RGB Led - mixing colors using analogWrite

Question

Currently I'm controlling an RGB LED with my Arduino Nano.

I'm mixing the colors using analogWrite

Though, the LED's don't light up at all for low analogwrite values and the difference between the levels is not visible (to me).

I'm using 100 Ohms resistors between the LED's, using a 680Ohms didn't seem to make a difference.

Analogwrite is working by toggling the LED's fast (PWM)? So not by lowering voltage? This is why I think it's weird that they don't light up at all, on low write values.

My sketch below:

#include <SoftwareSerial.h>

int r, g, b = 0;
String command = "";
const byte rxPin = 11;
const byte txPin = 10;

SoftwareSerial blueTooth (rxPin, txPin);

void handleCommand() {
  r = rgbFromCommand("r=",";");
  g = rgbFromCommand("g=",";");
  b = rgbFromCommand("b=",";");

  if(r != -1){
    analogWrite(A2,r);
  }
  if(g != -1){
    analogWrite(A1,g);
  }
  if(b != -1){
    analogWrite(A0,b);
  }
}

int rgbFromCommand(String prefix, String postfix) {
  int idx = command.indexOf(prefix);
  int endIdx = command.indexOf(postfix,idx);
  if(idx>=0 && endIdx>=0){
    idx+=2;
    return command.substring(idx,endIdx).toInt();
  }
  return -1;
}


void setup() {
  pinMode(rxPin,INPUT);
  pinMode(txPin,OUTPUT);
  Serial.begin(9600);
  blueTooth.begin(9600);
}

void loop() {
  if (Serial.available() > 0) {
    // read the incoming byte:
    char incomingByte = Serial.read();

    if(incomingByte == '\n'){
      handleCommand();
      command = "";
    }else{
      command += incomingByte;
    }
  }
  if(blueTooth.available() > 0){
        // read the incoming byte:
    char incomingByte = blueTooth.read();

    if(incomingByte == '\n'){
      handleCommand();
      command = "";
    }else{
      command += incomingByte;
    }
  }
}

Answer 1

Analog pins aren't PWM pins. Instead you have to use the pins marked with a ~

Pins that aren't PWM pins will be off with a value of 0-127 and on with a value between 128 and 255.