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I need help with an led question. please read details Answered

So I have had these two 7 color leds and they both have three leads a piece, if you touch two of them together you can select colors. I am trying to find a way to drive the two. I have programed a few a tinys and what not but with these i am just looking for simplicity. I have a lot of basic electronics on hand like timers, transistors and what not.. I just want to know if there is anyway to drive these leds without any programing. (i dont have any atinys or ics as such on hand). I want to cycle all the colors. right now I have a simple set up, i have a button that when pressed connects the two leads and allows color selection and after pressing it 14 times you can have all colors cycle. pretty simple. Heres a video I did a while back with two of them http://www.youtube.com/watch?v=8Wz15eLoZp4  
what Im looking for is a way to automaticaly cycle all the colors without having to press a button, (npn as a switch maybe?) cycles as soon as power runs through the circuit. any one with any info please reply. i am willing to program a chip if that what it boils down to

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vtxstar
vtxstar

7 years ago

If you are pressing a button, you may have seen THIS video about the 7color devices.

To be clear on your specification, you want the circuit to do this on power up:
  • Strobe the control line of the LED 14 times only
  • Go idle until the next power cycle
If so, you need counter that cycles the control line 14 times and then stops. Today, this is probably easiest done with a PIC or other small microprocessor. It could be done with logic gates but that would take up a lot of space and require several connections.

-=Doug
0
vtxstar
vtxstar

7 years ago

If you are pressing a button, you may have seen THIS video about the 7color devices.

To be clear on your specification, you want the circuit to do this on power up:
  • Strobe the control line of the LED 14 times only
  • Go idle until the next power cycle
If so, you need counter that cycles the control line 14 times and then stops. Today, this is probably easiest done with a PIC or other small microprocessor. It could be done with logic gates but that would take up a lot of space and require several connections.

-=Doug
0
Josehf Murchison
Josehf Murchison

Answer 7 years ago

I screwed up there is should be resistors to both of the transistors like this.

three pin led.bmp