# Need Help with Bipolar LED's and minimal digital pins

Hi,
In the photo below I have drawn a ruff diagram of my idea to use bi polar LED's. I will be using 8 LED's and don't have 16 pins for both the blue and yellow pins from the LED (Blue and Yellow are the bipolar colours from the LED). What i am trying to accomplish is I can control all 8 LED's separately and choose to switch all of them from blue to yellow if I wish with only using a total of 10 pins (8 for the LED's and 2 for the switching between either blue or yellow).

The voltage in is 9.6v and then splits to the 8 LED's (In this diagram I didn't show all 8 because they all have the same circuitry). Then Pins 3-10 will control the LED's, ON/OFF state. After that the Pins 1 and 2 are attached to all the LED's (Pin 1= Blue Pin 2= Yellow).

So what I am asking is will this work or will it not and maybe even some suggestions as well are appreciated.
NOTE: The schematic doesn't show the two legs for the Blue and Yellow on the LED, so just imagine they are their.

Thanks, Ken

Why don't you take some time and document that which you propose instead of asking that the rest be imagined, or implied, or assumed?

Help would be better than criticism. I am new to this and would like some assistance that's all.

I have not critcised you.
You stated that your proposal is incomplete but you complain that I ask for clarification?

I suggested that you document what the devil you're on about as stuff like

Kenn13542:
... I have drawn a ruff diagram... So what I am asking is will this work or will it not and maybe even some suggestions as well are appreciated.
NOTE: The schematic doesn't show the two legs for the Blue and Yellow on the LED, so just imagine they are their.

isn't "helpful", or conducive to your desire, presumably, to garner "help" at all.

You could use two shift registers to control 16 pins.

That could be a lot simpler than a whole heap of transistors.

As for your proposal, I'm not sure. Try making up one leg of it (one resistor, 3 transistors and one LED) and see for yourself. But I think you are going to end up with a whole lot more parts than two shift registers and one resistor per LED (leg).

Ok thanks, I'll look into shift registers and see what I can find.
Thanks, Ken

In the photo below I have drawn a ruff diagram of my idea to use bi polar LED's.

The rough diagram does not show bi polar LEDs at all.

These are LEDs that show one colour when connected one way round in a circuit and the other colour the other way round. Therefore to drive them with a single rail system you need a circuit called a H-bridge, these are normally used for controlling motors.

So what do you actually mean?
Do you have a bi polar LED or do you have a two colour LED, if so is the package common anode / cathode / access to both?

I did mention that the schematic diagram I did was done in a program that only had a one Colour LED.

NOTE: The schematic doesn't show the two legs for the Blue and Yellow on the LED, so just imagine they are their.

But the LED is a bi polar LED with 3 legs for blue, yellow and ground.

But the LED is a bi polar LED with 3 legs for blue, yellow and ground.

If it has three legs it is not a bipolar LED.

the schematic diagram I did was done in a program that only had a one Colour LED.

So what you should do is to use two symbols and put a note on the diagram.

NOTE: The schematic doesn't show the two legs for the Blue and Yellow on the LED, so just imagine they are their.

My imagination has a hard time deciding if they are common anode or common cathode LEDs and if so where the missing wires actually go.

As drawn the diagram is a nonsense, so I will use my imagination and say yes it is perfectly fine.

Please note the quality of an answer is only as good as the quality of a question.

Thankyou for the tip on putting 2 leds instead of one on the schematic because the program doesn't have it and also someone finally answering the question.

It does have 3 legs and says its bi polar, so is that not the proper term?

Kenn13542:
It does have 3 legs and says its bi polar, so is that not the proper term?

I'm guessing he meant bi-color.

The rest of the text looks machine-translated so the meaning might have been lost.

Ok cool, thanks for everyone's help.

the polar has to be automatically reserve by the circuit in order to make it flashing.

That phrase from the web site is pure nonsense. If reserved means reversed then it makes more sense only it does not apply to what they are selling.

Polar is short for polarity and there are some LEDs that show one colour when powerd in one direction and another colour when powered in the other. This is not the case here.

If you want to do another diagram showing the common cathode and where all the base signals come from we will be happy to comment on it.

Thanks for that tip, I'll see how it goes when my ED's arrive.
Thanks, Ken