There are many types of emergency vehicle lights that installed on police cars, fire engines, ambulances, etc. This post presents circuit for blinking alternately the two red LEDs and two...
This post presents circuit of electronic coin toss also known as coin flip circuit or heads or tails circuit. When the push-button is pressed, the LEDs will start blinking fast...
We can send ICMP requests to another host to test whether host is reachable. However, ICMP requests can be blocked by firewalls. The arping is a command line tool that...
The wavemon is a command line tool that allows to monitor a wireless network devices. This tool enables to view wireless signal strength and noise levels, packet statistics, information related...
When working with high voltage circuits is useful to have a non-contact voltage detector also known as tester which enables to detect the presence of voltage without direct contact. This...
This post presents circuit which produces a long up and down variation of the sound that similar to police siren. Circuit is based on two 555 timers which operates in...
Vim is a text editor that allows to create and modify text files via command line. Vim is an improved version of the old Unix Vi text editor. Vim provides...
The ncdu is a command line tool that enables to view and analyze disk space usage. This tool shows the disk space used by individual directories.
By default, ncdu is...
This post presents circuit which detects darkness using light dependent resistor (LDR) and produces a beep alarm by piezo buzzer. Circuit is based on 555 timer in astable mode to...
This post presents circuit for blinking two LEDs alternatively using two BC547 transistors. This circuit is commonly called a flip flop LED flasher. Generally used in alarm systems to produce...