Hello, I’m new to FastLED but not new to programming in general.

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1

Hello, I’m new to FastLED but not new to programming in general.
For now I’m trying to make one meter of a 5v strip work with Teensy 2.0.
I’m running very simple code, yet no matter what I do in the code, the first LED flashes white very rapidly.
I have a 30W power supply and two 680 OHM resistors in parallel, equating to 340 OHM between the teensy output and the LED strip input. I’m using FastLED 3.1 with Arduino 1.6.5 on Windows 8.
Any advice would be much appreciated, thanks.

Here is my LED strip: http://www.aliexpress.com/store/product/5m-DC5V-WS2812B-led-pixel-srip-IP68-in-silicon-tube-30pcs-WS2812B-M-with-30pixels-36W/701799_949715127.html

Here is my code:
#include <FastLED.h>
#define NUM_LEDS 30
#define DATA_PIN 6
CRGB leds[NUM_LEDS];
void setup() {
FastLED.addLeds<WS2812B, DATA_PIN>(leds, NUM_LEDS);
}
void loop() {
leds[0] = CRGB::Black;
FastLED.show();
delay(1000);
}

2

Is this your emtire code?

3

Try using one of the example patterns that come with the library… I’d start with the one that checks the RGB order.

4

Is the ground on the LED strip connected to the ground on the teensy? If not try that and see if it helps

5

Yes, I use the pairs in the network cable as data and ground (to the controller), and then supply the power and ground separately. If the LEDs aren’t grounded to the controller you’ll get data timing issues and unexpected results. Also I only use 100ohm resistors with 3.3v controllers…

6

when you say network cable, are you sure you are using the right PIN number? not sure about the Teensy 2.0 but on the new Teensys with the network cable adapter, i beleive the first pin is 7 and not 6.

7

@Noel_Kuck
For now, yes. I’ve been trying out different colors, with no change in the output.

8

@Chaka_September
My ground from the controller and power supply is connected to ground from the teensy.

9

@Jeremy_Spencer
Teensy 2 is 5v…

10

Are you inputting to the correct end of the strip? Check the arrows to make certain that you are connected to the data input of the strip.

11

@Noel_Kuck
Yup, I’m connected to the input side.

12

Try reducing the value of the resistor(s). I’m not familiar with the teensy 2, but you can easily power 30 LEDs from the 5v pin on a nano as long as you don’t run them all on full bright white. Try using the 5v and ground pins on the teensy.

13

I’m powering directly off of teensy now. I’ve taken the resistors out, and I’ve also added another two 680’s in parallel, giving 170OHM. No luck yet. Thanks for your help so far everyone…

14

Have you tried the RGB calibrate example sketch?

15

yep, no luck… I also uninstalled and reinstalled Teensy/Arduino on my computer. Ever since I did that and switched the power I get no output at all on the LEDs, except when i initially plug them in and they all go white for a split second. I’m just wondering if there is some issue with Teensy 2.0 and FastLED, maybe i should just go grab a Teensy 3.2 tomorrow?

16

I think someone already brought this up, but check all connections and that all grounds are interconnected, power supply, strip, and arduino.

17

@Noel_Kuck
Done and done…

18

What version of teensyduino are you using? In theory it should work just as well as a leonardo, after all it’s an atmega32u4 under the hood - but I haven’t fired up a teensy 2 in … years at this point.

19

I’m using Teensyduino 1.25 at the moment… I also tried with 1.22 with similar results

20

Ok, i’ll have to see if I have a 2.0 or a ++2.0 anywhere around here that I can try running a test with - also, for laughs, have you tried pins other than pin 6?