Neopixel pi pico not working

Projects General Guidance
1

with this code my first pixel firs goes white. and then the second pixel goes green with the firs going cream colored. Why is this happening?

// NeoPixel Ring simple sketch (c) 2013 Shae Erisson
// Released under the GPLv3 license to match the rest of the
// Adafruit NeoPixel library

#include <Adafruit_NeoPixel.h>
#ifdef __AVR__
 #include <avr/power.h> // Required for 16 MHz Adafruit Trinket
#endif

// Which pin on the Arduino is connected to the NeoPixels?
#define PIN        1 // On Trinket or Gemma, suggest changing this to 1

// How many NeoPixels are attached to the Arduino?
#define NUMPIXELS 2 // Popular NeoPixel ring size

// When setting up the NeoPixel library, we tell it how many pixels,
// and which pin to use to send signals. Note that for older NeoPixel
// strips you might need to change the third parameter -- see the
// strandtest example for more information on possible values.
Adafruit_NeoPixel pixels(NUMPIXELS, PIN, NEO_GRB + NEO_KHZ800);

#define DELAYVAL 500 // Time (in milliseconds) to pause between pixels

void setup() {
  // These lines are specifically to support the Adafruit Trinket 5V 16 MHz.
  // Any other board, you can remove this part (but no harm leaving it):
#if defined(__AVR_ATtiny85__) && (F_CPU == 16000000)
  clock_prescale_set(clock_div_1);
#endif
  // END of Trinket-specific code.

  pixels.begin(); // INITIALIZE NeoPixel strip object (REQUIRED)
}

void loop() {
pixels.setPixelColor(1, 255, 255, 255, 255);
pixels.show();
delay(1000);
pixels.clear();
pixels.setPixelColor(0, 255, 255, 255, 255);
pixels.show();
delay(1000);
pixels.clear();
}

i am using the earlephilhower pi pico core. my pixels are RGBW

Untitled drawing (1)
Untitled drawing (1)960×720 171 KB

2

Is the last parameter for RGBW neopixel? Normally, only PIX, RED, GRN, BLU are the parameters.. Change pixel numbers and see if the problem folliws.

3

Tell the sketch that. This is wrong:

Adafruit_NeoPixel pixels(NUMPIXELS, PIN, NEO_GRB + NEO_KHZ800);

a7

4

@alto777 where would i put this?

5

This in the object definition

NEO_GRB

says you have three colour pixels and the order is green, red and blue.

There are enough constants like that to cover the ways pixels can be outfitted and ordered.

You have some variation of RGBW four different LEDs. Recall or learn that four things can be placed in 24 different orders, so pick one

#define NEO_WRGB ((0 << 6) | (1 << 4) | (2 << 2) | (3)) ///< Transmit as W,R,G,B
#define NEO_WRBG ((0 << 6) | (1 << 4) | (3 << 2) | (2)) ///< Transmit as W,R,B,G
#define NEO_WGRB ((0 << 6) | (2 << 4) | (1 << 2) | (3)) ///< Transmit as W,G,R,B
#define NEO_WGBR ((0 << 6) | (3 << 4) | (1 << 2) | (2)) ///< Transmit as W,G,B,R
#define NEO_WBRG ((0 << 6) | (2 << 4) | (3 << 2) | (1)) ///< Transmit as W,B,R,G
#define NEO_WBGR ((0 << 6) | (3 << 4) | (2 << 2) | (1)) ///< Transmit as W,B,G,R

#define NEO_RWGB ((1 << 6) | (0 << 4) | (2 << 2) | (3)) ///< Transmit as R,W,G,B
#define NEO_RWBG ((1 << 6) | (0 << 4) | (3 << 2) | (2)) ///< Transmit as R,W,B,G
#define NEO_RGWB ((2 << 6) | (0 << 4) | (1 << 2) | (3)) ///< Transmit as R,G,W,B
#define NEO_RGBW ((3 << 6) | (0 << 4) | (1 << 2) | (2)) ///< Transmit as R,G,B,W
#define NEO_RBWG ((2 << 6) | (0 << 4) | (3 << 2) | (1)) ///< Transmit as R,B,W,G
#define NEO_RBGW ((3 << 6) | (0 << 4) | (2 << 2) | (1)) ///< Transmit as R,B,G,W

#define NEO_GWRB ((1 << 6) | (2 << 4) | (0 << 2) | (3)) ///< Transmit as G,W,R,B
#define NEO_GWBR ((1 << 6) | (3 << 4) | (0 << 2) | (2)) ///< Transmit as G,W,B,R
#define NEO_GRWB ((2 << 6) | (1 << 4) | (0 << 2) | (3)) ///< Transmit as G,R,W,B
#define NEO_GRBW ((3 << 6) | (1 << 4) | (0 << 2) | (2)) ///< Transmit as G,R,B,W
#define NEO_GBWR ((2 << 6) | (3 << 4) | (0 << 2) | (1)) ///< Transmit as G,B,W,R
#define NEO_GBRW ((3 << 6) | (2 << 4) | (0 << 2) | (1)) ///< Transmit as G,B,R,W

#define NEO_BWRG ((1 << 6) | (2 << 4) | (3 << 2) | (0)) ///< Transmit as B,W,R,G
#define NEO_BWGR ((1 << 6) | (3 << 4) | (2 << 2) | (0)) ///< Transmit as B,W,G,R
#define NEO_BRWG ((2 << 6) | (1 << 4) | (3 << 2) | (0)) ///< Transmit as B,R,W,G
#define NEO_BRGW ((3 << 6) | (1 << 4) | (2 << 2) | (0)) ///< Transmit as B,R,G,W
#define NEO_BGWR ((2 << 6) | (3 << 4) | (1 << 2) | (0)) ///< Transmit as B,G,W,R
#define NEO_BGRW ((3 << 6) | (2 << 4) | (1 << 2) | (0)) ///< Transmit as B,G,R,W

or get some more info on the exAct strip you using and use the correct one.

DO NOT compensate for "green looks red" and "blue looks green" type errors by changing the colours in your code. DO find the correct constant for your type of pixel. Then all the software can view the strip through the identity the constant gives it and get the colours exact. Change strip type, change the NEO_ constant in the constructor.

Or you can write a simple sketch that makes pixel 0 red, or should, pixel 1 green, pixel 2 blue and pixel 3 white, and sit around all night trying to get the right constant. If green and red are swapped, swap R and G. It's less fun than it sounds like. :expressionless:

HTH

a7

1 Like