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Thread: struggling to communicate with ws2812

  1. #1

    struggling to communicate with ws2812

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    I'm trying to make an infinity cube with a teensy 3.2 and a ws2812 string. If I use a mega I can light each pixel of the string, using fastLED. I am only able to get the first pixel to light with what I've done with the teensy3.2

    The sketch I'm using on the teensy is:
    Code:
    #include <WS2812Serial.h>
    const int numled = 105;
    const int colorStep = 65536/numled; //several loops would benefit from this constant
    const int led_pin = 10;       //Pin to connect LED ring data in
    byte drawingMemory[numled*3];         //  3 bytes per LED
    DMAMEM byte displayMemory[numled*12]; // 12 bytes per LED
    
    WS2812Serial ring(numled, displayMemory, drawingMemory, led_pin, WS2812_RGB);
    void setup() { 
      ring.begin();
      ring.show(); // Initialize all pixels to 'off'
      ring.setBrightness(84);
      delay(3000);
      Serial.begin(9600);
      pinMode(13,OUTPUT);
    }
    
    void loop() {
      // put your main code here, to run repeatedly:
      static uint32_t c,color = 0x0f0f00;
      // First slide the led in one direction
      for(int i = 0; i < numled; i++) {
       // digitalWrite(13,LOW);
        // Set the i'th led to red 
         ring.setPixelColor(c, 0xff0000 );
         ring.show();
         
         Serial.println(i);
        // Show the leds
         delay(200);
         digitalWrite(13,HIGH);
         delay(200);
        // now that we've shown the leds, reset the i'th led to black
         ring.setPixelColor(c, 0 );
      }
    
    }
    for what it's worth the Mega code is:
    Code:
    #include "FastLED.h"
    
    // How many leds in your strip?
    #define NUM_LEDS 105 
    
    // For led chips like Neopixels, which have a data line, ground, and power, you just
    // need to define DATA_PIN.  For led chipsets that are SPI based (four wires - data, clock,
    // ground, and power), like the LPD8806, define both DATA_PIN and CLOCK_PIN
    #define DATA_PIN 6
    #define CLOCK_PIN 13
    
    // Define the array of leds
    CRGB leds[NUM_LEDS];
    
    void setup() { 
      Serial.begin(57600);
      Serial.println("resetting");
      LEDS.addLeds<WS2812,DATA_PIN,RGB>(leds,NUM_LEDS);
      LEDS.setBrightness(84);
    }
    void fadeall() { for(int i = 0; i < NUM_LEDS; i++) { leds[i].nscale8(250); } }
    
    void loop() { 
      static uint8_t hue = 0;
      //Serial.print("x");
      // First slide the led in one direction
      for(int i = 0; i < NUM_LEDS; i++) {
        // Set the i'th led to red 
        leds[i] = CHSV(hue++, 255, 255);
        // Show the leds
        FastLED.show(); 
        delay(100);
        // now that we've shown the leds, reset the i'th led to black
        leds[i] = CRGB::Black;
      }
    }
    I presume my issue is electrical rather than software. The IC is a SN54AHCT125. On the mega I did not use a capacitor or resistor, just plugged into D6 and 5V and GND directly on the board.

  2. #2
    I think I missed grounding the IC, but just fixed that and no change.

  3. #3
    Senior Member PaulS's Avatar
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    Perhaps you should try the basic WS2812Serial example first to rule out any hardware issues.
    You wiring seems OK, although good engineering practice is to connect unused pins to a defined level instead of leaving them floating.

    Paul

  4. #4
    Senior Member
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    Not familiar with that library, but you appear not to be iterating the LED number: your loop iterates i, but ring.setPixelColor() is using c, which you never touch after defining it...

  5. #5
    Senior Member PaulStoffregen's Avatar
    Join Date
    Nov 2012
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    25,244
    What happens if you try File > Examples > WS2812Serial > BasicTest, of course with the pin number edited to 10. Does that work?

  6. #6
    Thanks. You were right it was software.

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