if (UART1_SR_TXE==1)
{
   if (i == array_length)
   {
      // передача завершена
   }
   else
   {
      UART1_DR = res[i++];
   }
}

/*
  AnalogReadSerial

  Reads an analog input on pin 0, prints the result to the Serial Monitor.
  Graphical representation is available using Serial Plotter (Tools > Serial Plotter menu).
  Attach the center pin of a potentiometer to pin A0, and the outside pins to +5V and ground.

  This example code is in the public domain.

  https://www.arduino.cc/en/Tutorial/BuiltInExamples/AnalogReadSerial
*/

// the setup routine runs once when you press reset:
void setup() {
  // initialize serial communication at 9600 bits per second:
  Serial.begin(9600);
}

// the loop routine runs over and over again forever:
void loop() {
  // read the input on analog pin 0:
  int sensorValue = analogRead(A3);
  // print out the value you read:
  Serial.println(sensorValue);
  delay(1);        // delay in between reads for stability
}

#include "Arduino.h"
#include "Serial.h"

// RX (D15) -> TX
// TX (D14) -> RX
// A0 - analog input

void setup(void) {
  Serial_begin(9600);
}

void loop (void) {
  Serial_print_u(analogRead(PIN_A0));
  Serial_println();

  delay(200);
}