TT’s Jottings-Blog of VU2SWX

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.

$ 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.

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

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.

I took a session on recycling old PCs with LTSP at   barcamp kerala 7 last Sunday.  Even though I am associated  with the organizers of barcamp ever since its inception in Kerala, I could not attend any of the previous ones due to various reasons. So I was a bit skeptical about the kind of people I may meet. Also, this was the first public lecture I gave after assuming charges of Principal College of Engineering Attingal. I  conveniently hid this fact from the audience suspecting that my job profile might overshadow the geek in me.

I was picked up from home by Kenney Jacob at 5.30 am  and we stated our journey to Changannasery on a TATA VISTA . The car was fantastic with GPS can other gizmos . A few of Kenney’s colleagues were also present in the car. We reached the  venue around 8.45 to find that the  gates of the Krishtu Jayanti college were closed. Kenny made some frantic telephone calls and finally we were asked to enter the college via  the  gates of a Catholic church.

There were around  70 guys in the hall. There was some initial hiccups and the  sessions took some time to start . I missed introductory remark by Kevin as I went to the nearest tea shop for a quick dose of coffee. The next session from Prassed Pai on 3d graphics programming was good and reminded me of my PG classes at CUSAT where we did all the shading and drawing algorithms. I think most of the audience was clue less about the topic.
The next session    Building Complex Website the Drupal Way from  Fredrik Jonsson? was   enlightening.
The third  session on Media by Kenney Jacob initiated some interesting discussions among the audience. Some of the participants expressed the fears about corporate media  manipulating facts .
Next was a cake cutting session . Some one suggested Fredrik Jonsson’s name for the event and every one clapped  when he cut the big cake sponsored by   ayruz web holdings  . Later I had lunch at a local teashop .
I took the first session in the after noon. My Idea was to set up my laptop as ltsp server and net book as the client . Then project the client to  the  big screen and start the presentation on the client.
The Sharp projector  at the venue was behaving erratically. It showed only half of the screen. I had to change instantly to the white board and start writing.  I briefly explained the  LTSP  with a figure that I drew and later on moved the projector to my laptop. The presentation was shown after explaining things with a white board.  I think half of the audience got confused by then.
The next session from UST global was  quite boring. I think such PR crap should be avoided in barcamps. I missed the session by Binny VA as I went out for a tea again.

The last session on linux devices was good,  but Praseed Pai  seemed to be the only person understanding it.
Finally, Fr. Abraham Mulamootil made a surprise appearance. I think it is the first time a catholic priest is seen publicly in a bar(camp). Any way he seems to be the only geek in the church.
The entire event was wound up around 6pm.
The facilities at the venue were pathetic.  No one from the college turned up. There was no net connectivity.  The wifi link of the college was running but their firewall was preventing outgoing net  request. Hope the next barcamp at Thiruvalla will be better and more interesting.

I am using pidgin as  chat client for both yahoo and gtalk. Recently, yahoo has stopped support for older versions of their own yahoo messenger clients. ( anything less than version 7.5  fails ) . It also means that most of the third party clients such as pidgin has  problems  in login.

On my ubuntu 9.04, the default  pidgin version is  2.5.5.   You can work around the yahoo login problem  as shown below.

Open Accounts-> Manage accounts.

Click on the account you want to  fix

Click on modify.

Click on advanced tab.

The pager server is set to  scs.msg.yahoo.com

Change it to    cs101.msg.mud.yahoo.com

Click on Save

Restart  pidgin

It seems yahoo is  rolling out a new authentication protocol. Let us wait for  a new pidgin  update

Update:

Pidgin 2.5.7 which fixes the yahoo login problem is out. You can install it as given below.

Import the  public key  for Launchpad PPA for Pidgin Developers

$ sudo apt-key adv –recv-keys –keyserver keyserver.ubuntu.com \     67265eb522bdd6b1c69e66ed7fb8bee0a1f196a8

Add the following lines to /etc/apt/sources.list

deb http://ppa.launchpad.net/pidgin-developers/ppa/ubuntu   jaunty main

Run apt-get update and apt-get install pidgin.

The PPA contains new pidgin releases for other versions of ubuntu (  dapper gutsy, hardy ,intrepid and karmic) You can just replace jaunty in sources.list line indicating this ppa with you distro and enjoy yahoo messenger on pidgin.

Scribefire  is a cool firefox add on which a  blogger cannot miss   Using this  firefox add-on, you can blog with out leaving your browser.   Installation is simple. Browse to this page Just click on the addto firefox button and restart firefox.

You can start scribefire  by clicking on the scribefire icon. It will open up scribefire as shown below.

Now, you can set up a blog account from the blogs menu and start enjoying scribefire. It supports several features such as notifying various blog aggregations services , ftp uploads etc. Have a look at the features.

Scribefire startup screen