USI and neopixel not working in Gemma

[inventor]

Hi

I'm trying to use this library to recommend this post

http://www.adafruit.com/blog/2013/09/30 ... e-trinket/

USI or neopixel work well separately, but not in set, neopixel not working with USI active

Help

Thanks

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[egutting]

It looks like the USI runs off of pins 0 & 1, do you have the neo pixels on one of those pins as well?

[inventor]

I have Neopixel in D2

[egutting]

Could you post the code you are using with the </> button to see if there may be something there?

[inventor]

Yes, i have a Gemma working 8Mhz :)

Code: Select all

/* UsiSerial by [email protected]
 *  
 * UsiSerial is a simple wrapper around the code from AVR307 so that Arduino can use USI to implement a hardware serial port
 *
 * This is a simple echo example.
 *
 * The USI class works almost exactly like HardwareSerial
 * So you can use print and println and other functions like that
 *
 * PORTB0 is DI, thus it is RX
 * PORTB1 is DO, thus it is TX
 * default baud rate is 19200, which can only be changed in USI_UART_config.h
 * only some baud rates will work, depending on CPU frequency
 * buffers are small to save memory, since this library is designed for ATtiny
 * testing was done using a 16 MHz Trinket
 *
 * Important note: requires Timer1 and PCINT to be occupied
 

#include <UsiSerial.h>
#include <Adafruit_NeoPixel.h>

#define PIN 2 //marked D2 on GEMMA

// Parameter 1 = number of pixels in strip
// Parameter 2 = pin number (most are valid)
// Parameter 3 = pixel type flags, add together as needed:
//   NEO_KHZ800  800 KHz bitstream (most NeoPixel products w/WS2812 LEDs)
//   NEO_GRB     Pixels are wired for GRB bitstream (most NeoPixel products)

Adafruit_NeoPixel strip = Adafruit_NeoPixel(48, PIN, NEO_GRB + NEO_KHZ800);

int sine[] = {4, 3, 2, 1, 0, 15, 14, 13, 12, 20, 21, 22, 23, 24, 25, 26, 27, 28, 36, 35, 34, 33, 32, 47, 46, 45, 44}; //these are the pixels in order of animation-- 27 pixels in total

void setup()
{
  UsiSerial.begin();
  
  strip.begin();
  strip.setBrightness(40); //adjust brightness here
  strip.show(); // Initialize all pixels to 'off'
}

void loop()
{

  for(int i=0; i<36; i++) { 
    strip.setPixelColor(sine[i], strip.Color(75, 250, 100)); //change RGB color value here
    delay(40);
    for (int j=0; j<25; j++){
      strip.setPixelColor(sine[(j+i+4)%36], strip.Color(0, 0, 0));
    }
    strip.show(); 
  }

  if (UsiSerial.available() > 0) {
    UsiSerial.write(UsiSerial.read());
  }  
}

Thanks

[egutting]

This may be the issue...in the NeoPixel library it turns off interrupts: Line 97 of Adafruit_NeoPIxel.cpp: noInterrupts(); // Need 100% focus on instruction timing
The hardware serial mentions in the read_me file: Important note: requires Timer1 and PCINT to be occupied.

You need interrupts for the hardware serial to work, but need them turned off for NeoPixels due to the timing.

[inventor]

Then they would not work together? or there would be a solution?

Thank you for your help

[adafruit_support_bill]

You would not be able to use them at the same time. Neopixel updates and interrupts are fundamentally incompatible.