Programming Led Strips

VEX V5 Technical Support
#1

I was wondering how to program led strips. I have the led soldered to a 3 pin wire that i plan on plugging into the digital port. I have looked into other threads that have been posted about this but none of the programs there worked for me. So i was wondering if anyone can help me with this.

#2

I don’t have experience, but I’m going to guess that you just use a simple variable or something?

void turnOn
{
    SensorValue[digital1] = 1
}

As I said, I’m not experienced, but this is how I guess it would happen?

#3

@Riley Thanks, but it did not work. I have LED’s

#4

Try what @factorsofx said in this post:
https://vexforum.com/t/led-strip-lights/28893/1

Taken form this thread:
https://vexforum.com/t/led-strip-lights/28893/1

If you go into the depths of the code in the link on the data sheet, you would see that Adafruit_NeoPixel.cpp sends RGB values and sometimes a white value. Not sure when they do that or why if it supposed to work with the same strip of lights.

This won’t work directly in robot C but am just showing you the setting of R G and B values per LED light. Sent the R and G and B values

// Set pixel color from separate R,G,B components:
void Adafruit_NeoPixel::setPixelColor(
 uint16_t n, uint8_t r, uint8_t g, uint8_t b) {

  if(n < numLEDs) {
    if(brightness) { // See notes in setBrightness()
      r = (r * brightness) >> 8;
      g = (g * brightness) >> 8;
      b = (b * brightness) >> 8;
    }
    uint8_t *p;
    if(wOffset == rOffset) { // Is an RGB-type strip
      p = &pixels[n * 3];    // 3 bytes per pixel
    } else {                 // Is a WRGB-type strip
      p = &pixels[n * 4];    // 4 bytes per pixel
      p[wOffset] = 0;        // But only R,G,B passed -- set W to 0
    }
    p[rOffset] = r;          // R,G,B always stored
    p[gOffset] = g;
    p[bOffset] = b;
  }
}

You may want to check out Pololu’s page with similar lights. It has more useful details from the same lower level components.

#5

^ Yea I was going to say that it’s practically impossible to program the different colors for those LEDs with ROBOTC… maybe just get one-color LEDS?

#6

@Team80_Giraffes I tried that, but the problem is that, we are only using one digital port and i believe he is using 2 ports.

#7

Not impossible.

The bigger issue is 60 LED’s @ maximum of 60mA per led. That’s way more current than is available on the digital port output power bus.

#8

Wouldn’t the led strip work if it was 5v and not all 60 leds was used, what if only a few leds were used like 30 leds altogether.

#9