs dynamic kernel module support  and compiles the broadcom wireless driver.

Categories: Computers, Gnu/Linux Tags: