Author Topic: Output extender?  (Read 681 times)

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Offline TajjbeTopic starter

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Output extender?
« on: May 25, 2020, 11:32:36 am »
I'm doing a little scoreboard project that I now got a little stuck on and want to see if anyone with experience can help me.

The scoreboard have 4pcs of 7-segment displays and a total of 22 LED's that needs to be individually controlled.
The 7-seg.disp are the  cathode-controlled type.

Is there any type of output-extender IC that I will be able to control all leds and displays via a digital stream to or do anyone got a better example
to control everything with my uC?

Here is an example of the scoreboard to help if I explain badly :P
996767-0
 

Offline madires

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Re: Output extender?
« Reply #1 on: May 25, 2020, 12:09:09 pm »
Do you need simple on/off operation or something more sophisticated with constant current, PWM and what have you?
 

Offline Nusa

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Re: Output extender?
« Reply #2 on: May 25, 2020, 01:34:52 pm »
"LED Display Driver" is a good search phrase for you. If you answer madieres question, someone may make a specific suggestion.
 

Offline TajjbeTopic starter

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Re: Output extender?
« Reply #3 on: May 25, 2020, 01:55:21 pm »
Yes as simple as on/off, something with sink output..
 

Offline madires

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Re: Output extender?
« Reply #4 on: May 25, 2020, 04:31:31 pm »
In that case a few 74HC595/74HCT595 would the job. If the 7-segment display and the 595 are powered from the same rail then a pin set to low sinks current and when set to high prevents any current flow (no potential difference). But if the 7-segment displays are powered from another rail with a higher voltage or need more current than the 595 can handle you could add transistors to switch the segments.
 
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Online MarkF

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Re: Output extender?
« Reply #5 on: May 25, 2020, 04:37:54 pm »
I love these shift register solutions...  :-DD
Just a little noise, one missed clock and ALL of the outputs are messed up.
 

Offline TajjbeTopic starter

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Re: Output extender?
« Reply #6 on: May 25, 2020, 08:15:17 pm »
Ah okey, never worked with shift register. Sounds it could help me solve this problem  :-+

@MarkF,  I will have that in mind when contructing the PCB :P
 


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