Arduino Mega + MW LDD = Should be easy, but no

[JoelATX]

I'm having trouble controlling the LDD drivers with the PWM signal. I have a Mega 2560 R3, Coralux x5 board and Meanwell LDDs installed. When the pin is set to zero I get no voltage out, but when anything greater than zero is set, the voltage is 46.7. Which is what the MW SE-350-48 PS is supplying. If I check the voltage coming from pin 3 it is inline with the the value set.

I read other places that is would be a grounding issue, but I've grounded everything. Ground from Mega to the ground from PS.

Any help or guidance would be VERY helpful.

Here is picture of the setup.

[jaggedfire]

What does your code look like? Grounding has also been my biggest issue in the past.

[jaggedfire]

Are the two 'VSS' lines coming from the same source and same with your GND? What is reading 46.7V?...output of your LDD? Does this have an emitter connected when you are reading? Also, what voltage are you reading on your PWM pin3?

[JoelATX]

Here is the code. I had a bunch of code for a LCD, but it was all commented out and now removed.

/*
Basic PWM controll
*/
// include the library code:
//#include "Wire.h"
//#include "LiquidCrystal.h"
//#include "RTClib.h" // a basic DS1307 library that returns time

int threshold = 15;


int white = 3;           // the pin that the LED is attached to
int whitelv = 1;    // how bright the LED is

int color = 5;           // the pin that the LED is attached to
// int brightness = 0;    // how bright the LED is
int colorlv = 100;    // how bright the LED is

int blue = 9;           // the pin that the LED is attached to
// int brightness = 0;    // how bright the LED is
int bluelv = 0;    // how bright the LED is
int fadeAmount = 5;    // how many points to fade the LED by

int uv = 10;           // the pin that the LED is attached to
int uvlv = 0;    // how bright the LED is


void setup() {
  pinMode(white, OUTPUT);
  pinMode(color, OUTPUT);
  pinMode(blue, OUTPUT);
  pinMode(uv, OUTPUT);
}

void loop() {
    int runtime = (millis()/1000);
  delay(5000);

  analogWrite(white, whitelv);    
  analogWrite(color, colorlv);
  analogWrite(blue, bluelv);
  analogWrite(uv, uvlv);   
}

[JoelATX]

Are the two 'VSS' lines coming from the same source and same with your GND? What is reading 46.7V?...output of your LDD? Does this have an emitter connected when you are reading? Also, what voltage are you reading on your PWM pin3?

The blue(+) and green(-) wires were from the same PS, but are disconnected at the PS. (I realized that its just one power block at the PS, even though it has 3 positive screw connectors)

46.x is from the LDD output.

I have not connected it to a string of LEDs, because I don't have control.

PIN 3 voltage varies with settings, something like; 100 gives about 1.8v, 255 almost the full 5v.

[jaggedfire]

It seems that the mega is writing properly, but you have to have the LDD sinked to a negative terminal for it to function properly. I would disconnect, throw your cheapest emitters (3-4) in a series to test it then retry. If you dont have some you want to risk, I have a 12W you can throw on there for testing. These things are more resilient that most believe.

Here is a simple PT4115 driver sch. For it to 'arc' it relies on the 'negative' loop for feedback to control the voltage supplied. The LDD is similar in function.

Sounds like you're already there with the Mega, just need the LED's

[JoelATX]

Maybe cautious isn't always a good thing.

I strung together 8 small LEDs and a 10K resistor. Set my brightness to 1, 2, 3, 4 on the channels, and I get 14.0, 14.2, 14.6 and 14.8 at each pin. So the LDD just needs to complete a circuit before it will work.

Better to be cautious than blow a RapidLED Aurora puck. But I already miss the 8 hours I've been trying to figure this out.

THANKS!