LED ARRAY WITH SLIDE
The led array show three diferents messages, the last one is a slide
The led array show three diferents messages, the last one is a slide
According to wikipedia:
Charlieplexing is a technique for driving a multiplexed display in which
relatively few I/O pins on a microcontroller are used to drive an array
of LEDs.
The method uses the tri-state logic capabilities of microcontrollers in
order to gain efficiency over traditional multiplexing. Although it is
more efficient in its use of I/O, there are issues that cause it to be
more complicated to design and render it impractical for larger displays.
These issues include duty cycle, current requirements and the forward voltages
of the LEDs.
Charlieplexing method help to manage many LEDs with few microcontroller pins
List of needs for this PCB:
- Digital input.
- LED array
In this case, I have used Kokopelli to design the PCB. I've added a input
signal.
Script will be explained on the next section.
Download c code, cad and make file here
Wow... yes!
I want that background of led array be black, because of contrast, in
other hand, I am making the final project at Fab Lab Sitges and... there
is no EPOXY for the second layer.
(This PCB have 2 layers, the isulation from 2 layers is a layer of epoxy)
Well, I have no EPOXY, so I decided to try it with vinyl, so I designed
and cutted the layer.
I advise everyone to NOT use vinyl as an insulating layer. Every solder is a olimpic final. If I stay more than 1 second, vinyl start to burn, so I have to soldering "bee sting style". No way...
Let's debug all traces, leds, voltaje, ...
Looking for some short cut, loose wire....
Soldering out some and come back again.
Checking after any action, but still don't work.
Relationship between pins and led... and...
YES!!! I GOT IT! Is pin number PA3, it's not working.
One option is to change the microcontroller, but PA5 is free now, I want
to check if I change PA3 for PA5 it will work.
Let's try.
You can see a little red cable between PA5 and PA3. I put a piece of vinyl
under the cable in order to avoid contact.
After that...I have to change the script, now PA5 is PA3.
Now it is working!
I want to show a message in a slide window, let's work on it. Make
all the steps that have to do the slide and script them one by one. At
this video you can see a demostration.
Download the c script
After all that documentation is difficult to have a general view of all
interactions and communications in my final projects. I have made this
video to explain them.
Enjoy!