Skip to main content

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

Propeller Clock...cont

I almost spend two days on this experiment and just found that the new concept in this experiment works well. But the problem comes when we think of current. The current that i get is two low to power on electronics.

The moving transformer concept is cool one to experiment. ;) (this message is for electronics dudes out there). I wound coil on the moving part(150 Turns) of the fan and wound another coil that will be fixed around the moving part(200 Turns). Then i gave PWM signal to the GATE of FET which is connected to the fixed coil, at the frequency of 20KHz.

I used FET because it is capable of high speed switching then transistors. Finally i got an AC voltage across the the moving coil(7.8 V) and then i connected an LED just to check the performance. Actually the concept works (Transfer voltage to an moving coil). Bad part is the current is too low and if i want to increase the current i need to wound think gage coil and this will become expensive for this kinda small projects. If you want to use this method for a big project, its ok to use..

I took some pictures of the experiments and you viewers have a look at it. For the propeller clock i will just skip this for some time and will do when i get an motor that can be tap out an a wire from the comunitator. This idea will be better for a propeller clock. So everyone enjoy pics..


















The moving part(Coil wound up to 150 Turns)





















The fixed coil(200 Turns)






















Fully assembled with a test LED



















Test successful. See more pictures from flickr

Comments

Anonymous said…
This is a very useful thing you did, as I am building a propeller clock, and I need to wound the wires as well. Also i think you could use a thinner wire on the part with led, and thicker wire on the other part(stationery one)

Popular posts from this blog

SIMCOM SIM900A fixed

Since everyone is interested in this post and lots of request comes to get the firmware, i have put a link so that everyone can download it easily. SIMCOM 900A firmware Its been a while that i was trying to fix the SIM900A GSM module. This module support local GSM band but after some researches it was concluded that it is carrier locked :(. After long conversion of days to actual chip manufacture SIMCOM, they told it can be fixed by updating its firmware to latest original version but unfortunately they don't provide firmware to small parties. I never stop trying to get the firmware and SIMCOM again replied, this time they said contact local SIMCOM supplier and request for firmware. But this little Maldives don't have SIMCOM or any electronics manufacturer. So i contacted my friend coody from NOA LABS/Smart prototyping (a friend in china) and told him to help me. I explained him what to do so he can communicate with SIMCOM in china. Finally he sends and email saying that

Clover Display M302 hack

Its been a while i have this LCD and today i thought of connecting the LCD display to Arduino. Unfortunately i could not found any pin outs of this from any where and from the manufacture. Actually this is very old model which i got from old FAX machine and this display is a very cheap from online sources. Clover Display M302 PCB Ver 1.0 (16x2) which has 10 pin flat cable. After researching for a while from the internet i have seen in many forums people are asking for help on how to connect it and what is the pin configurations? so i thought of helping them as well as my self at the same time. After going through some of my old collections of Russian data of displays and things i found a basic diagram of how 10 pin LCD display configuration.  PIN1   - VSS PIN2   - VDD PIN3   - CONTRAST PIN4   - RS PIN5   - R/W PIN6   - ENABLE PIN7   - DB4 PIN8   - DB5 PIN9   - DB6 PIN10 - DB7 I tried these configurations and wired up to the arduino with the LCD sketch

ESP8266 + DS18B20 Temperature sensor sends data to Thingspeak.com

Its been a while i was searching for a cheap wifi module and with the help of smart-prototyping.com , i was able to get a module almost less than USD 5. To connect the module to breadboard for prototyping, i made a small jig to interconnect with the board easily. So i can wire up the device and interface anything to GPIO's. Be careful with the module cause the device it powered with 3.3V and both UART side levels will be 3.3V so i recommend to use a FTDI converter with 3.3V level select.(one i used can select 3.3 and 5 volts) if you connect 5V the module will fry up. If you have 5V or 12V supply to power up the module i suggest to use LD1117V33 to make 3.3V. The stock Firmware in the ESP8266 supports AT commands and for communicating with this need an micro-controller like Arduino. But i want to make a simple solution for that without using external micro-controller. NodeMCU firmware was the best thing i found. To upload the NodeMCU firmware please do a google sear