Control Digital LED Strip by Power LED

Hey Guys,

I just bought the PowerLED F10-RGBD-12-48-20-FP Digital LED Strip from RS online and am currently trying to control these LED strips with an Arduino Mega.

My goal is to just create a digital “LED Chase pattern” on these guys. I have worked with different LED strips before, but I haven’t used the Power LED ones before.

Does anyone of you know those LEDs? I tried to google my a** off, but couldn’t find anything.
They got a 4 pin connection (12V, Data, Clock, GND), but I couldn’t find anything on the chip soldered on.
The chip says:
“D7722A
1640AT”

Does anyone know these LEDs and even worked with them before? Or can someone help me with finding anything on them?

Thank you guys so much!

Tobi

With two data pins it looks like it is a APA102C like protocol.

I would try the fastLED libiary and try swapping the clock and data over until you get them right. Make sure the ground from the 12V power supply is connected to the ground of the Arduino.

Hi Mike, Thanks for your response!

In the meanwhile i tried using the Adafruit LPD8806 library and tried exactly what you suggested.

When I first plugged them in, everything looked promising. They were not lighting up the right pattern, but the started flashing. However, I forgot to connect both Grounds with each other.

Now I tried it again (also using the fastLED library), and nothing happens, the LEDs don't even start flashing.

I measured all LEDs, they are still fine. Do you think, that by not connecting the grounds I might have killed the chips on the LED strip? Is there any possibility to test, if the chips are still alive?

EDIT: My power supply is a 8,5A 12VDC Power supply. The datasheet for the LEDs stats: Power Consumption: 11,2W. I assumed this is per meter - I got 5 meters. This should do the job, shouldn't it?

Thanks a lot!

Tobi

This should do the job, shouldn’t it?

Yes
That strip says it has 48 LEDs per meter, so 5 meters gives you 48 times 5 = 240 LEDs. Each LED can take 60mA at full brightness white to the maximum current draw is 14.4 A.
However, that strip can only control three LEDs at a time so that means that three LEDs are wired in series. Therefore the current comes down to 14.4 / 3 = 4.8A.

I measured all LEDs, they are still fine.

What do you mean by measured?

They were not lighting up the right pattern, but the started flashing.

This can happen because the missing ground messes up the signal and you could have any old rubbish on the line.

Do you think, that by not connecting the grounds I might have killed the chips on the LED strip?

If the missing ground has burned out an LED it is only likely to be the first one. A drastic thing you could try is to cut off the first LED and wire into the second, but hold off on doing that just yet. It is more likely something else is wrong.

Did you have the series resistor in on the two data signal lines? Did you have the large capacitor across the supply?

Is there any possibility to test, if the chips are still alive?

Not a simple test no. The proper way is to look at the signals on an oscilloscope to verify it is being driven correctly and then if their is still no lighting you could conclude they don’t work.

Grumpy_Mike: What do you mean by measured?

Used a multimeter, and also brought them to light by the 3.3V output of the Arduino. So they work fine

Grumpy_Mike: Did you have the series resistor in on the two data signal lines? Did you have the large capacitor across the supply?

I have 200 Ohm per data line in series. That should be enough I guess? But no Capacitor. Do you think it is necessary? As an Update: I've cut the first 2 LED segments off and run them standalone now. Now the second segment (2nd 3 LEDs) shine continuously green. But still the Arduino is not coming through.

But no Capacitor. Do you think it is necessary?

Yes even more important than the resistor.

I've cut the first 2 LED segments off and run them standalone now.

So does that mean they are controllable from the Arduino? And you can change the colour of them and everything? If so that could point to a power problem.

Grumpy_Mike:
Yes even more important than the resistor.

Ok, I will get one for that purpose. Thank you :slight_smile:

Grumpy_Mike:
So does that mean they are controllable from the Arduino? And you can change the colour of them and everything?
If so that could point to a power problem.

No, sadly not. The green lights come up with just the power supply plugged in.
Once I connect the Arduino, nothing changes.

I’m trying to run the Blink example by FastLED on an Arduino Mega:

#include "FastLED.h"

#define NUM_LEDS 1

#define DATA_PIN 3
#define CLOCK_PIN 13

CRGB leds[NUM_LEDS];

void setup() { 
FastLED.addLeds<APA102, DATA_PIN, CLOCK_PIN, RGB>(leds, NUM_LEDS);
}

void loop() { 
  // Turn the LED on, then pause
  leds[0] = CRGB::Red;
  FastLED.show();
  delay(500);
  // Now turn the LED off, then pause
  leds[0] = CRGB::Black;
  FastLED.show();
  delay(500);
}

Somehow the Arduino is not able to speak to the Stripe. Can I change the clock speed for FastLED somehow? And also, is there a way to estimate the clock speed?

EDIT: I found the DATA_RATE_MHZ() specification for the setup of the LED strip. I played a bit around with the MHz. The LED strip didnt react.

Thank you a lot!
Tobi

The green lights come up with just the power supply plugged in.

That is no indication of anything at all, electronics can come up in any state.

And also, is there a way to estimate the clock speed?

Their is no need to have a precise timing as the data and clock control the data transfer, it is all just in the sequence of edges of the signals, changing the speed should have no effect at all.

Post a good picture of your wiring so we can trace the signals, here is how to post here:- image guide

Grumpy_Mike:
Post a good picture of your wiring so we can trace the signals, here is how to post here:-

Ok, here you go :slight_smile:

The two 1kOhm resistors are against ground for the Data and the Clock pin. Just in case this might be a bit hard to see.

The Capacitor is still missing, I haven't got one yet. I will go for around 1000 uF. You think that might be enough? Or too big?

I will go for around 1000 uF. You think that might be enough?

Yes should be fine.

The two 1kOhm resistors are against ground for the Data and the Clock pin.

Why, what do you think they are doing. You should remove them.

Grumpy_Mike:
Why, what do you think they are doing. You should remove them.

To get the data and clock outputs on the same ground as the Arduino and the power supply.
Anyway, unplugging them didnt change anything.

I also tried all the other FastLED setups. Doesn't change a thing. Maybe I just bought the most shitty LEDs available? :smiley:

Also for the Capacitor: It seems like there already is a capacitor on the stripe:

Do you think I need an aditional one to that?

To get the data and clock outputs on the same ground as the Arduino and the power supply.

That is not the way to do it. You must connect the ground of the power supply to the ground of the LED strip and the ground of the Arduino. You can not use the breadboard to connect the ground of the power supply to the ground of the LED strip because the breadboard can not handle the current. Why is the label saying ground of the Raspberry Pi? You made no reference to the Pi before, what is going on?

The label saying "clock pin 3" is not going to pin 3.

A better picture would help, one that shows where all the wires start and end, including your very short strip. You should be able to get away without a large capacitor for that one.

You are connecting the Arduino's outputs to the blunt end of the arrow?

Also for the Capacitor: It seems like there already is a capacitor on the stripe: Do you think I need an aditional one to that?

Yes it is, the capacitor on the strip is a small ceramic for high frequency decoupling the large capacitor is known as bulk decoupling and handles the low frequency decoupling. Read this:- http://www.thebox.myzen.co.uk/Tutorial/De-coupling.html

Grumpy_Mike: That is not the way to do it. You must connect the ground of the power supply to the ground of the LED strip and the ground of the Arduino. You can not use the breadboard to connect the ground of the power supply to the ground of the LED strip because the breadboard can not handle the current.

I have the power ground also connected directly to the stripe. So there shouldnt bet the full amps running over there. I have tried tried the direct ground connection too, was the same result

Grumpy_Mike: Why is the label saying ground of the Raspberry Pi? You made no reference to the Pi before, what is going on?

The label saying "clock pin 3" is not going to pin 3.

Thats a typo. The clock Pin is pin "13" and the RasPi obviously should be the Arduino ground. I was talking about RasPis all day. My mind tricked me :D

Grumpy_Mike: You are connecting the Arduino's outputs to the blunt end of the arrow?

Do you mean the pin outputs? They start from pin 3 / 13 and pass the breadboard on to the LED strip. Does that answer the question?

Grumpy_Mike: You are connecting the Arduino's outputs to the blunt end of the arrow? Yes it is, the capacitor on the strip is a small ceramic for high frequency decoupling the large capacitor is known as bulk decoupling and handles the low frequency decoupling. Read this:- http://www.thebox.myzen.co.uk/Tutorial/De-coupling.html

Ok. Thank you, very good to know :)

Do you mean the pin outputs?

No, I mean to the strip. There are two ends to the strip, attach the wires so the signals flow down the strip according to the direction of the arrows on the strip, like this:-

Capacitor.PNG

Hey guys,

So I finally gave up on these stripes. I ordered WS2811 from Amazon, and they work without any issue. Maybe I will spend some more tome on these later on, but for now I will just go with this WS2811.

I used the same wiring as with the Power LED one and the FastLED library. Thank you btw for that library Mike, its amazing! And thank you very much for trying to help me! I really appreciate that. I will let you know, if or when I get the PowerLED ones working.

Best Tobi

optimatech: Would it be possible without using a capacitor?

Why do you not want to use a capacitor? You might get something to function but it will never be right and might fail prematurely. Why do you think a capacitor is advised in the first place, are you suffering under the delusion that engineers like to add unnecessary components? No we do it so that under all circumstances it will work and cause no damage. If you see some idiot not using a capacitor he will probably say "but it works for me". Well bully for him in his ignorance because it will not work for everybody, and the more LEDs their are the less likely it is to work for many people. The "not working for everyone" is due to the dynamic characteristics of the power supply used.

So YES use a frigging capacitor.