Yann Guidon / YGDES-
Version 2.0
08/22/2016 at 01:19 • 2 commentsI just updated the PCB and that's pretty neat indeed !
- No more series resistors, less soldering, smaller BOM (if you work @3.3V)
- LED orientation is less critical, more forgiving for assembly blunders (as long as the LED are reverse-wired, and you update the segment definition in the software)
- single-sided PCB ! Routing is even easier ! No need to connect every end of every segment, because they are chained in pairs :-)
So it looks like the protection diodes are a "feature" that can become beneficial if it is used creatively :-)
The Eagle file is updated as well and a PCB run is started, stay tuned !
-
Damned protection diodes...
08/21/2016 at 23:30 • 0 commentsOK, @al1 found a major hicup in my design. The reverse diodes mess with my idea.
The cool news is that the #DYPLED uses another style of multiplexing and is immune to the problem.The bad news is that I have wasted some PCB surface.
But this is only a little setback. And if parallel wiring doesn't work, serial might !
I measured about 0.7V reverse voltage. There needs to be about 3.5V to turn one of the LEDs on. This might be possible...
----WW------|>|-----|<|-----
It works !
At 3.3V, without limiting resistors, the luminosity is quite good, giving a bit of headroom for multiplexing.
4014 LED minimodule
A cheap, small module that displays two 7-segments digits with simple multiplexing