7-Segment with BCD shows inverted Numbers

Using Arduino Displays
1

Hey guys,

Hardware:

CL5631BW - 3 Digit 7 Segment Display
CD4511BE - BCD Decoder

Attachment:

The BCDA inputs are wired with 680 Ohm Resistor and the outputs are wired with 680 Ohm Resistors to the 7 Segment correctly.

Problem:

All Numbers shown on the Display are inverted (All segments that should be illuminated are dark and vice versa).

I think the decoder is for Common Cathodes.

Question:

Is it possible to change the mode for the decoder to Common Anode?

Thanks guys

fritzing-segment-problem.png
fritzing-segment-problem.png729×667 31.8 KB

2

dinomite:
I think the decoder is for Common Cathodes.

That is correct. As per the datasheet.

dinomite:
Is it possible to change the mode for the decoder to Common Anode?

Why would you imagine it would be? This is an essentially obsolete part, of the "CD4000" series. It is a quite impressive design for its time with the ability to actually drive up to 25 mA per segment. :astonished:

And of course, you want to multiplex this display, don't you? You need a MAX7219.

OK, as an "educational exercise" it may be plausible to get some random display and try hooking it up, but if you really want to use it for some purpose, it is vastly more appropriate to get one of the fully assembled display modules available on eBay or Aliexpress and such,

eBay
(Admittedly, presently effectively unavailable due to Covid-19 :roll_eyes: )

3

Paul__B:
That is correct. As per the datasheet.
Why would you imagine it would be? This is an essentially obsolete part, of the "CD4000" series. It is a quite impressive design for its time with the ability to actually drive up to 25 mA per segment. :astonished:

And of course, you want to multiplex this display, don't you? You need a MAX7219.

OK, as an "educational exercise" it may be plausible to get some random display and try hooking it up, but if you really want to use it for some purpose, it is vastly more appropriate to get one of the fully assembled display modules available on eBay or Aliexpress and such,

eBay
(Admittedly, presently effectively unavailable due to Covid-19 :roll_eyes: )

Thank you so much for your response, really appreciate it.

I wanted to try out to multiplex displays thats right.

I will try to get one fully assembled display module for my project :slight_smile: