Fsm morse code

Thread Starter

Rave

Joined Nov 9, 2010
1
Hello,

I have a question, well the question is the question it self, i don't understand what they are asking for.

Question::
"In this part of the exercise you are to implement a Morse code encoder using an FSM. The Morse code uses
patterns of short and long pulses to represent a message. Each letter is represented as a sequence of dots (a short
pulse), and dashes (a long pulse). For example, the first eight letters of the alphabet have the following representation:
A . —
B — . . .
C — . — .
D — . .
E .
F . . — .
G — — .
H . . . .
Design and implement a Morse code encoder circuit using an FSM. Your circuit should take as input one of the first
eight letters of the alphabet and display the Morse code for it on a red LED. Use switches SW2-0 and pushbuttons
KEY1-0 as inputs. When a user presses KEY1, the circuit should display the Morse code for a letter specified by
SW2-0 (000 for A, 001 for B, etc.), using 0.5-second pulses to represent dots, and 1.5-second pulses to represent
dashes. Pushbutton KEY0 should function as an asynchronous reset."

are they asking me to the input (assuming S0,S1,S2) will be used to put in letters from A-H, then am i to display the pulses on the red led by having it flash, example for H it would blink for times, and for G, it would be on for 2* (1.5 seconds) then blink once. also they ask me to display the moorse code, it it just the red LED or do they wan't me to print A-H on the 7seg display.

i am unsure whats being asked. can anyone shed any light on it, thank you.
 

eblc1388

Joined Nov 28, 2008
1,542
You don't need to display the character selected on a 7seg LED.

Beware there should also be a time gap, length equal to the time of "dot", between dot/dash.

This is what you are required to design.

 

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MMcLaren

Joined Feb 14, 2010
842
May I ask what is an FSM, please?

As far as Morse code timing, here's is what I use in my programs;

Rich (BB code):
;
; Some general information about Morse Code Speed;
;
; <1> A Dash is three times longer than a Dot
; <2> A Dot space between Dashes and Dots within a character
; <3> A pause between characters is three Dots long
; <4> A pause between words is seven dots long
;
; The word 'Paris' was established as an international standard
; for calculating the speed of Morse in words-per-minute (wpm) 
; and characters-per-minute (cpm)...  This works out to 50 dots
; (or dot times) per word and yields the following timing;
;
;  5-wpm ( 25-cpm) =  60 /  250 dots = 240-msec / dot
;  6-wpm ( 30-cpm) =  60 /  300 dots = 200-msec / dot
;  7-wpm ( 35-cpm) =  60 /  350 dots = 171-msec / dot
;  8-wpm ( 40-cpm) =  60 /  400 dots = 150-msec / dot
;  9-wpm ( 45-cpm) =  60 /  450 dots = 133-msec / dot
; 10-wpm ( 50-cpm) =  60 /  500 dots = 120-msec / dot
; 15-wpm ( 75-cpm) =  60 /  750 dots =  80-msec / dot
; 20-wpm (100-cpm) =  60 / 1000 dots =  60-msec / dot
; 25-wpm (125-cpm) =  60 / 1250 dots =  48-msec / dot
; 30-wpm (150-cpm) =  60 / 1500 dots =  40-msec / dot
; 35-wpm (175-cpm) =  60 / 1750 dots =  34-msec / dot
; 40-wpm (200-cpm) =  60 / 2000 dots =  30-msec / dot
; 50-wpm (250-cpm) =  60 / 2500 dots =  24-msec / dot
;
 

MMcLaren

Joined Feb 14, 2010
842
Is the OP using a microcontroller? I've got a few microcontroller based Morse players. I wonder which part of the program would be implemented as a "state machine" though?

Cheerful regards, Mike
 
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