trouble getting my Serial read Character array to compare to another array

Projects Programming
1

I've been working on a module to control my car over bluetooth, but I'm having trouble getting the Serial read input to.
I attached my code below, but here's a copy of my void loop and the variable declaration.

char character[100];
char rgb[][100] = {"Horn", "Remote Start", "Headlights", "Accessory", "Trunk", "Open sunroof", "Close sunroof",
                   "Dwindow up", "Dwindow down", "Pwindow up", "Pwindow down", "Lock",
                   "Unlock", "all lights", "Fades", "Strobe", "Halos", "Underbody Lights",
                   "Interior Lights"
                  };

 if (Serial.available() > 0) {
    while (Serial.available()) {
      delay(20);
      character[t] = Serial.read();
      ++t;
      //red = Serial.parseInt();
      //green = Serial.parseInt();
      //blue = Serial.parseInt();
    }
    character[t] = '\0';
    Serial.println(character);
    for (i = 0; i < 19; i++) {
      Serial.println(rgb[i]);
      Serial.println(character);
      int result = strcmp(character, rgb[i]);
      if (result == 0) {
        BCM(i);
        break;
      } else {
        Serial.println("String's don't match");
      }
    }
  }

Can someone help me figure out whats wrong with my code? It always skips to the else line after it compares the char array.

sketch_may01a.ino (13 KB)

2

It goes to the else part because the 2 strings are not matched.

The way you handle the incoming data is not correct. You are saying that: "Is there a piece of data available? If yes, read the whole thing". But what you should really do is: "is there data available? If yes, read that data and store it. Have I read a complete command? If yes, compare the command to derive it's meaning"

The stick post: read from serial input will be helpful to check out.

3

You need to reset t=0 before you read each new string. You should have seen that Serial.println(character) is showing a previous entry as well as the current one.

if (Serial.available() > 0) {
    t=0;//add this line to reset index
    while (Serial.available()) {
      delay(20);
      character[t] = Serial.read();
      ++t;
      //red = Serial.parseInt();
      //green = Serial.parseInt();
      //blue = Serial.parseInt();
    }
    character[t] = '\0';
    Serial.println(character);
    for (i = 0; i < 19; i++) {
      Serial.println(rgb[i]);
      Serial.println(character);
      int result = strcmp(character, rgb[i]);
      if (result == 0) {
        BCM(i);
        break;
      } else {
        Serial.println("String's don't match");
      }
    }
  }
4

Have a look at the examples in Serial Input Basics - simple reliable ways to receive data.

When the complete message has been received the variable newData will be true and that is the time to do the comparisons.

...R

5

Thank you all for your inputs. I followed your suggestions and got my code up my Serial input working great now.

6 
char rgb[][100] = {"Horn", "Remote Start", "Headlights", "Accessory", "Trunk", "Open sunroof", "Close sunroof",

"Dwindow up", "Dwindow down", "Pwindow up", "Pwindow down", "Lock",
                  "Unlock", "all lights", "Fades", "Strobe", "Halos", "Underbody Lights",
                  "Interior Lights"
                  };

That is 19 strings times 100 bytes; out of curiosity, which Arduino are you using?

This would be a far more efficient approach (saves around 1600 bytes of RAM).

char *rgb[] =
{ "Horn", "Remote Start", "Headlights", "Accessory", "Trunk", "Open sunroof", "Close sunroof",
  "Dwindow up", "Dwindow down", "Pwindow up", "Pwindow down", "Lock",
  "Unlock", "all lights", "Fades", "Strobe", "Halos", "Underbody Lights",
  "Interior Lights"
};

And you can consider to move it to flash (PROGMEM) if needed.