c언어 처음인가봅니다.
 
if(code=='1' or '2' or '3' or '0'){ 
if문의 조건식에 문제가 있군요
인간의 언어처럼 막 사용하면 컴파일러가 이해하지 못합니다.
if((code>='0')&&(code<='3')){ 
//
  delay(100);
초음파센서의 측정 주기는 수십ms이상 되어야합니다.
 
// MCU BASIC: https://www.basic4mcu.com
// DateTime : 2019-05-28 오후 1:25:20
// by Ok-Hyun Park
현재 pixycam과 초음파 센서를 이용해서 선을 추적해서 따라가다가 초음파 센서로 장애물이 감지가 되면
정지하는 시스템을 구현 중인데 제대로 동작을 하지 않아 질문 드립니다.
현재코드는 아래와 같은데  if(distance<10)이 코드를 넣으면 아예 동작을 안합니다.
if(distance<10)코드를 빼면 제대로 동작을 합니다.
그래서 초음파센서 코드만 실행해 봤는데 정상 작동을 하였습니다.
어디 코드를 어떻게 고쳐야 정상 작동 하나요?ㅠㅠ
//
#include <SPI.h>
#include <Pixy2.h>
#include <TPixy2.h>
#include <Pixy2Line.h>
#define X_CENTER(pixy.frameWidth/2)
Pixy2 pixy;
// Zumo speeds,maximum allowed is 400
#include <ZumoMotors.h>
#define ZUMO_FAST        400
#define ZUMO_SLOW        200
ZumoMotors motors;
//
#include <SoftwareSerial.h>
SoftwareSerial mySerial(2,3);
//
#include <PIDLoop.h>
PIDLoop headingLoop(5000,0,0,false);
//
#define ledPin 5
#define trig 13
#define echo 12
//
char    code,buf[96];
int8_t  res; 
int     left,right; 
int32_t error; 
        long duration;
float   distance;
//
void setup(){
  pinMode(ledPin,OUTPUT); pinMode(trig,OUTPUT); pinMode(echo,OUTPUT);
  motors.setLeftSpeed(0); motors.setRightSpeed(0);
  pixy.init(); pixy.setLamp(1,1); pixy.changeProg("line_tracking"); pixy.setServos(500,1000);
  Serial.begin(115200); Serial.print("Starting...\n");
  mySerial.begin(9600);
}
//
void loop(){
  delay(100);
  digitalWrite(trig,1); delayMicroseconds(10); digitalWrite(trig,0);
  duration=pulseIn(echo,1); distance=duration/58.0;
  //
  if(mySerial.available()){
    code=(mySerial.read());
    if((code>='0')&&(code<='3')){ digitalWrite(ledPin,1); delay(3000); digitalWrite(ledPin,0); }
  }
  //
  if(distance<10){ motors.setLeftSpeed(0); motors.setRightSpeed(0); } //초음파 조건문
  else{
    res=pixy.line.getMainFeatures();
    if(res<=0){ motors.setLeftSpeed(0); motors.setRightSpeed(0); Serial.print("stop "); Serial.println(res); return; }
    //
    if(res&LINE_VECTOR){
      error=(int32_t)pixy.line.vectors->m_x1-(int32_t)X_CENTER; pixy.line.vectors->print();
      headingLoop.update(error);
      left=headingLoop.m_command; right=-headingLoop.m_command;
      //
      if(pixy.line.vectors->m_y0>pixy.line.vectors->m_y1){
        if(pixy.line.vectors->m_flags&LINE_FLAG_INTERSECTION_PRESENT){ left+=ZUMO_SLOW; right+=ZUMO_SLOW; }
        else                                                         { left+=ZUMO_FAST; right+=ZUMO_FAST; }
      }
      else{ left-=ZUMO_SLOW; right-=ZUMO_SLOW; }
      //
      motors.setLeftSpeed(left); motors.setRightSpeed(right);
    }
    //
    if(res&LINE_INTERSECTION){
      if     (code==3){ pixy.line.setNextTurn( 45); pixy.line.intersections->print(); } // blue
      else if(code==2){ pixy.line.setNextTurn(  0); pixy.line.intersections->print(); } // green
      else if(code==1){ pixy.line.setNextTurn(-45); pixy.line.intersections->print(); } // red
      else if(code==0){ motors.setLeftSpeed(0); motors.setRightSpeed(0); Serial.print("stop "); Serial.println(res); return; } // stop
    }
  }
}