Counter that counts from 99 to 00 with start/pause button.

Thread Starter

p3triix

Joined May 12, 2021
43
i managed to make the counter work with the button, thank you alot Eric, now i would like to know if you could help me in two more things, i need to make the counter stop at 00 withou restarting and when i turn on my circuit it automatically start, but i wanna make it start when i press the button
1621086409138.png
 

Thread Starter

p3triix

Joined May 12, 2021
43
i read in some forums in the internet that i need to use p0, p1, p2, p3 to set the value where i wanna to stop, but when i set /PL in low level the counter doesn't work
 

ericgibbs

Joined Jan 29, 2010
19,015
hi p3,
This clip from a simulation, shows the method I used for manual Start/Stop, also stop at '00'.
It looks a little complicated, but it uses a Bistable which Clocked On/Off with a push button.
This starts and manually stops the count down.
The Bistable is also Reset by the tdnb, Down count output of the second 74192.

Do you follow OK.?
E
 

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Thread Starter

p3triix

Joined May 12, 2021
43
hi p3,
This clip from a simulation, shows the method I used for manual Start/Stop, also stop at '00'.
It looks a little complicated, but it uses a Bistable which Clocked On/Off with a push button.
This starts and manually stops the count down.
The Bistable is also Reset by the tdnb, Down count output of the second 74192.

Do you follow OK.?
E
can you tell me what is the "tdnb" i think that is not a common initials in my country? my teacher never mentioned that before, also as i can see that i need the preset and clear to make it start with the push button instead of automatically, so the preset goes at PL in 74ls192 and CLR goes at tdnb
 

ericgibbs

Joined Jan 29, 2010
19,015
him
The 74192 datasheet shows an output pin marked as TC/D Terminal Count Down , which means when the Counter reaches Zero this pin goes LOW.
I use the letters tdnb for that pin in my diagram, the B tells me its the 2nd 74192 IC.

OK.?
E

Would you like to see the full LTSpice simulation plot.?
 

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Thread Starter

p3triix

Joined May 12, 2021
43
him
The 74192 datasheet shows an output pin marked as TC/D Terminal Count Down , which means when the Counter reaches Zero this pin goes LOW.
I use the letters tdnb for that pin in my diagram, the B tells me its the 2nd 74192 IC.

OK.?
E

Would you like to see the full LTSpice simulation plot.?
oh, i see, i understand now, i would like to see if possible, but i would like to know if the preset from JK is connect to /PL at 74ls192
 

ericgibbs

Joined Jan 29, 2010
19,015
hi p3,
I don't expect you fully understand the simulation at this stage of your learning, [hopefully one day.;) ] but it is just to show you that your basic circuit works.
Ask if you have query.
E
 

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Thread Starter

p3triix

Joined May 12, 2021
43
hi p3,
I don't expect you fully understand the simulation at this stage of your learning, [hopefully one day.;) ] but it is just to show you that your basic circuit works.
Ask if you have query.
E
i understand what you did, everything is working like i was expecting but the part of stoping at 00 is not working, it stop at 99, i'm pretty sure that is something related to the D0,D1,D2,D3 ports, but thanks alot
 

ericgibbs

Joined Jan 29, 2010
19,015
hi p3,
I would recommend that you don't use the decoded D0,..D3 outputs as a control method, it will give you problems with timing.
Use the TC/D pin on the last 74192.

E
 

Thread Starter

p3triix

Joined May 12, 2021
43
hi p3,
I would recommend that you don't use the decoded D0,..D3 outputs as a control method, it will give you problems with timing.
Use the TC/D pin on the last 74192.

E
well, one problem is that i can't connect both MR at each other, because it doesn't let the counter leave the 0, i'm really having a big problem to make it stop at 0, do you have any idea about what can cause that ?
 

ericgibbs

Joined Jan 29, 2010
19,015
hi,
You have not wired this part as I suggested.
Also the two Count Up clocks should be connected to +5V

You said you wanted a 99 to 00 Down Counter.

E
Also in small image, please show ,ore clearly how the D inputs and the PL are connected.??
 

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Thread Starter

p3triix

Joined May 12, 2021
43
hi,
You have not wired this part as I suggested.
Also the two Count Up clocks should be connected to +5V

You said you wanted a 99 to 00 Down Counter.

E
Also in small image, please show ,ore clearly how the D inputs and the PL are connected.??
i didn't connected the two count up in 5V because i need to control them using a push button, and in the small image the ports 9 and 15 are connect at VCC and 1 and 10 are connect at GND in both circuits to make the 9 according to the truth table, i did all connections according to you , but that is a old draw
 

ericgibbs

Joined Jan 29, 2010
19,015
i didn't connected the two count up in 5V because i need to control them using a push button,

hi,
What are you going to use these two push buttons for.???
It may mean a change in the circuit design.
E
Where are pin 11's, PL connected.?
 

Thread Starter

p3triix

Joined May 12, 2021
43
i didn't connected the two count up in 5V because i need to control them using a push button,

hi,
What are you going to use these two push buttons for.???
It may mean a change in the circuit design.
E
Where are pin 11's, PL connected.?
i redraw the schematic to show you the connections that i did.
i'm using the push button to change the digits at the display.
4181d112-deb3-4a4d-8b52-1aa8e39d1bc9.jpg
 

Thread Starter

p3triix

Joined May 12, 2021
43
i didn't connected the two count up in 5V because i need to control them using a push button,

hi,
What are you going to use these two push buttons for.???
It may mean a change in the circuit design.
E
Where are pin 11's, PL connected.?
if you want i can send you the program that i'm using and the file of my project
 

ericgibbs

Joined Jan 29, 2010
19,015
hi p3,
I would like that, thank you.:)
We can then compare notes.

BTW: if you intend using one of the extra push buttons to change the Up Clock input, remember the Down Clock pin MUST be High,
E
 

Thread Starter

p3triix

Joined May 12, 2021
43
hi p3,
I would like that, thank you.:)
We can then compare notes.

BTW: if you intend using one of the extra push buttons to change the Up Clock input, remember the Down Clock pin MUST be High,
E
i uploaded the program in mega.nz so you can download it, the program is in spanish so i don't know if you will understand what is write in the program https://mega.nz/file/zlM0mbYS#RnN1w2d4DRtcEkkknuAzPNRsrmysWAMYhGn0S4gHHoA
also this is the file that i'm using, you can open it in the program by choosing the folder icon and choosing the .txt file
 

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