Design a Decoder using Logic Gates to display letters on a 7-Segment Display

Question

The task I got is to design a similar circuit to a standard BCD to 7-Segment decoder, except only using Logic Gates and to display a eight letter character word, for example: SHELFLES

As I have forgotten all by now as it comes to digital logic, k' maps and etc.

I would appreciate points and tips for a direction to how I should go about doing this.

Thanks in advance!

Answer 1

Start from truth table. You have 26 alphabets so 26 input combinations(respective asci values). And in the output side 7 leds.

For example to display A (0110 0101)

enter image description here

from this picture you can conclude that when input is 0110 0101 then LEDs A,B, G, F, E, C must glow and LEDs D must be OFF.

Similarly find LED condition for all 26 combinations.

Draw K map for each LED, by that you will get 7 Boolean equations. If you implement these you will get the circuit.

Hope this will help you. If you need any clarification in any step let me know.