Dual Power Supply [Gallery]

In first year of engineering, we were taught about rectification of ac signal by diode and how to make a simple power supply using step-down transformer for decreasing the voltage level of mains, diode for rectification, capcitors for filtering and voltage regulators at the end to regulate the voltage to some proper level.

Until I write a proper post for the Power Supply project,  here is a gallery of the project; enjoy..!

Tachtastic – AVR Tachometer

Tachtastic - an Image from the old days..

“Tachtastic”, a not so creative name for a tachometer. I was in my 2nd year of BE at the time and making a Tachometer seemed like a good idea and an easy project (according to a senior).

For those who don’t know, a tachometer is a device which can count the number of revolutions/rotations of something by use of some sensing mechanism. The sensing mechanism may or may not touch the device whose rotation is being measured. [Here is the Wikipedia Page for Tachometer]

I wanted to make a portable Tachometer which could run on a 9V battery and be small enough to fit in a pocket, yet be versatile to support multiple types of sensors and other basic functionality found in consumer tachometers.

Tachtastic – AVR Based Tachometer [Image Gallery]

Continue reading Tachtastic – AVR Tachometer

Selection Menu for Text LCD [AVR]


An option-selectable-menu on a text LCD using an AVR is not such a big deal, but having it sure saves a lot of time as such a menu can be quite helpful and useful in many projects. Here’s a video of the simulation:

I first made the menu for my AVR Tacho-meter project (AVR Tachometer [Gallery]) that I named Tachtastic…. The menu serves basic functionality like dynamic options (not to be changed on run-time), simple item selection via external input (next/prev button and select/back button), easyily implementable sub-menus (treated as separate menus which show up on a specific menu item selection)

I used the LCD library of Peter Fluery, the hardware in the project attached uses LCD with 2 lines so some changes will be needed if you have 2+line LCD, there are 4 external push-to-make buttons for prev/next and select/back.

The code is well-commented and self-explanatory, so I won’t be putting that up here, the project uses my template.h file (included in the download), the code might seem hard-wired at some places but easily modified. I have already used the same code with small changes in a other projects. So, I am putting all the stuff here, maybe someone will benefit or tell me how I can improve.

Software Used:

  • AVR Studio with WINAVR (AVR GCC)
  • Proteus for Simulation
  • LCD Interface Library from Peter Fleury (http://www.jump.to/fleury)
[Download not found]

L297-L298 Stepper Driver – Vero-Board [Gallery]

Another day, a cricket match which the whole nation is watching and I just finished making a circuit, on vero-board.

L297 and L298 make a perfect pair for a stepper motor driver circuit, like the two were made for each other (actually they really are made as a pair, I think…).

As usual, I wanted to make it work, look nice and be compact at the same time, the final result says that I somehow reached my goal, the motors are working, the circuit is small and looks just cool enough.

I will put up some explanation for the circuit when I get time someday, until then, check these links for some explanation: L297+L298