arduino test tool for calibration of analog joypad

analog_joy_calibrator.ino

#include <stdio.h>

#define JOY_X A0
#define JOY_Y A1

void setup() {
  pinMode(JOY_X, INPUT);
  pinMode(JOY_Y, INPUT);

  Serial.begin(38400);
}

void loop() {
  short x, y;
  static short xmin = 512, xmax = 512;
  static short ymax = 512, ymin = 512;
  char s[255];
  
  x = analogRead(JOY_X);
  y = analogRead(JOY_Y);

  xmin = min(x, xmin); xmax = max(x, xmax);
  ymin = min(y, ymin); ymax = max(y, ymax);

  // X: center (min-max)    Y: center (min-max)
  sprintf(s, "X:%4d (%d-%d), Y:%4d (%d-%d)\n",
             x, xmin, xmax, y, ymin, ymax);
  Serial.print(s);
}