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Showing posts from June, 2007

How to setup 2FA On Linux SSH Login

  This is a simple setup guide to enabling Two Factor Authentication (2FA) on Linux SSH login. I this article I wont go deep into setup and issues that I have faced when implementing this. First thing is first Update your system first. I have used Ubuntu 20.04 and it is always up to date. To enable 2FA you need to install google authenticator modules sudo apt install libpam-google-authenticator Configuration for PAM and SSHD Add the the following line to /etc/pam.d/sshd and After adding this line please restart the sshd services.  auth required pam_google_authenticator.so Go to /etc/ssh/sshd_config and check if the following line exist. Default value will be "no" so change it to "yes" to activate.  ChallengeResponseAuthentication yes Configuration for Authenticator In the terminal run google authenticator command It will ask few things to acknowledge by user. Details you can see from the below video. Once this part is done you are ready to use the 2FA in ubuntu. T

PCB Development Chem Test

Last night i did some test with the chemicals which is used to develop PCB. For test i used piece of copper plated PCB sheet around 2 inch, and drew a simple circuit from a water proof pen and this circuit will detect infrared signal. For that i used a surface mount(SMD) LM358. I used surface mount chip because i want to make the circuits compact than now. Even though i used a SMD chip i used normal 1/4 watt resistors in my circuit cause this time i did not order for the SMD resistors and stuffs. This was just a test for the chemicals that i have so the test is perfect. Chemicals are good to go for other developments. In my robo, the circuits will be surface mount ones. This week i will do some positives to burn from chemical. Then it will look like an original circuit.

Season Break

After break i am back with the blog. Now i am designing a circuit which will be used in my robo. This will take quite long time for experiments and to implement. At last i decide to start it and i will update you guys very soon. ;)

A Keypad with a brain

As you all know in my previous post i have talked about an keypad which was designing. Finally almost the hard part is over. This keypad or controller based on three to four parts. First is keypad part: Its 16 key keypad which i have design and implemented. Its 16 push buttons connected to the input shift register. When the user operates a button, the shifts will change it to serial format and fed to micro controller. Second part is input shift register: It handles all the button activities. which means it will convert the button input to serial format. Actually the shits are parallel to serial or a MUX. Third part is the brain: Brain of the this circuit does all the computing. The code that me and my friend whoknowz wrote was doing the conversion part to determine which button was pressed. Its kinda "AI" part. It was hard at first but later was easy to decode the whole serial part. The brain stores the password of this system and when the user insert the pass it will display

Input Shift Register mod

This is an updated version of the previous circuit. This one is actually a keypad. Soon i will code for storing password and tadaa it will be come 4x4 numeric keypad with other functions.

Input Shift Registers

This small key pad like circuit with an input shift register (74HC597) is a test circuit for input shift register. The shift register is parallel in and serial out register. The serial part is handle by the micro controller. For this test my friend wh0kn0wz was helping with bug in micro controller code. Thanks to him for identifying it. :P This shift register can be used in key pads and other multiple controllers.

BuzzzzzzzzzzzzZ

I am back after days spent away from blog. I was very busy with office works so i did not spend any time with my electronics stuffs. I am sure very soon i will pub a new experiment of mine. always give a peep to this blog..;)