Basic data question

Projects Programming
6

So I don't have to Google it, what is max/msp?

It is a modular programing language from Cycling 74. I use it in Ableton Live ( digital audio workstation) to comunicate with hardware.
Im biulding a cotroller with Adafruits Neotrellis led/button boards with a Teensy 4.0 controller board.

To make my question clearer.
I need to send integers from 0 to 600 to teensy. And sending directly the int to serial (in max/msp) I could only do 0-255.

Using a different code, with end marker, and playing around with " atoi" and "itoa" I managed to solve that obstacle.
But since I dont understand the different data types and convertions I have a, hopefully, last and more concrete obstacle.

On max/msp , I convert a number (lets say 512) to asccii, append a 10 (endline) at the end and send it to serial module.

On teensy I think I get an array but I need to use integers and cant do the convertion.

Here the code


const byte numChars = 32;
char receivedChars[numChars];          
boolean newData = false; 
unsigned long  a; 


void loop() {
 recvWithEndMarker();
 showNewData();
}

void recvWithEndMarker() {
 static byte ndx = 0;
 char endMarker = '\n';
 char rc;
 
           while (Serial.available() > 0 && newData == false) {
 rc = Serial.read();

 if (rc != endMarker) {
 receivedChars[ndx] = rc;
 ndx++;
 if (ndx >= numChars) {
 ndx = numChars - 1;
 }
 }
 else {
 receivedChars[ndx] = '\0'; 
 ndx = 0;
 newData = true;
 }
 }
}

void showNewData() {
 if (newData == true) {
       
    if (receivedChars == 512 ) {
       a =  0x000000;     
    }

    else if (receivedChars == 513 ) {  
       a =  0x006600;
    }

    else if (receivedChars == 514 ) {
    trellis.show();
    }
 
    else {
    trellis.setPixelColor(receivedChars , a);     
    } 
  newData = false;
  }
}

Here is the error I get

Nuevito: In function 'void showNewData()':
C:\Users\Moris\Desktop\Nuevito\Nuevito.ino:104:26: warning: ISO C++ forbids comparison between pointer and integer [-fpermissive]
     if (receivedChars == 512 ) {
                          ^
C:\Users\Moris\Desktop\Nuevito\Nuevito.ino:108:31: warning: ISO C++ forbids comparison between pointer and integer [-fpermissive]
     else if (receivedChars == 513 ) {  
                               ^
C:\Users\Moris\Desktop\Nuevito\Nuevito.ino:112:31: warning: ISO C++ forbids comparison between pointer and integer [-fpermissive]
     else if (receivedChars == 514 ) {
                               ^
C:\Users\Moris\Desktop\Nuevito\Nuevito.ino:117:44: warning: invalid conversion from 'char*' to 'uint16_t {aka short unsigned int}' [-fpermissive]
     trellis.setPixelColor(receivedChars , a);     
                                            ^
In file included from C:\Users\Moris\Desktop\Nuevito\Nuevito.ino:1:0:
C:\Users\Moris\Documents\Arduino\libraries\Adafruit_seesaw_Library/Adafruit_NeoTrellis.h:82:8: note:   initializing argument 1 of 'void Adafruit_MultiTrellis::setPixelColor(uint16_t, uint32_t)'
   void setPixelColor(uint16_t num, uint32_t color);
        ^