counting a 24 pulse signal

[ericgibbs]

just checked and that is the same diagram i followed, the pins discribed are wired as they should be,

but when i said Q2 i was looking at the chip upside down, its Q5 that does nothing

hi,
Are you saying Q5 does nothing even when the RESET pin of the 4024 is tied to 0V.??

If the RESET is 'fully' connected as shown in Mike's circuit, then Q5 will be a very pulse which you will NOT see on the test LED.

I would suggest that you, for testing, connect the RESET pin #2 to 0V.

All the Q's should flash your LED test probe.

EDIT:
Checked Mike's original LTS plot output and it shows that Q5 should be long enough to see a flash.

 

[MikeMl]

just checked and that is the same diagram i followed, the pins discribed are wired as they should be,

but when i said Q2 i was looking at the chip upside down, its Q5 that does nothing

See what happens after I go to bed.

Nex, I assume you have a schematic diagram that shows which pin goes where. If not, start from my schematic, and
create a diagram which shows pin numbers on the chips, where each chip gets its power/gnd, where all unused input pins are tied, and then post it here. Then we can lead you through the debugging with reference to pin numbers.

I like your "logic probe", consisting of the LED and resistor.

 

[NeX]

hi,
Are you saying Q5 does nothing even when the RESET pin of the 4024 is tied to 0V.??

If the RESET is 'fully' connected as shown in Mike's circuit, then Q5 will be a very pulse which you will NOT see on the test LED.

I would suggest that you, for testing, connect the RESET pin #2 to 0V.

All the Q's should flash your LED test probe.

EDIT:
Checked Mike's original LTS plot output and it shows that Q5 should be long enough to see a flash.

sorry now i am not using a test LED i am attaching the reset to each output to see what happens to the LED, i will try making a test LED and testing it with that.

 

[ericgibbs]

See what happens after I go to bed.
I like your "logic probe", consisting of the LED and resistor.

Mike,
Its now close to my bed time, you can take the late shift..

Regards

 

[NeX]

haha, yea ok i will make up a diagram,

i followed your diagram and translated it to real life using the data sheets but i did it on the fly, i just delt with one connection at a time. i have double checked them and they seem fine but i think i will start from scratch, draw up a diagram, mount them all on a bit of strip board and do it that way.

but for now, today is valentines day so i have to deal with the lady friend first!

 

[NeX]

ok i went and did a diagram anyway,

sorry about the quality i did it in MS paint

 

[NeX]

i might redo this diagram in a bit to make it a little more neater

 

[NeX]

right, i just redrew the diagram, chopped off the extra 4 input NAND,

i built this up using all brand new parts, and it is doing exactly the same as the one before, about 10 times too fast

 

[MikeMl]

ok i went and did a diagram anyway,

sorry about the quality i did it in MS paint

Looks ok. Like Eric said, temporarily ground pin 1 of the counter (after removing the wire). That will make the counter count without interaction from the reset circuit. Each bit of the counter Q1, Q2, Q3 should halve the flash rate.

I wonder if the input clock is counting much faster than you think it is?

 

[NeX]

Looks ok. Like Eric said, temporarily ground pin 1 of the counter (after removing the wire). That will make the counter count without interaction from the reset circuit. Each bit of the counter Q1, Q2, Q3 should halve the flash rate.

I wonder if the input clock is counting much faster than you think it is?

i will give that a try now, hang on do you mean pin 2?

i can't be sure exactly how the clock is working because i have no way of testing it, but all the paper work i have says it is 24 pulses, and other people have confirmed this.

but maybe its the way the clock works, the clock pulses 8 times then stays low, then again another 8 times, and low and then one more pulse of 8 for the 24 signal, when it is off, the clock is held high.

 

[NeX]

right, i grounded the reset pin and ran the LED to each of the Q outputs in turn.

Q7 was about two pulses a second, (double what i am after)
then Q6 was twice that, and so on, so it seems like the ripple counter is working fine, it looks like a problem with the clock, either its not what i think it is, or its a very messy signal...

i am very sure that it is 24 pulses in groups of 8, but i am not sure how perfect the signal is

 

[NeX]

ok sorry everyone, i have just found out that 8 pulses = 1 byte, and there are 24 bytes per beat, making the clock pulse 192 per beat not 24, which explains a lot...... back to the drawing board it seems...

 

[NeX]

right, i had a 74161 4 bit counter laying around, after wireing it up with Q4 as the output feeding the original circuit and not gated to the reset everything is fine,

so thanks very much for everyone's help!

one last thing if someone is up for a challenge. if the music is stopped when the light is on, it stays on, is there any way to make the light stop when the clock stops?

 

[MikeMl]

If you reconnect the Reset circuit, that should reset the counter back to the all-Zeros state, which should turn off the LED if it happened to be on. The Reset should be wired to the "prescaler" , too. There are two extra bits in the 4024 which could divide the incoming clock by an additional factor of 4. Unfortunately, you are one bit short of dividing by an extra factor of 8. A Dual D 4013 could be added.

 

[NeX]

If you reconnect the Reset circuit, that should reset the counter back to the all-Zeros state, which should turn off the LED if it happened to be on. The Reset should be wired to the "prescaler" , too. There are two extra bits in the 4024 which could divide the incoming clock by an additional factor of 4. Unfortunately, you are one bit short of dividing by an extra factor of 8. A Dual D 4013 could be added.

i reconnected the reset circuit and the light stays on, no matter what, now. the clock is low when the unit is switched on, then when the music is stopped it stays high.

i am going to have a look at these 4013s thanks

 

[ericgibbs]

i reconnected the reset circuit and the light stays on, no matter what, now. the clock is low when the unit is switched on, then when the music is stopped it stays high.

i am going to have a look at these 4013s thanks

hi nex,
If you have a spare 4024 on the bench you can connect that in 'series' with the existing one, this will give the extra division stages if required.

 

[NeX]

hi nex,
If you have a spare 4024 on the bench you connect that in 'series' with the existing one, this will give the extra division stages if required.

thats the problem i only have 3 of them, i am on my third one now to see if i can do a final neat version

 

[NeX]

just to check, the capacitor in the reset circuit, should that be an electrolytic one? i am useing a ceramic disk one. i assume the point of it is to charge up and discharge, which might be why the reset bit is not working

 

[NeX]

this diagram works fine except for the reset.

if i stop the music when the light is on, the light stays on. but if i then start the music the light flashes in time,

if i start the music when the light is off then the light comes on every other beat, so its not flashing as soon as i press play, its taking a second to fill up the counters.

so, first of all is there a way to get it to start flashing instantly?

and secondly what am i doing wrong as far as the reset goes?

 

[MikeMl]

I'm working on it. Wait for me to post. In a nutshell, the RESet circuit input still has to be taken from the raw clock; not the partially divided clock... So, it looks like the clock is 16 times faster than you originally thought it was?