arduino test for zero adjust

analogRead_zero_adjust.ino

#include <stdio.h>

#define JOY_L_X A0
#define JOY_L_Y A1
#define ZERO_THRESH  10
#define MAX 490

void setup() {
  pinMode(JOY_L_X, INPUT);
  pinMode(JOY_L_Y, INPUT);

  Serial.begin(38400);
}

short zero_adjust(short v)
{
  short v_abs, sign;
  
  v_abs = abs(v);
  sign = (v < 0)? -1:1;
  
  if(v_abs > MAX) return MAX * sign;

  if(v_abs < ZERO_THRESH) return 0;   

  return (v_abs - ZERO_THRESH) * sign;
}

void loop() {
  static short lx = 0;
  static short ly = 0;
  char s[255];
  
  lx = lx * 0.9 + zero_adjust(analogRead(JOY_L_X) - 512) * 0.1;
  ly = ly * 0.9 + zero_adjust(analogRead(JOY_L_Y) - 512) * 0.1;

  sprintf(s, "X:%4d    Y:%4d\n", lx, ly);
  Serial.print(s);
}