Python COM PORT tester Arduino tester

// Test program for the Python code at https://pastebin.com/dxCjCSn7
// by Ido Gendel, 2020

// Upload this to an Arduino Uno, close the IDE,
// and connect to the arduino's COM PORT using the Python program.
// If everything works it will blink slowly,
// otherwise it will blink fast.

void setup() {
  pinMode(13, OUTPUT);
  Serial.begin(115200);
}

uint8_t LEDState = 0;

void loop() {

  uint8_t x;
  int16_t y;

  x = random(256);
  Serial.write(x);
  digitalWrite(13, LEDState);
  delay(100);
  y = Serial.read();
  x += 1;
  delay((y != -1) && (uint8_t(y) == x) ? 900 : 0);
  LEDState = 1 - LEDState;

}