I am working on a project using 12v LED strips., and running into a problem... This is my first post here, and from all of my lurking and reading - this seems like an awesome community. Happy to be part of it!
Here is the LED strip Im using (
http://www.jaycar.com.au/productView.asp?ID=SL3954 )
After 5 minutes playing with the included controller, I cut it off and attached the 12v 5amp power supply directly to the strand of LED's, and popped my uno on the data line. I ran Adafruits Neopixels example, and lo and behold they started flashing! After hours of trouble shooting and playing around I have solved a few problems (common ground and whatnot) But I am stuck now.
I am trying to make a block of LED's chase down the strand, but when I run my program it doesnt work, the LED's just kinda randomly light up until the whole strand is lit. I can make it do what I want by rapidly disconnecting and reconnecting the 12v power from the strand, then it works like a charm and the block of light moves down like a treat. This strand has no clock, the 4 pins are
VCC (12)
GND
GND
DIN
Im pretty sure its not code related, but who knows. Here is my code, and some pictures. The code is a hardly modified slimmed down example from AF, I have tried changing to 400mhz - then nothing happens at all.
#include <Adafruit_NeoPixel.h>
#define PIN 6
#define N_LEDS 50
Adafruit_NeoPixel strip = Adafruit_NeoPixel(N_LEDS, PIN, NEO_GRB + NEO_KHZ800);
void setup() {
strip.begin();
strip.show();
}
void loop() {
chase(strip.Color(255, 0, 0)); // blue
//chase(strip.Color(0, 255, 0)); // Green
//chase(strip.Color(0, 0, 255)); // red?
}
static void chase(uint32_t c) {
for(uint16_t i=0; i<strip.numPixels()+4; i++) {
strip.setPixelColor(i , c); // Draw new pixel
strip.setPixelColor(i-4, 0); // Erase pixel a few steps back
delay(50);
strip.show();
delay(20);
}
}
Here are some pics of my very basic setup.


Any idea why it wont chase unless I pulse the power to the strip?
Thanks so much!