For loop trigger for tlc5940

Using Arduino Programming Questions
#1

Hi everyone,
I’ve been playing with tlc5940 and trying to understand how to write software for it.
I’m trying to use for loop to fade leds.
For testing I did the following loop

#include "Tlc5940.h"
#include "tlc_fades.h"

void setup()
{

  Tlc.init(4095);
  Serial.begin(9600);

}

void loop()
{
  int start = 0;
  int finish = 1000;
  for (int led=0; led < 7; led++)
  {
    tlc_addFade(led ,0, 4095, start, finish);
    start = start + 200;
    finish = finish + start;
  }

   tlc_updateFades();
}

This works as expected and fades leds

No I want o start fading leds on trigger so I put the same loop into if condition

#include "Tlc5940.h"
#include "tlc_fades.h"

  int val = 1000;
  int go = 0;

void setup()
{
  Tlc.init(4095);
  Serial.begin(9600);
}
void loop()
{

  val=analogRead(0);
  Serial.println(val,DEC);
  delay(500);

  if (val <= 600 && go == 0 )
  {
    go = 1;
    int start = 0;
    int finish = 1000;
    for (int led=0; led < 7; led++)
    {
      tlc_addFade(led ,4095, 0, start, finish);
      start = start + 200;
      finish = finish + start;
    }
    tlc_updateFades();
  }
}

Now instead fading the leds just light up.
What am I doing wrong?

Thank you

#2

What am I doing wrong?

Probably this:

if (val <= 600 && go == 0 )
  {
    go = 1;
#3

Just a guess, but try moving tlc_updateFades() out of the if statement so it runs every time

#4 
    start = start + 200;
    finish = finish + start;

You might want to look at the compound operators, so you can at least look like a smart C coder:

    start += 200;
    finish += start;
#5

AWOL:

What am I doing wrong?

Probably this:

if (val <= 600 && go == 0 )

{
    go = 1;

Not sure what is wrong here I change go to 1 because I want it to run once.

PaulS:

    start = start + 200;

finish = finish + start;



You might want to look at the compound operators, so you can at least look like a smart C coder:

start += 200;
    finish += start;

Thanks for the tip I’m not a coder so still learning :slight_smile:

wildbill:
Just a guess, but try moving tlc_updateFades() out of the if statement so it runs every time

I don’t need it to run every time.

#6