Arduino Uno, Adafruit PWM driver TLC5947 and LED strips.

Other Hardware LEDs and Multiplexing
1

Hi!

I'm doing a project where I'm trying to run multiple LED strips (4) through a 24-channel Adafruit PWM driver and Arduino Uno.

I've wired up the driver following these instructions. Connecting to the Arduino | TLC5947 and TLC59711 PWM LED Driver Breakouts | Adafruit Learning System

Then I've attached a single LED strip for testing to the 14, 13 and 12 PINs of the driver, through a breadboard.

Then I've attached a 12V power supply (tried both battery pack and wall socket) to the breadboard to power the LED strip. I run the example code for the LED-driver, but nothing happens. The LED strip remains dead.

I've attached an image of my setup here.

I'm pretty new to this. Any idea why it's not working?

image1 copy.jpg
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2

What sort of LED strip have you got? The one in your photograph looks like an addressable strip and you don't drive those with a PWM signal.

3

DC12V/R/G/B is written on the strip, so normal common anode LED strips.
That board is not made to drive strips.
Leo..

4

Oh-oooh. DC12V / G / R / B is written on the strip, yes.

Any suggestions on how I can solve this? Should I buy new LED-strips or a new driver?

I need the 4 LED-strips to be programmed separately, so that they turn off and on one and one in a loop.

Any help is much appreciated!

5

marteteigen:
Any suggestions on how I can solve this? Should I buy new LED-strips or a new driver?

Depends on the length of the strips, number of LEDs per meter (current draw), and if you want to PWM (dim/change colour) them.
Leo..

6

Depends on the length of the strips, number of LEDs per meter (current draw), and if you want to PWM (dim/change colour) them.

Each strip is 70 cm, and there needs to be four of them. The PWM doesn't need to change the color of them, just be able to turn them on / off individually, in a pattern I can program through the Arduino.

7

just be able to turn them on / off individually,

The individual LEDs or the strips need to be controlled individually?

All you need to do is to use a FET for each colour on each strip and drive the FET with a digital output pin. So that will be 12 output pins.
The circuit is here:- Usage | RGB LED Strips | Adafruit Learning System

8

I agree with Grumpy_Mike. Three logic level mosfets per strip.

It seems to be a low density strip with three RBG LEDs in series, spread over ~15cm (between cut lines).
That means a current draw of 20mA per colour per 15cm.
100mA per colour for the ~70cm.
You might get away with common 500mA transistors (2N2222 etc.) with 470ohm base resistors.
Leo..