Posts Tagged ‘Logic7400 Contest’

7400 Contest !

Sunday, December 2nd, 2012

The 7400 Contest had loads of awesome entries !

My entries Tic Tac Toe won a first place and Mathemagic won a third place !

Thanks a lot to dangerous prototypes for running the contest !

Now for the prizes !!!

Unfortunately, will be busy for the next two months :( – All experiments on hold !!!!!!

Edit : Here are some pictures!

1. Components form

2. Analog Discovery from Digilent!!




Sunday, October 28th, 2012

First of all thanks to DangerousPrototypes! its because of you guys I worked on logic gates after college – else its usually the usual microelectronic stuff! :)

This build is a simple ‘Tic Tac Toe’ game. I ended up using 30 Logic ICs ! :)

Lets see the video first, then lets see the design



Design document:

<PDF alert> This document: Tic_Tac_Toe has all the block diagrams and circuit diagram used.



In the middle of the build

Tic Tac Toe

Tic Tac Toe


Do leave a comment if you have any queries!

PS:Β  The casing is ugly πŸ˜› Trying to build a good case for this project!

<Edit> Won a first place in the 7400 contest !


Mathemagic – Mind Reader

Thursday, October 25th, 2012

This is a simple application where in you think of a number from 1-99 in your mind and then the machine tells you what it is !

All you have to do is, think of a number and say if it is greyed out in the series of cards shown.

Before we step into any detail, Watch the video :)



The concept behind this is a BCD to 7-Segment decoder(IC7447). The unit and tens place of the number are in BCD. For example let’s consider the number 24

Number 2 4 – This in BCD would be 0010 0100. Thus this number would be found in sheet3 and sheet6. When you press these corresponding switches, the number would come up in the 7-segment display.

The switches used here are momentary push switches. When the switches are pressed, we would need it to be giving a constant HIGH. For this we use D Flip Flop (IC4013).


Switch Configuration:

The flip flop is used to sense the switch input and it goes high permanently (until the reset button is pressed). For this we connect the β€˜data’ pin to VCC and the clock pin to the switch output. As the flip flop is positive edge triggered, this pin is pulled low with a resister and the switch is connected to VCC. When the switch is pressed, the pin is pulled up to VCC and this triggers the flip flop, thus the output pin β€˜Q’ goes HIGH.


IC7447 is used to drive the 7Segment. This circuit uses a common anode 7-Segment, the output of flip flops are directly fed to the BCD inputs of the 7segment driver.

Circuit Diagram:

<Very large PNG alert | Click to open in new window>


Let me know your comments :)