Help with One-Way Serial Communication via Inductive Coupling

Using Arduino Programming Questions
#1

I am currently working on a project that involves transmitting data wirelessly through inductive coupling. I've attached the schematics below.

Not included in the schematics is a 10k pulldown resistor from the 3.3V voltage regulator on the receiving circuit.

I've also attached a picture showing the waveform from the voltage regulator. This shows that the carrier wave is demodulated... I just need a receiving program that can read the message being sent.

If I've left anything out, feel free to ask!

Receiving Circuit:

Transmitting Circuit:

Receiving Waveform:

Transmitting Program:

void setup() {
Serial.begin(300);
}

void loop() {
Serial.print("Hello world!");
}

#2

Have receive processor’s Tx pin connected to PC via FTDI Basic or equivalent set at 9600, with receive circuit connected to processor’s Rx pin.
This could work I think:

byte x = 0;
byte y = 0;
void setup(){
  Serial.begin(300);
}
void loop(){
  if (Serial.available()>0){
    byte dataArray[x] = Serial.read();
    if (dataArray[x-1] =="!"){
      Serial.begin(9600);
      for (y=0; y<x; y=y+1){
        Serial.print ([dataArray[y]);
      }
      Serial.println("");
      Serial.begin(300);
      x=0;
    }
    x=x+1;
  }
}
#3

CrossRoads:
Have receive processor’s Tx pin connected to PC via FTDI Basic or equivalent set at 9600, with receive circuit connected to processor’s Rx pin.
This could work I think:

byte x = 0;

byte y = 0;
void setup(){
  Serial.begin(300);
}
void loop(){
  if (Serial.available()>0){
    byte dataArray = Serial.read();
    if (dataArray[x-1] =="!"){
      Serial.begin(9600);
      for (y=0; y<x; y=y+1){
        Serial.print ([dataArray[y]);
      }
      Serial.println("");
      Serial.begin(300);
      x=0;
    }
    x=x+1;
  }
}

There seems to be an error in compiling the program, I’ve pasted the log below.

TestSerial.ino: In function ‘void loop()’:
TestSerial.ino:9:37: error: variable-sized object ‘dataArray’ may not be initialized
TestSerial.ino:10:26: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
TestSerial.ino:13:33: error: expected ‘,’ before ‘[’ token
TestSerial.ino:13:33: error: expected identifier before ‘[’ token
TestSerial.ino:13:37: error: expected ‘]’ before ‘;’ token
TestSerial.ino: In lambda function:
TestSerial.ino:13:37: error: expected ‘{’ before ‘;’ token
TestSerial.ino: In function ‘void loop()’:
TestSerial.ino:13:37: error: expected ‘)’ before ‘;’ token
Error compiling.

#4

Okay, maybe a little tweaking needed.

byte x = 0;
byte y = 0;
char dataArray[20];
void setup(){
  Serial.begin(300);
}
void loop(){
  if (Serial.available()>0){
    dataArray[x] = Serial.read();
    if (dataArray[x-1] =='!'){
      Serial.begin(9600);
      for (y=0; y<x; y=y+1){
        Serial.print (dataArray[y]);
      }
      Serial.println("");
      Serial.begin(300);
      x=0;
    }
    x=x+1;
  }
}
#5

This compiles also:

byte dataArray[20];

#6

The examples in Serial Input Basics may be useful.

...R

#7