Setting the optimum channel for your WiFi using ubuntu

Setting the optimum channel for your WiFi using ubuntu

So today I finally decided to fix our WiFi troubles at home. We have a 100mbps internet connection from starhub with a Cisco DCP3925 router and although I can get a full 100mbps speed when connected by a LAN cable, on WiFi I barely got 10mbps on speedtest.net. I tried to call starhub for help but twice they made me change my WiFi channel to a random number and it didn’t work very well. I figured they were shooting in the dark with the channel numbers so I decided to do some research on my own and sort this out. Its really silly on part of starhub to use such trial and error methods to fix people’s WiFi. So here is the gist. Wifi works on 2.4GHz spectrum. The 2.4GHz spectrum is around 100MHz wide and it has 11 channels each 20MHz wide centered 5MHz apart from their neighbouring channels. Herein lies the muck. Each channels spreads itself over the center of next two channels on each side. While being on the same channel as another network is not ideal its better than being on a neighboring overlapping channel because 802.11 spec has methods for dealing with co-channel interference. This is bad because that means there is other wifi networks talking on some of the frequencies that your wifi uses.. So the ideal situation in your wifi setup is that there is no one talking two channels next to you. Enough of theory, now time for practical. How do you tell what are the channels being used in the area in your WiFi zone? In ubuntu you can use the iwlist command. sudo iwlist...

HTTPS/TLS on NginX and getting a certificate signed by a certificate authority

Today I decided to switch over my website to https mode and acquire a signed certificate for my website. I took the Comodo CA option and have gone for a free 30 day trial period. If things go smooth I might go ahead and purchase the certificate plan. I also learnt about three standardised different levels of validations plans from Cerificate Authorities i.e. Domain Validation : These types of certificate validations provide ssl encryption and certificate authority validates the ownership of the domain against the email address using whois record for the domain. This is the cheapest kind and the one I am using for this website at the moment. If you are committing financial transactions on your site its better to atleast get a OV certificate, which I explain next. Organisation Validation : These kind of certificate validations involve more extensive checks including in-person checks of your organisation’s details before a certificate is issued for your website. these are more secure. Extended Validation Certificates : These kind of certificates are issued after extremely intensive checks on your organisations. these are the most reliable certificates you can get. If your site uses this kind of certificate, it will get the elusive green bar in the address bar of your browser with your company name mentioned alongside. like all the bank websites get. Installing the certificate is quiet easy. First test that things work with ssl on your nginx server. First of all create directory to hold the key and certs: mkdir /etc/nginx/ssl create a key and unsigned certificate file for yourself: sudo openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout /etc/nginx/ssl/example.com.key...

Setting up ArchLINUX on BeagleBone Black – Part 3 – Setting up I2C and PWM controller

This Article is a placeholder for work in progress and I will log my success as I go forward. ArchLINUX has proven to be the lightest of all the distros that I have installed yet on Beaglebone Black. I have already got all the basics up and running and now I am setting up my perl stack and I2C and PWM interfaces. Make sure you have followed my previous instructions for ArchLINUX here. List of Instructions for Archlinux Install base devel and include all the sub packages. This is needed for installing XS modules and its roughly equivalent to build-essential package on Ubuntu $ pacman -S base-devel Install i2c-tools $ pacman -S i2c-tools Now we can go ahead and install Device::SMBus. This is the interface that I released to CPAN for connecting to I2C devices, in the last release Device::SMBus 1.05 I removed some dependencies on board and distribution specific differences in i2c-dev installations, so it works without issues on both Raspberry Pi and BeagleBone Black , ubuntu,armstrong and archlinux installations. $ cpan Device::SMBus I use the LSM303DLHC for my work with LSM303DLHC Altimeter and Magnetometer $ cpan Device::LSM303DLHC Installing module for using LPS331AP Altimeter Barometer $ cpan Device::LPS331AP Installing module for using L3GD20 Gyroscope $ cpan Device::L3GD20 My two ways of controlling PWM on Beagelbone Black: External I2C PWM Generator like PCA9685: I have already implemented this method before on Raspberry Pi, Since we have already setup I2C on ArchLINUX above, using PCA9685 is quiet simple, and while I have not lokked into the fact if the BeagleBone Black has a seperate microcontroller with a clock for controlling...

Setting up ArchLINUX on BeagleBone Black – Part 2

so I have been trying to get my usual environment up on archlinux.first comes vim $ pacman -Syq vim $ pacman -Syq perl-moose There is a cpan package for easily maintaining CPAN packages on arch linux CPANPLUS::Dist::Arch, its a CPANPLUS backend for ArchLINUXhttps://metacpan.org/pod/release/JUSTER/CPANPLUS-Dist-Arch-1.28/lib/CPANPLUS/Dist/Arch.pod $ cpan CPANPLUS::Dist::Arch setup cpan to use us automatically $ setupdistarch Install Device::SMBus as a pacman package $ cpanp -i...

Setting up ArchLINUX on BeagleBone Black – Part 1

Today I decided to give Archlinux a whirl with my BeagleBone Black board. Its a little more complicated to get it up and running compared to default suppported Angstrom distribution and generic GNU/LINUX distros, but it helps me save a lot of space. Instructions are listed on arch linux arm website at http://archlinuxarm.org/platforms/armv7/ti/beaglebone-black but I noticed that the download links go  down quiet often so you might have to try a couple of times to get the download complete. The Initial install occupies 28% of mmc storage compared to around 65% for angstrom, leaving lot of space for me to play around in! 🙂 As long as I can find a good wifi driver for the tiny usb wifi dongle I bought, I will stick to this distro for my UAV project. More on the adventures if things go as...