• This topic has 6 replies, 3 voices, and was last updated 1 week, 6 days ago by LectronFan.
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    • #8223
      LectronFan
      Moderator

      Hi all,

      How about adding a new module to the Digital Logic Lab which is able to display the numbers 0 to 9 in Decimal and 10 to 15 in Hex ?

      Well, here it is !

      This module is a nice add on for the Lectron counter 4520. It simply snaps at the right of it and will display the numbers presented at it’s Q0 -Q3 inputs. The same Q0-Q3 is available at the right of the new display module so it can be placed in existing circuits without the need of  rewiring it.

      So, what is HEX ?

      Well, following table explains it all :

      HEX Table

      Normal  display drivers such as the CD4511 only display the numbers 0 to 9. The HEX numbers A,B,C,D,E and F are simply ignored.

      To display these, we will need a special driver chip which is not available anymore (obsolete).

      I decided to use a microcontroller with some discrete components. It scans the inputs and outputs a HEX number to the 7 segment led display. This happens at a clock rate of 8 Mhz, fast enough for our Lectron circuits. The module is very power friendly thanks to the use of a segment display operating at a very low current (typical 1mA per segment). It emits a bright readout though.

      It is safely powered by 9V thanks to a small voltage regulator build in the display module.

      Here are some pictures :

      HEX display1

      HEX display2

      HEX display setup

      And here a video of the working principle : Lectron HEX display

      Many greetings,

      Frank

       

       

       

      • This topic was modified 2 weeks, 6 days ago by LectronFan.
      • This topic was modified 2 weeks, 6 days ago by mwpeters75. Reason: Changed font and size styling for easier reading
    • #8226
      mwpeters75
      Keymaster

      Hi Frank,

      Wow, this is really excellent customization work.  A hex display has never been done before (to my knowledge), congratulations!  I especially appreciate the video showing the new circuit in action.  Wonderful!  

      Your vacation has really put you into high gear 🙂 

      Welcome back and thank you for this new circuit!

      Best,
      Michael

      • This reply was modified 2 weeks, 6 days ago by mwpeters75.
    • #8238
      Guenni75
      Moderator

      Hi Frank,

      that is really helpful and great work, thank you!

      Which obsolete hex driver do you mean? Perhaps I may find a collector of these specials with that IC…

      May I offer your block in my (our!) Lectron File Card Collection?

      Best,

      G.

      • This reply was modified 2 weeks, 3 days ago by mwpeters75. Reason: Changed font and size styling for easier reading
    • #8240
      LectronFan
      Moderator

      Hello Guenther,

      Very kind of you to check for this chip.

      The driver chip mentioned is a MC14495 and can still be found but it’s quite expensive.

      And for fellow Lectroneers who want to build this module, it would be easier to use a ATTINY84.

      It has the advantage that it costs only €2 and that the program can easily be adapted.

      Also the chip is widely available.

      I will gladly share the code if anyone’s interested and I still have a few PCB’s.

      I would be honored if you would add this module to your library, many thanks.

      Maybe Lectron is also interested ?

      Many greetings

      • This reply was modified 2 weeks, 3 days ago by mwpeters75. Reason: Changed font and size styling for easier reading
      • #8247
        mwpeters75
        Keymaster

        Hi Frank,

        Sadly, there will likely be no further Lectron System development as Mr. Kopperschmidt has ceased being involved with Lectron, GmbH.  There are no plans that I am aware of regarding replacing Mr. Kopperschmidt’s role as developer and designer.  I hope that I am wrong about this!

        • This reply was modified 2 weeks, 3 days ago by mwpeters75. Reason: Changed font and size styling for easier reading
    • #8253
      Guenni75
      Moderator

      I ordered the MC14495 for EUR 1.36 including shippment – let’s see if / when it will arrive…

      G.

      • This reply was modified 1 week, 5 days ago by mwpeters75. Reason: Changed font and size styling for easier reading
    • #8258
      LectronFan
      Moderator

      Hi Guenther,

      This is really a great find !

      I will make a PCB for this chip and try it out.

      More info soon …

      • This reply was modified 1 week, 5 days ago by mwpeters75. Reason: Changed font and size styling for easier reading
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