if equals不匹配,但应该匹配。Aduino IDE串行

我正试图让一个树莓派通过串行与arduino通信,硬件已经全部设置好,还有一些通信可以。

我遇到的问题是,传递的参数与if,else-if表达式不匹配,但实际上应该偏离返回的内容。

SerialCommand library 处理哪些命令触发哪些功能。对于这个例子,我们只对sayHello()感兴趣。RaspberryPi发送“HELLO HELLO”,它应该会收到“YES HELLO”但我总是收到“NO HELLO”提示在arg HELLO上没有匹配。很明显,不管怎样,收到的论点都会得到回应,我收到的应该是匹配的,你好,所以我在这个阶段被难住了,有什么建议吗?

编辑:感谢Thanushan Balakrishnan在下面的回答中的评论,替换

if(arg == "HELLO")

通过以下操作修复了问题。

if(strcmp("HELLO", arg) == 0)

_

// Demo Code for SerialCommand Library
// Steven Cogswell
// May 2011


// temp & Humidity
#include <DHT22.h>
#define DHT22_PIN 12
// Setup a DHT22 instance
DHT22 myDHT22(DHT22_PIN);

// tank water level
int sensorValue = 0;
int constrainedValue = 0;
int tankLevel = 0;
#define TANK_SENSOR 0
#define TANK_EMPTY 0
#define TANK_FULL 1023


/*RelayBrd */
//Pin connected to latch pin (ST_CP) of 74HC595
const int latchPin = 4;
//Pin connected to clock pin (SH_CP) of 74HC595
const int clockPin = 3;
////Pin connected to Data in (DS) of 74HC595
const int dataPin = 2;
boolean thisState = LOW;


#include <SerialCommand.h>
#define arduinoLED 13   // Arduino LED on board

SerialCommand sCmd;     // The demo SerialCommand object

void setup() {
  pinMode(arduinoLED, OUTPUT);      // Configure the onboard LED for output
  digitalWrite(arduinoLED, LOW);    // default to LED off

  //mySerial.begin(9600);
  //mySerial.println("Ready");

  Serial.begin(115200);

  // Setup callbacks for SerialCommand commands
  sCmd.addCommand("ON",   LED_on);          // Turns LED on
  sCmd.addCommand("OFF",  LED_off);         // Turns LED off

  sCmd.addCommand("getenv",   getEnv);
  sCmd.addCommand("relaybrd",   relayBrd);
  sCmd.addCommand("gettanklevel",   getTankLevel);
  sCmd.addCommand("setlouver",   setLouver);
  sCmd.addCommand("HELLO", sayHello);        // Echos the string argument back
  sCmd.addCommand("P",     processCommand);  // Converts two arguments to integers and echos them back
  sCmd.setDefaultHandler(unrecognized);      // Handler for command that isn't matched  (says "What?")
  Serial.println("Ready");
}

void loop() {
  sCmd.readSerial();     // We don't do much, just process serial commands

 // if (mySerial.available())
 //   Serial.write(mySerial.read());
 // if (Serial.available())
 //   mySerial.write(Serial.read());

}



void relayBrd(){

  char *arg;
  char *arg1;
  arg = sCmd.next();
  arg1 = sCmd.next();


  if (arg != NULL) {
    //int num = atol(arg);
    if (arg1 != NULL) {
       int state = atol(arg1);
       if (arg == "fan") {
          //do something when var equals 1
          registerWrite(1, state);

       }else if(arg == "water"){
          //do something when var equals 2
          registerWrite(2, state);

      }else if(arg == "mister"){
          //do something when var equals 2
          registerWrite(3, state);

      }else if(arg == "heater"){
          //do something when var equals 2
          registerWrite(4, state);

      }else{ 
          // if nothing else matches, do the default
          Serial.print("ERR got:");Serial.print(arg);Serial.println(":");
      }
    }else{
        Serial.println("ERR Relay state missing 1/0");
    }  

  }else{
    Serial.println("ERR Relay argument missing fan/water/heater/mister");
  }




}

// This method sends bits to the shift register:

void registerWrite(int whichPin, int whichState) {

     Serial.print("Relay ");Serial.print(whichPin);Serial.print(" set to ");Serial.println(whichState);
// the bits you want to send
  byte bitsToSend = 0;

  // turn off the output so the pins don't light up
  // while you're shifting bits:
  digitalWrite(latchPin, LOW);

  // turn on the next highest bit in bitsToSend:
  bitWrite(bitsToSend, whichPin, whichState);

  // shift the bits out:
  shiftOut(dataPin, clockPin, MSBFIRST, bitsToSend);

    // turn on the output so the LEDs can light up:
  digitalWrite(latchPin, HIGH);

}

void getEnv(){
  Serial.println("26 degC");
   DHT22_ERROR_t errorCode;
 Serial.print("Requesting data...");
  errorCode = myDHT22.readData();
  switch(errorCode)
  {
    case DHT_ERROR_NONE:
      Serial.print("Got Data ");
      Serial.print(myDHT22.getTemperatureC());
      Serial.print("C ");
      Serial.print(myDHT22.getHumidity());
      Serial.println("%");
      break;
    default:
    Serial.print("ERR DHT22 ");
    Serial.println(errorCode);
  }

}




void getTankLevel(){
  Serial.println("78% water level");
  sensorValue = analogRead( TANK_SENSOR );
  constrainedValue = constrain( sensorValue, TANK_EMPTY, TANK_FULL );
  tankLevel = map( constrainedValue, TANK_EMPTY, TANK_FULL, 0, 100 );

}

void setLouver() {
  char *arg;


  arg = sCmd.next();
  if (arg != NULL) {
    if(arg == "OPEN"){
         Serial.println("Louver OPEN");
    }else if(arg == "CLOSE"){
          Serial.println("Louver CLOSED");
    }else{
    Serial.print(arg);Serial.println(" not known");
    }
  }else{
    Serial.println("Louver command missing OPEN/CLOSE");
  }
}  

void LED_on() {
  Serial.println("LED on");
  digitalWrite(arduinoLED, HIGH);
}

void LED_off() {
  Serial.println("LED off");
  digitalWrite(arduinoLED, LOW);
}

void sayHello() {
  char *arg;
  arg = sCmd.next();    // Get the next argument from the SerialCommand object buffer

  if (arg != NULL) {    // As long as it existed, take it
    if (arg == "HELLO") {    // As long as it existed, take it
    Serial.print("YES ");
    Serial.println(arg);
    }else{
       Serial.print("NO ");
    Serial.println(arg);
    }
  }
  else {
    Serial.println("Hello Pi");
  }
}


void processCommand() {
  int aNumber;
  char *arg;

  Serial.println("We're in processCommand");
  arg = sCmd.next();
  if (arg != NULL) {
    aNumber = atoi(arg);    // Converts a char string to an integer
    Serial.print("First argument was: ");
    Serial.println(aNumber);
  }
  else {
    Serial.println("No arguments");
  }

  arg = sCmd.next();
  if (arg != NULL) {
    aNumber = atol(arg);
    Serial.print("Second argument was: ");
    Serial.println(aNumber);
  }
  else {
    Serial.println("No second argument");
  }
}

// This gets set as the default handler, and gets called when no other command matches.
void unrecognized(const char *command) {
  Serial.println("What?");
}