Author: Jason

Adjust the Duty Cycle of the 555 Timer without Changing the Frequency

Adjust the Duty Cycle of the 555 Timer without Changing the Frequency

This tutorial explains how to control the duty cycle of the 555 timer’s output. Not only does this design control the duty cycle but the frequency remains relatively stable during the adjustment. This is helpful for a number of applications such as working with pulse […]

Hiring a Proficient Bugsweep Team

Hiring a Proficient Bugsweep Team

Before we get started, you should know I am not pushing my own bug sweeping services. I do not sell my services commercially. I have 15 years of experience in technical surveillance countermeasures (TSCM) and am often called upon to give advice regarding many aspects […]

Wireshark VoIP Challenge: Protect the Flow

Wireshark VoIP Challenge: Protect the Flow

The objective of my career has been pretty simple up until recently. Bad guys want information X. Keep bad guys from taking information X. Simple enough. There’s also an Appendix to that objective. Bad guys always want to take information X. Build a program to stop […]

Wireshark VoIP Challenge

Wireshark VoIP Challenge

Knock off those network analysis cobwebs by downloading the file below and taking part in the Wireshark VoIP challenge. This a a short capture but a tricky one. Wireshark PCAP File MD5 Hash: 139b7dfea64ee097a4a415ba320cc5b6 The Challenge I’m currently putting together a new VoIP class and came […]

Clients React to the WiFi Pineapple

Clients React to the WiFi Pineapple

The WiFi Pineapple is a very evil rogue access point (AP) that can quite easily trick an unsuspecting WiFi enabled device or user into connecting to itself. It does this mainly through a suite of programs called PineAP. Thanks to the makers of the WiFi […]

How to Use a 555 Timer in Monostable Mode

How to Use a 555 Timer in Monostable Mode

It’s been about a year since my last tutorial. Over the last year I learned that teaching in the real world will take away time from teaching in the virtual world. Many people have contacted me asking about a tutorial for the 555 timer in Monostable […]

Anatomy of a Malicious GPS Tracker

Anatomy of a Malicious GPS Tracker

This is the kind of stuff I love. Recently I was given a GPS tracker from an individual. This tracker had been embedded in a victim’s car for 6 years. The following video examines the tracker’s components and method of install. Below the video you’ll […]

Math of the 555 Timer

Math of the 555 Timer

If you’ve been following along with the 555 timer series, this video describes how to derive the formula that describes the timing of the circuit. Starting with just 2 components, we’ll work our way to an answer.

How to Control the Duty Cycle of a 555 Timer

How to Control the Duty Cycle of a 555 Timer

Continuing with a focus on the 555 timer, this video tutorial looks at how to vary the pulse width of a 555 timer’s output. It’s all possible with just a a hand full components. By varying the duty cycle one may vary the blink rate on an […]

Cascading 555 Timers for Custom Blinking LEDs

Cascading 555 Timers for Custom Blinking LEDs

For the past several weeks we’ve looked at blinky LEDs, 555 timers, and resistors. This week it’s time to put it all together into an application. A YouTube subscriber suggested the project as follows: How would you go about having an led blink twice, then […]