How to reliably send large strings via serial port to arduino

Question

I'm trying to send a large string to Arduino as constant as possible, But whatever i try it is never reliable, On c# I have:

private void OnTimedEvent(Object myObject, EventArgs myEventArgs)
{
    string start = "0:" + 255 * (l / 100) + ":0;";
    start = string.Concat(Enumerable.Repeat(start, 24));
    start += ".";

    char[] end = start.ToCharArray();
    port.Write(new string(end));
    Invalidate();
}

And on arduino i have:

#include <FTRGBLED.h>
#include <Vect3d.h>

int clockPin = 13;
int dataPin = 11;

Tinker::Vect3d<float> recCol(0,0,0);

RGBLEDChain led(25, clockPin, dataPin);

int count = 0, ledc = 0;

void setup() {
  led.begin();
  Serial.begin(19200);
}

void loop() {
  if(Serial.available() > 0){
    char c = Serial.read();
    if(c == '.')
    {    
      ledc = 0;  
      recCol[0] = 0;
      recCol[1] = 0;
      recCol[2] = 0;
      led.update();
    }
    else
    {
      if(c == ';')
      { 
        FTLEDColour col = { recCol[0] , recCol[1] , recCol[2] };
        led.setLED(ledc, col);
        recCol[0] = 0;
        recCol[1] = 0;
        recCol[2] = 0;
        ledc++;
        count = 0;
      }

      if(c == ':')
      { 
        count++; 
      }
      else 
      {
        switch(count){
          case 0:
            recCol[0] = recCol[0] * 10 + (c - '0');
            break; 
          case 1:
            recCol[1] = recCol[1] * 10 + (c - '0');
            break;
          case 2:
            recCol[2] = recCol[1] * 10 + (c - '0');
            break;
        }
      }
    } 
  }
}

When the string is created fully static in c# all the lights change, When I try to add some non static bits such as the 255 * var, it suddenly only works for the first LED and flashes random colours, not greenfrom 0 - 255.

Answer 1

First of all, have you confirmed the string being sent is as you expect it to be?

I would start by writing it to debug.writeline to verify.

Second, if you use the Arduino terminal and type the string to it, does it respond as expected?