i have problem with using arduino
error sign like this
아두이노:1.8.9 (Windows 10), 보드:"Arduino Pro or Pro Mini, ATmega168 (3.3V, 8 MHz)"
D:\multiwii 자율비해\SensorBoard\SensorBoard.ino: In function 'void loop()':
D:\multiwii 자율비해\SensorBoard\SensorBoard.ino:101:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
the code of void loop
void loop()
{
int duration, distance; //기본 변수 선언
int sum_of_distances = 0;
cli(); //stop interrupts
//Trig 핀으로 10us의 pulse 발생
digitalWrite(trigPin, LOW); //Trig 핀 Low
delayMicroseconds(2); //2us 유지
digitalWrite(trigPin, HIGH); //Trig 핀 High
delayMicroseconds(10); //10us 유지
digitalWrite(trigPin, LOW); //Trig 핀 Low
//Echo 핀으로 들어오는 펄스의 시간 측정
duration = pulseIn(echoPin, HIGH); //pulseIn함수가 호출되고 펄스가 입력될 때까지의 시간. us단위로 값을 리턴.
sei(); //allow interrupts
//음파가 반사된 시간을 거리로 환산
//음파의 속도는 340m/s 이므로 1cm를 이동하는데 약 29us.
//따라서, 음파의 이동거리 = 왕복시간 / 1cm 이동 시간 / 2 이다.
distance = duration / 29 / 2; //센치미터로 환산
if (distance > max_distance) {
distance = max_distance;
}
if (distance < min_distance) {
distance = max_distance;
}
//////filtering sonar error//////////////
sum_of_distances = 0;
for(int i = 0 ; i < sizeof(prev_distances) / sizeof(int) ; i++) {
sum_of_distances = sum_of_distances + prev_distances*;*
- if(i > 0) {*
prev_distances[i-1] = prev_distances*;
_ }_
_ }_
distance = (distance + sum_of_distances) / ((sizeof(prev_distances) / sizeof(int)) + 1);
prev_distances[(sizeof(prev_distances) / sizeof(int)) - 1] = distance;*
* ///////////////////////////////////////////*
* channel1.readSignal();*
* //Serial.print(distance);*
* //Serial.print(" ");*
* //Serial.print(channel1.getSignal());*
* //Serial.print(" ");*
* //Serial.print(sonarFrontDistanceWhileMissionCount);*
* //Serial.println();*
* if(1800 < channel1.getSignal()) {*
* if (GP_FRONT_SONAR_DISTANCE_OF_AVOID_WHILE_MISSION_MIN < distance*
* && distance < GP_FRONT_SONAR_DISTANCE_OF_AVOID_WHILE_MISSION_MAX) {
_ sonarFrontDistanceWhileMissionCount++;_
if(sonarFrontDistanceWhileMissionCount > GP_FRONT_SONAR_AVOID_WHILE_MISSION_COUNT_LIMIT) {
_ ppm[0] = 2300; //2300*_
* }*
* }*
* else {*
* ppm[0] = 1400;*
* sonarFrontDistanceWhileMissionCount = 0;*
* } *
* }*
* else {*
* ppm[0] = 1400; *
* }*
* // 1400 -> 1102*
* // 1800 -> 1500*
* // 2000 -> 1703*
* // 2300 -> 2000*
* // 2500 -> 2000*
* delay(delay_of_loop);
_}_
ISR(TIMER1_COMPA_vect) { //leave this alone
_ cli(); //stop interrupts*_
* static boolean state = true;*
* TCNT1 = 0;*
* if (state) { //start pulse*
* digitalWrite(sigPin, onState);*
OCR1A = PPM_PulseLen * 2;
* state = false;*
* }*
* else { //end pulse and calculate when to start the next pulse*
* static byte cur_chan_numb;
static unsigned int calc_rest;
_ digitalWrite(sigPin, !onState);_
_ state = true;_
if (cur_chan_numb >= chanel_number) {
cur_chan_numb = 0;
calc_rest = calc_rest + PPM_PulseLen;//
OCR1A = (PPM_FrLen - calc_rest) * 2;
calc_rest = 0;
_ }_
_ else {_
OCR1A = (ppm[cur_chan_numb] - PPM_PulseLen) * 2;
calc_rest = calc_rest + ppm[cur_chan_numb];
cur_chan_numb++;
_ }_
_ }_
_ sei(); //allow interrupts*_
}
plz help us guys
