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Doubt about design of led matrix display with 16x80 dots

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deniah

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I need advice how to drive led display with 16x80 leds. My approach is to connect anodes to 4-16 decoder 74HC154, and cathodes to MBI5026GF constant current shift registers. Refresh display is 100Hz, and characteristics of leds I have are 3.0-3.2V, max. 18mA.
According to datasheet, MBI5026 is enable to deliver max. 90mA per pin.

I already simulate this in proteus and it works but I'm not sure am I going to have enough brightness in real life.

In attachment is schematics with HC595 instead of MBI5026.

Please, any suggestions are welcome.

Regards, Refik

 

I'm also not confident the brightness. There have some delay to transfer 80 bits of data and also the duty cycle is 1/16.
I have done hardware 48X8 and 96X8, then I'm not confident to make bigger with same design. I'm thinking to use MAX7219.
 
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    deniah

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Thank you for reply.
I am doing display refresh from interrupt and while one row are displayed I'm sending data for next row, so there is no delay between.

This is my current design:



and I am thinking to change it to this:



and to drive simultaneously two group of shift registers.
At the same time two rows would be on, ie. first pass rows 1 and 9 are on, second pass rows 2 and 10 are on and so on.
In this way duty cycle would be 1/8.

What do you think?

Regards
 

Thanks for your answers.

@wavelet1208

I have one question. In your schematic I see only one 74hc138, and its 4 outputs are connected to 8 rows.
This means when you turn on first row, row 4 are also turned on, am I right?
How do you drive this display?
 

Because its 1/4 scan display,So I used one 74HC138 as a 2-4 decoder.
Some bug,in this schematic,"Line4","Line5","Line6","Line7" not used.sorry.
 

hey i want to use a 8*32(ie 8 rows and 32 coloumns) led matrix. can i use 89s52 microcontroller to drive my display. I don't want to use PIC.
 

of course,if you used 89s52,but why you not use some ARM core chip?I not use AT89S52 a few years.
 

sir the problem is i have studied 8051 which was part of our course nd found it very easy in comparison to PIC. sir der won't be any problem rite?
 

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