Jump to content

7-Segment-LEDs


nILS

Recommended Posts

When I was fiddling around with that idea last night i noticed that it could be done quite easily with some additional hardware:

All you'd have to do would be to run the power for the LEDs (for example the LFOs 6 LEDs) thru a dipswitch or hardwire it to the needed pins of the 7 segment LED. If you do that with all 6 LEDs you have a simple 7 Segment display for the numbers 1-6.

Link to comment
Share on other sites

hmm, just thinking..

Under MIOS:

Is it possible to use 7segment displays (3digit, 0-127)

together with encoders instead of Ledrings?

howmany of these could be used then with 1 DOUTX4?

(7common wires for all digits + 1 per digit?

makes..... 32-7=25... so 8 times 3digits, correct ?)

& if it is possible, howmany per core ?

thanks for any info on this :)

Link to comment
Share on other sites

Ok, so according to:

http://www.ucapps.de/mios_download.html

http://www.ucapps.de/mios/leddigits_16.pdf

How to drive 16 LED digits with a DOUTX4 module (schematic: leddigits_16.pdf). Up to 64 digits can be driven by a single core in this way.

The MIOS intro says:

http://www.ucapps.de/mios.html

handling of up to 128 LEDs, relays, Digital-Analog-Converters or similar output devices. In multiplex mode a nearly unlimited number of LEDs, LED rings and LED digits can be driven

Hmm.... 64 is near unlimited ?  :D

I see that on the schematic that the digits are split in 2 groups of 8, each sharing the 8 wires...

Could it be made to have 3 groups of 8 digits ?

Does it have to be common anode displays, is this required by the software or the hardware ?

Thanks for more light on this :)

Link to comment
Share on other sites

These are driver examples, the possibilities are unlimited, if you plan to use it with other configurations, you are able to change the code in order to adapt it to your hardware.

If you want to connect more than 64 LED digits (512 LEDs by the way...), just time-multiplex 16 digits (makes 3 shift registers for 16 digits -> 80 digits = 640 LEDs) --- they won't be so bright like with the 8x8 configuration, but you shouldn't notice flickering.

Another solution would be the use of an additional 7-segment decoder (idea by Pilo), so that one DOUT register can drive 2 patterns instead of 1. This would allow to drive 2*16 = 32 digits with 3 DOUT registers, makes 160 digits with a single core, makes 1280 LEDs

As I wrote: feel free to change the driver for your needs ;-)

Best Regards, Thorsten.

Link to comment
Share on other sites

Another solution would be the use of an additional 7-segment decoder (idea by Pilo), so that one DOUT register can drive 2 patterns instead of 1. This would allow to drive 2*16 = 32 digits with 3 DOUT registers, makes 160 digits with a single core, makes 1280 LEDs
Hey Thorsten, for driving 7segment, can't we use an interface made with 74sn7447 (or 7448 )? It will use less DOUT pin...

I have been thinking about this, but...

these are BCD-2-7seg decoders, so actually they only would reduce the number of common lines, right ?

like instead of 8linesx8digits one would get 4linesx8digits+4linesx8digits ?

But would a 3 to 8 decoder (3^2=8 ) also work then ?

or has it got to be a 'driver' IC ?

(plz forgive my lack of knowledge of electronics terminology)

best regards

Link to comment
Share on other sites

Hi,

like instead of 8linesx8digits one would get 4linesx8digits+4linesx8digits ?

no - you could use one DOUT register to select 2-of-16 digits at once (two digits selected at the same time), and another DOUT register (which drives the two 7-segment decoders) to send the patterns.

But would a 3 to 8 decoder (3^2=8 ) also work then?

Sure - this would increase the max. number of digits even more! It only requires some (small) modifications in the driver. Just begin to work with the digits and you will notice how easy they can be handled. :)

It would be nice if you could write a report (could be uploaded to the MIDIbox portal) which describes your variations and gives some programming examples so that other people can don't have to re-invent the wheel.

Best Regards, Thorsten.

Link to comment
Share on other sites

Hello,

I still am struggling with certain aspects  :-/

http://www.ucapps.de/mios/leddigits_16.pdf

On this schematic, we have 1 DOUT module with 4 shift registers; could we call the black lines 'scanlines'  and the green & blue lines 'datalines' ?

Then my question is, *must* the scanlines & datalines be on different shiftregisters ? (like it is done here)

or would it be possible to have like e.g. 5 datalines & already 3 scanlines on the 1st shiftregister(SR) ?

Then 5 scanlines & 3 datalines on the second SR; 2 datalines & 6 scanlines on the 3rd SR etc...

Thanks again

Link to comment
Share on other sites

Yes, this is possible by changing the addressing scheme (please do some experiments with the circuit first in order to understand how it is working... it took me 15 minutes to write this example, but I don't want to explain all variations, because this would take hours)

Best Regards, Thorsten.

Link to comment
Share on other sites

OK, thanks for clearing this up :)

I'll do some experimenting for sure but I was thinking about using 2-1/2digit LEDdisplays, they have a multiplexed connection (5+4wires) & I just wanted to know before I start building some hardware that perhaps would possibly never work with MIOS.

MFG

DriftZ

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...