PWM rgb ledstrip

Hello,

I'm having some issues with PWM-ing a rgb ledstrip.

I've bought the following ledstrip: RGB LED strip tutorial (3 meters/30 leds p/m => 90 rgb leds => 270 leds)

I'd like to make my own RGB-led controller using RF to turn it on/off/change colors. This means I have to use VirtualWire. This takes up my timer1. So I only have 4 pwm pins left. I've tried some combinations, but somehow this always results in flickering leds when I turn them down to ~25%.

I've thought of buying the tlc5940. But if I'm correct, the library for the tlc5940 uses timer1 and timer2. So I can't use virtualwire in combination with tlc5940?
Now I've ordered WS2801 IC - COM-10444 - SparkFun Electronics, but I'm not sure if this will solve my issue.

Can someone enlighten me on what my problem is here? Is it because I use 2 different timers to PWM the ledstrip? Or is it possibly the powersupply? Will the WS2801 solve my issue?

If the strips are continuous you only need one PWM output pin per color. If things start to flicker noticeably I would suspect the power. At 600 mA/m and 3 meters of lights you need a 1.8A (or higher) 9V to 12V power supply. What is the power rating on your power supply?

Yes it is continuous. I've bought a 12v/5A power supply. This should be plenty right? If I turn the leds to 100% (analogWrite(x, 255)), the strip is not flickering. Only if I turn it down to ~25% it's very noticeable. Could this still be a power related issue?

Do you have power transistors for each color?

Flickering almost certainly leads to dirty power/ground issues.

Cypher87:
I'd like to make my own RGB-led controller using RF to turn it on/off/change colors. This means I have to use VirtualWire.

How so? I built several RF controlled modules last year with RGB LED strings. My setup consisted of two strings containing 20 RGB LEDs each, driven by WS2801s (one per RGB LED). I used bit banging to control the strips. I used an nRF24L01+ RF module which uses SPI to communicate with the µC. Didn't use VirtualWire.

One module acted as a master, sending RF signals to the others, telling them how to change.

tekket:
Do you have power transistors for each color?

Flickering almost certainly leads to dirty power/ground issues.

Yes I do have power transistors. If it would be a dirty power/ground issue, shouldn't it be flickering disregarding the pwm duty cycle?

KirAsh4:
How so? I built several RF controlled modules last year with RGB LED strings. My setup consisted of two strings containing 20 RGB LEDs each, driven by WS2801s (one per RGB LED). I used bit banging to control the strips. I used an nRF24L01+ RF module which uses SPI to communicate with the µC. Didn't use VirtualWire.

One module acted as a master, sending RF signals to the others, telling them how to change.

Even so, the flickering shouldn't occur anyway rights? Using pins 3,5 and 6?

Cypher87:
Even so, the flickering shouldn't occur anyway rights? Using pins 3,5 and 6?

Well, I'm sure your circuit isn't the same as mine. I did not have flickering issues with PWM controlled brightness on LEDs, so yeah, I'd say something's up. Can you post a schematic of how you have things wired up, what components and such? Perhaps collectively we can figure out what's going on ...

This is basically what my schema looks like:

This is (of course) without the RF receiver. Which has a gnd, 5v and a data pin.

The npn I took of a rgb controller like this one:

Two of them say: d3002, 0604, MO235F
The other one says: mdd1653

Only suggestion I can think of is to try powering the LEDs with a separate 12v power source. I'm wondering if the operation of the arduino if causing the VIN voltage to waiver on you.