c – arduino计数是否有限制以及如何解决？

出于某种原因,我的计数器不会超过8米或31991编码器脉冲.一旦达到这个8米的限制,该数字变为负数并开始向后计数,如-7.9> -7.8(即继续向上计数到0).
然后它达到零并再次计入8 ……

这对我来说很奇怪,而我有限的编码知识也无法修复它.

有谁知道如何解决这个或我能做些什么来使它工作？

#include <LiquidCrystal.h>

#define inputA_in 6
#define inputB_in 7

LiquidCrystal lcd(12,11,5,4,3,2);

int inputA_V = 0;
int inputB_V = 0;
int inputA = 0;
int inputB = 0;
int counter = 0;
// smeni vrednost tuka pred run 
int console_frequency_milliseconds = 200; /// edna sekunda


int aLastState = 0;
int bLastState = 0;
float meters = 0.0;
unsigned long lasttime = 0;

int move_positive = 0;
int move_negative = 0; 

  int maximum_input_digital_v = 300;   //treba da citash od konzola i da gi setirash max i min
  int minimum_input_digital_v = 0;
  int logical_threshold_v = 150;       //brojkive se random staveni

void setup() {

  pinMode (inputA_in,INPUT);
  pinMode (inputB_in,INPUT);

  Serial.begin (9600);

  lcd.begin(16,2);
  // Print a message to the LCD
  lcd.print("Metraza [m]");

  aLastState = inputA;
  bLastState = inputB;
  lasttime = 0;
}

void loop () {

  inputA = digitalRead(inputA_in);

  if (inputA != aLastState) {
    if (digitalRead(inputB_in) != inputA) {
      counter ++;
      aLastState = inputA;
    } else {
      counter --;
       aLastState = inputA;
    }
  }
   if (millis() - console_frequency_milliseconds > lasttime)//Detect once every 150ms
  {
    meters = 0.50014 * counter / 2000;
    Serial.print("Position: ");
    Serial.println(meters);
       lasttime = millis();

  lcd.setCursor(0,1);
  //Print a message to second line of LCD
  lcd.print(meters);
  }

}