Please give some hint.. Do i need to focus only in 74ls90?? nothing more? the changes are only in 74ls90?
The decoder is not connected correctly, and neither is the display. Start by answering all of the questions I asked in my earlier post.Please give some hint.. Do i need to focus only in 74ls90?? nothing more? the changes are only in 74ls90?
Yes, as stated in the datasheet. This counter will count in BCD mode and in bi-quinary, which will give a divide by 10 square wave (which isn't what you want).so CKB must really connect at A...
no... its from me.. i just copied the normal 7-segment that count 0-9. And yes, I was planning to modify it through this one so it would only count to 8 and then clear to zero..Did you design the circuit you posted or was it given to you by your professor? If he gave it to you, was the instruction given to modify it so it would only count to 8 and then clear to zero?
Have you read the datasheet?
Ha! You make me laugh so hard. This is a dream of yours? I've never heard of anyone talking about their dream while they are still sleeping!not yet... O.O
Thats what i currently doing!~Ha! You make me laugh so hard. This is a dream of yours? I've never heard of anyone talking about their dream while they are still sleeping!
Read the datasheet immediately!
Does this give you any ideas how to reset the counter to zero?
View attachment 100080
That's the only counter chip in the circuit...What is the counter doing as wired?
- what counter? the 74ls90?
Why did you leave one of the R0 inputs floating? What logic level is TTL at with a floating input?What were you told to do with unused inputs?
- i connect it on the ground.
Why did you use a resistor for one R0 input, but tie both R9 inputs directly to ground?What purpose does the 220 ohm resistor serve?
- to resist the power voltage..?
What will wiring LT#, RBI#, and BI/RBO# to ground do to the decoder?Will the BCD to seven segment decoder work as you have it wired?
- i thought it just connected that way...
H = logic HIGHwhat does H, L and X means?
How would YOU know when the counter got to nine?How would YOU know when the counter got to nine? What device can you think of that could generate a positive signal when it recognized nine?
What pin(s) of the 74ls90 could you use to force the count back to zero? If you answer these, you have it made.
What logic (gate) do you need to use to decode 9?How would YOU know when the counter got to nine?
- when Q0 and Q3 is off(0).
What device can you think of that could generate a positive signal when it recognized nine?
- View attachment 100081
- The CKB....?
That's the only counter chip in the circuit...
Why did you leave one of the R0 inputs floating? What logic level is TTL at with a floating input?
Why did you use a resistor for one R0 input, but tie both R9 inputs directly to ground?
What will wiring LT#, RBI#, and BI/RBO# to ground do to the decoder?