Fun with shift registers - The 74HC595

In this project I will be using the 74HC595 to extend I/O's from a PLC for the purpose of driving several segment displays. Instructions, schematics, and a parts list is available at wilsonmj.net

Category:

Howto & Style

Tags:

• 74HC595
• Shift
• Register
• PLC
• Cubloc
• Segment
• Display

[mirabilis]

You have extended the "O"s, not the "I"s. ;)

[fabmkk]

Great video, but can't access your website, it says 403 Forbidden, thanks anyway! :)

[billynightmare]

thanks, this helped me out :)

[TunioMir]

@krisimpossible yes, using pwm

[Pilbromatic]

Cheers for the video, great help with some good info in there.

So you suggest that you could daisy chain more of these units together? I'm looking to run approximately 20 seven segment displays - So all this would be fine and without flicker over the single chain?

Thanks again!

[Aev308]

@krisimpossible use a digital trimpot to control the current to Vin on the displays

[rcisthedriver]

@krisimpossible I'm quite sure you can fade LEDs from a 595, you'd obviously have to use PWM to do that.

[krisimpossible]

Does anyone know if a 595 can fade LEDs? Thanks!

[graymalkin1234]

The biggest limitation of the shift register is the current reduction, while one LED uses few mA, hundreds use quite a few. Ben Heck made a screen using 512 red leds and it drew over 3.5 amps

[joebro391]

thanks, this was really informative! but how would you do a similar set-up, but with a 16-segment display? thanks. -Joe