Compiler Error "... does not name a type"

Hello folks,

i tried to compile this code:

struct Packet {
    char header[7];
};

Packet p;


void setup()
{
  p = Packet();
}

void loop()
{
}

Packet recNextPacket(){  
  return p;
}

but the Compiler tells me at validation: "sketch_nov16a:0: error: 'Packet' does not name a type"

Pls help!

MFG

struct Packet {
    char header[7];
};

struct Packet p;

Or:

typedef struct  {
    char header[7];
}Packet;

Packet p;

thank you very much!

Problem solved.

MFG

ok I got another problem.

i hope this doesnt make too much effort for you:

this is the code:

#include "WProgram.h"
#define INT_16 int
#define UINT_16 unsigned int
#define INT long
#define UINT_32 unsigned long

UINT_32 timerInit(){
    return millis();
}

UINT_32 timerDiff(UINT_32 zeitstempel){
    if(millis()<zeitstempel)return (((UINT_32)-1)-zeitstempel)+millis();
    return millis()-zeitstempel;
}

INT_16 readData(char* buffer, INT_16 len)
{
    INT_16 bytesRead=0;
    while(Serial.available() > 0 && bytesRead < len)
        {
            *buffer = Serial.read();
            buffer++;
            bytesRead++;
        }
    return bytesRead;
}

bool sendData(const void * buffer, INT_16 nSize)
{
    Serial.write((const uint8_t*)buffer, nSize);
}

void closeSerialPort()
{
    Serial.end();
}

bool initializeSerialPort(const char* cpDevice)
{
    Serial.begin(9600); //Bei Änderungen auch Baudrate auf Server-Seite ändern!
    return true;
}


#define protName "LBUKAS"


void ntohs(uint16_t* value) {
  uint16_t tmp_a = (*value & 0xff00) >> 8;
  uint16_t tmp_b = (*value & 0x00ff) << 8;
  *value = tmp_b | tmp_a;
}

void ntohl(uint32_t* value) {
  uint32_t tmp_a = (*value & 0xff000000) >> 24;
  uint32_t tmp_b = (*value & 0x00ff0000) >> 8;
  uint32_t tmp_c = (*value & 0x0000ff00) << 8 ;
  uint32_t tmp_d = (*value & 0x000000ff) << 24;
  *value = tmp_d | tmp_c |tmp_b | tmp_a;
}

struct Packet{
    char header[7];
    INT_16 checksum;
    UINT_16 packetNUM;
    bool ack;
    UINT_32 data;
};


class Traffic{
private:
    UINT_16 packetNumber;

    void shiftLeftCharArray(char * p,int size){
        for(int i=0;i<size-1;i++){
            *p = *(p+1);
            p++;
        }
    }

public:
   struct Packet recNextPacket(UINT_32 timeout){
        int bytesRead=0;
        struct Packet p = Packet();
        char * head = (char*)p.header;
        UINT_32 timer = timerInit();
        do{
            do{
                int br = readData(head, sizeof(p.header)-bytesRead);
                head += br;
                bytesRead += br;
            }while(bytesRead<sizeof(p.header)&&(timerDiff(timer)<timeout)); //Header aus Datenstrom ausgelesen.
            if(timerDiff(timer)<timeout)break;
            if(strcmp(protName,p.header))break; // der Paketanfang wurde gefunden
            //ansonsten...
            shiftLeftCharArray((char*)p.header,sizeof(p.header));
            bytesRead=sizeof(p.header)-1;
            head = (char*)p.header+sizeof(p.header)-1;
        }while(timerDiff(timer)<timeout);
        head=(char*)&p;
        head+=sizeof(p.header);
        while(timerDiff(timer)<timeout);{
            int br = readData(head, sizeof(p)-bytesRead-sizeof(p.header));
            head += br;
            bytesRead += br;
        }
        if(timerDiff(timer)<timeout)p.packetNUM=0; // wir setzen packetNUM auf null, falls das Paket nicht gänzlich empfangen wurde!
        return p;
    }

    ~Traffic(){
        closeSerialPort();
    }

    Traffic(){
      initializeSerialPort("\0");
      packetNumber=1;
      //warteschlange = PacketSpeicher();
    }

    bool sendTicks(UINT_16 ticks, UINT_32 timeout){
        struct Packet p = Packet();
        strcpy(p.header, protName);
        p.packetNUM=packetNumber;
        p.checksum=0;
        p.data=ticks;
        p.ack=false;
        UINT_32 timer = timerInit();
        sendData(&p,sizeof(struct Packet));
        do{
            if(packetNumber==recieveACK(timeout-timerDiff(timer))){
                packetNumber++;
                return true;
            }
        }while(timerDiff(timer)<timeout);
        return false;
    }

    INT_16 recieveACK(UINT_32 timeout){
        struct Packet p;
        UINT_32 timer = timerInit();
        do{
            p = recNextPacket(timeout-timerDiff(timer));
        }while(p.ack==false && timerDiff(timer)<timeout);
        if(timerDiff(timer)<timeout)return NULL;
        return p.packetNUM;
    }

    INT_16 recieveTicks(){
        struct Packet p = recNextPacket(1);
        return p.data;
    }
};


Traffic traffic;

void setup()
{
  traffic = Traffic();
}

void loop()
{
  delay(1000);
  Serial.write("test");
}

this code compiles and uploads its binary to the arduino. But if i listen to the serial, nothing gets send!

Pls help again!

It has to be a problem with the initialization of the Traffic class.
If i take the same code, but exchanging the setup function with this:

void setup()
{
  Serial.begin(9600);
  //traffic = Traffic();
}

the program works fine!

Best regards!

Traffic traffic;

This has created an instance of the Traffic class, and stored that in a variable called traffic.

traffic = Traffic();

stomps on the definition of traffic assigning it what was returned by the constructor, which is not what you think it is.

In C++, you would new the new operator to assign what the constructor returned to a pointer. The new operator is not implemented for the Arduino, so you can't use the normal create an instance of a class process. Calling the constructor directly is not a good thing.

ah, allright. Thank you very much. Good answer!

I came from Java programming to C++ and I am still a C newbie. I made the mistake because of the missing "new" Operator. Im sry for annoying you with such trivial questions. But now my program works thanks to you and the Community ^^.

Problem solved!

JanUlrich: I made the mistake because of the missing "new" Operator.

FWIW, the forthcoming 1.0 release of the Arduino IDE provides the 'new' and 'delete' operators, at least they are in rc2.

#define Kpw 3200 //коэффициент пересчета импульсов счетчика
#define KPtim 3600000000/Kpw //коэфф.для подсчета мощности по
//длит.периода импульсов (длительности мерим в мс)
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x3f,16,2);

unsigned long time;
unsigned long timeM;
unsigned long timeOld;
unsigned long PerImp;
const int pinPw = 8; //вывод для подключения оптрона счетчика эл.эн.
byte pinPwOld = 1; //старое значение состояния входа
long datD;
byte i;

//Установка Таймера2.
//Конфигурирует 8-битный Таймер2 ATMega168 для выработки прерывания
//с периодом около 16 мс.
void SetupTimer2() {
//Установки Таймер2: Делитель частоты /1024, режим 0
//Частота = 16MHz/1024 = 16.384 мс
TCCR2A = 0;
TCCR2B = 1<<CS22 | 1<<CS21 | 1<<CS20; //на 1024
//Подключение прерывания по переполнению Timer2
TIMSK2 = 1<<TOIE2;
}

//Timer2 указатель вектора прерывания по переполнению
ISR(TIMER2_OVF_vect) {
//приращение переменной
time ++;
int valpinPw = digitalRead(pinPw);
if (valpinPw == 0) {pinPwOld = 0;}
else {
if (pinPwOld == 0)
{ pinPwOld = 1;
timeM = millis();
PerImp = timeM - timeOld;
timeOld = timeM;
}
}
}

void setup() {
//для подсчета мощности
time = 0;
timeOld = millis();
PerImp = 1;
pinMode(pinPw, INPUT);
digitalWrite(pinPw, 1); // вкл внутр резистор
Serial.begin(9600);
SetupTimer2(); //прерывания таймера - подчет мощности
}

void loop() {
datD = KPtim/PerImp; //текущая потребляемая мощность
Serial.print("Power = ");
Serial.println(datD);
delay(10000);
}
lcd.init() // initialize the lcd
lcd.print("Power = ");
lcd.println(datD); ------------------‘lcd’ does not name a type ???
delay(10000);
}

This is ALL of loop():

void loop() {
 datD = KPtim/PerImp;  //текущая потребляемая мощность
 Serial.print("Power = ");
 Serial.println(datD);
 delay(10000);
}

This code:

 lcd.init()             // initialize the lcd
 lcd.print("Power = ");
 lcd.println(datD);      ------------------'lcd' does not name a type ??????
 delay(10000);
}

is NOT in a function. ALL code MUST be in a function.