I have an RGB LED strip that has a VCC and RGB that is ground. I currently am trying to be able to program the LED strip, but the only tutorials I can find are for programming the RGB as VCC and using a ground. I would like to provide 9V to the strip but 12V would be suitable. How do I integrate a 9V into the circuit?
The current setup is in the attachment. I understand that I need a transistor for each Red or Blue or Green that I want to be able to control. Looking at the flat side of the transistor, the left most pin is grounded. The middle pin connects to my arduino. The right pin connects to the led strip. I have this done for 2 of the 3 colors due to the fact that I need another transistor. Besides that fact how can I wire the 9v supply into the circuit?
Easiest way to control the is to apply 12V to the + of the strip (common anode) and then use 3 transistor to connect the RGB (cathodes) to GND.
Or use a shift register that can handle high currents and voltages if you have a lot of them.
LED strips are typically 3 LEDs in series with a current limit resistor, connected in parallel to additional groups of 3.
I have a small board with arduino functionality and 3 shift registers that can drive 8 RGB strips.
Or 24 monocolor LED strips.
What attachment ?
Post a link for the hardware you are using (led strip)
have an RGB LED strip that has a VCC and RGB that is ground.
The current setup is in the attachment. I understand that I need a transistor for each Red or Blue or Green that I want to be able to control. Looking at the flat side of the transistor, the left most pin is grounded. The middle pin connects to my arduino. The right pin connects to the led strip.
Right ? Left ? What does this mean ?
If you are trying to say you want drive the RGB LEDS using switching devices to sink the current (ie: transistors /mosfets/ TLC5940/WS2801) there are numerous tutorials on how to do this.
I had done one project related to LED strip. But that was not an RGB LED strip. But I had integrated 12V in arduino circuit using ULN2803 integrtaed circuit. I had published the circuit and program in my blog. Read more about my circuit at:
You have no resistors in the base of that transistor, you will damage the transistor and arduino like that.
The strips are designed to run off 12V you can not use 9V. The are also designed to be controlled by grounding the red, green and blue lines, there is little you can do to change this.
ULN2803 is open collector darlington arrangement with base resistors built in.
It sinks current, just as shown.
LED strip may or may not work from 9V - might just be on the dim side, 3 Red LEDs at ~2.2V Vf would turn on tho. 3.2V, 3.5V Vf LEDs maybe not. Every dumb LED strip (non-addressable strips) I've seen so far has a current limit resistor built in with every 3 LEDs.
