將代碼從ATmega32修改爲Arduino兆 - 函數`main'中的錯誤（即使沒有）

Question

我試圖修改此代碼，試圖使其工作在Arduino Mega上。我對C非常陌生，所以我可能犯了一些重大錯誤。順便說一下，這是一個自平衡滑板。

此代碼取自ATmega32（從here，我試圖使它在Arduino Mega上工作）。

此代碼是爲ATmega32 development board寫的。

但我會遇到這樣的錯誤：

o: In function main':</br> C:\Users\*******\AppData\Local\Temp\build27006.tmp/Test2.cpp:406:</br> undefined reference to setup'

怎麼來的？我甚至沒有在這裏參考setup！

這裏是我的代碼：

#include <avr/io.h> 
#include <avr/pgmspace.h> 
#include <avr/interrupt.h> 
#include <math.h> 

#define CLOCK_SPEED 16000000 
#define OCR1_MAX 1023 

typedef unsigned char u8; 
void set_motor_idle(void); 
void InitPorts(void); 
float level = 0; 
float Throttle_pedal; 
float aa; 
float accelraw; 
float x_acc; 
float accsum; 
float x_accdeg; 

float gyrosum; 

float gangleratedeg; 
float gangleraterads; 
float ti = 2.2; 

float overallgain; 
float gaincontrol; 
float batteryvolts = 24; 
float gyroangledt; 
float angle; 
float anglerads; 
float balance_torque; 
float softstart; 

float cur_speed; 
float cycle_time = 0.0064; 
float Balance_point; 
float a0, a1, a2, a3, a4, a5, a6; //Savitzky-Golay variables for accelerometer. 

float TCCR0; 

int i; 
int j; 
int tipstart; 

void InitPorts(void) 
{ 
    PORTC = 0x00; //Port C pullups set to low (no output voltage) to begin with. 
    DDRC = 0xFF; //Port C pins all set as output via the port C direction register. 
    //PORTC |= (1<<PC1); //Make C1 +ve so disables OSMC during startup. 

    DDRA = 0x00; //All port A pins set as input. 
    PORTA = 0x00; //Port A input pullups set to low pullups. 

    DDRD = 0xFF; //Configure all port D pins as output as prerequisite 
       //for OCR1A (PinD5) and OCR1B (Pin D4) working properly. 

    PORTB = 0x00; //Port B pullups set to low (no output voltage) to begin with. 
    DDRB = 0xFF; //All port B pins set to output. 
} 

/* 
    IO: 

    I am using a ATMega32 16 MHz with an external crystal clock. New planned pin 
    arrangement to OSMC motor controller. 

    PC4  Onboard LED 
    PD5/OC1A ALI -> OSMC pin 6 
    PD4/OC1B BLI -> OSMC pin 8 
    PC1  Disable -> OSMC pin 4 
    PC2  BHI -> OSMC pin 7 
    PC3  AHI -> OSMC pin 5 
    PA6/ADC6 Vbatt/10 -> OSMC pin 3 
    PA1/ADC1 pitch rate gyro 
    PA0/ADC0 accelerometer 
*/ 

void adc_init(void) { 
    /* Turn off analogue comparator as we don't use it */ 
    ACSR = (1 << ACD); 

    /* Select PA0 */ 
    ADMUX = 0; 
    ADMUX |=(1<<REFS0); //This tells it to use VCC (approx. 5 V) as the reference 
         //voltage NOT the default which is the internal 2.5V reference 
    /* Set ADC prescaler to 128, enable ADC, and start conversion. */ 
    ADCSRA = 0 | (1<<ADPS2) | (1<<ADPS1) | (1<<ADPS0) 
       | (1<<ADEN) //Enable ADC 
       | (1<<ADSC); //Start first conversion 
    /* Wait until bogus first conversion is finished */ 
    while (ADCSRA & (1 << ADSC)) { 
    } 
} 


uint16_t adc_read(uint8_t channel) { 
    /* Select channel */ 
    ADMUX = channel; 
    ADMUX |= (1<<REFS0); //Here it is again 
    /* Start conversion */ 
    ADCSRA |= (1 << ADSC); 
    /* Wait until conversion finished */ 
    while (ADCSRA & (1 << ADSC)) { 
    } 
    /* Return the result */ 
    return ADCW; 
} 

/* 156 cycles per sec, 6.4 ms per cycle MEASURED ON OSCILLOSCOPE. */ 
/* Read all the ADC inputs and do some conversion. */ 
void sample_inputs(void) { 
    uint16_t adc0, adc1, adc2, adc3, adc4, adc5; 

    gyrosum = 0; 
    adc0 = adc_read(0); /* Accelerometer pin PA0 */ 
    accelraw = (float) adc0; 

    for (j=0; j<7; j++) { 
     adc1 = adc_read(1); //Gyro pin PA1 
     gyrosum = (float) gyrosum + adc1; //Using a mean of 7 samples per loop for the gyro so 
              //it gets a complete update with each loop of the program. 
    } 

    adc2 = adc_read(2); /* Grey wire overallgain (via cutout switch), position PA2. */ 
    adc3 = adc_read(3); /* Position lever pulled back position PA3. */ 
    adc4 = adc_read(4); /* Throttle_pedal, position PA4. */ 
    adc5 = adc_read(5); /* Position lever pushed forwards, position PA5. */ 
    //adc6 = adc_read(6); /* Vbatt input from OSMC (not used at present), position PA6. */ 

    //Sav Golay filter for accelerometer only. 
    a0 = a1; 
    a1 = a2; 
    a2 = a3; 
    a3 = a4; 
    a4 = a5; 
    a5 = a6; 
    a6 = (float) accelraw; 
    accsum = (float) ((-2*a0) + (3*a1) + (6*a2) + (7*a3) + 
         (6*a4) + (3*a5) + (-2*a6))/21; //Sav Golay calculation 

    gaincontrol = (float) gaincontrol*0.9 + 0.1*adc2/341; //Smooths any voltage spikes and gives range 0-3. 

    Throttle_pedal=(float) Throttle_pedal*0.9 + 0.1*adc4/341; //Smooths any voltage spikes and gives range 0-3 

    //Cuts the motor if the dead mans button is let go 
    //(gaincontrol variable also wired in through this button to adc2 
    if (adc2<100) { 
     Throttle_pedal = 0.001; 
     gaincontrol = 0.001; 
    } 

    overallgain = gaincontrol*softstart; 

    //What to do if the lever is pulled back or pushed forwards or not doing anything: 
    Balance_point = 514; 

    if (adc3 > 100) 
     Balance_point = 534; 

    if (adc5>100) 
     Balance_point = 494; 

    PORTB |= (1<<PB2); //Port B2 turned on/off once per loop so I can measure 
         //loop time with an oscilloscope 

    /*ACCELEROMETER signal processing*/ 

    /*Subtract offsets*/ 

    x_acc = (float) accsum - Balance_point; //accsum is SG value for accelerometer, not 
              //a true "sum" so no need to divide by 7 

    if (x_acc < -250) 
     x_acc = -250; //Cap acceleration values to a range of -250 to +250 (80 
         //degree tilt each way). 
    if (x_acc > 250) 
     x_acc = 250; 

    /* Accelerometer angle change is about 3.45 units per degree tilt in 
     range 0-30 degrees(sin theta). Convert tilt to degrees of tilt from 
     accelerometer sensor. Sin angle roughly = angle for small angles so 
     no need to do trigonometry. x_acc below is now in DEGREES */ 

    x_accdeg= (float) x_acc/-3.45; //The minus sign corrects for a back 
            //to front accelerometer mounting! 

    /* GYRO signal processing*/ 

    /* Subtract offsets: Sensor reading is 0-1024 so "balance point" i.e. my required 
     zero point will be that reading minus 512. */ 

    /* Gyro angle change of 20mV per deg per sec from datasheet gives change 
     of 4.096 units (on the scale of 0 - 1023) per degree per sec angle change. 
     This limits the rate of change of gyro angle to just less than the 
     maximum rate it is actually capable of measuring (100 deg/sec). Note 
     all these fractions are rounded up to an integer later just before 
     it is sent to the PWM generator which in turn is connected to the 
     motor controller. */ 

    gangleratedeg = (float)((gyrosum/7) - 508)/4.096; //gyrosum is a sum of a group 
                 //of 7 samples so divide by 7 for gyro value 
    if (gangleratedeg < -92) 
     gangleratedeg = -92; 
    if (gangleratedeg > 92) 
     gangleratedeg = 92; 

    /* I turn port B2 on and off once per main program cycle so I can attach an 
     oscilloscope to it and work out the program cycle time. 
     I use the cycle time to work out gyro angle change per cycle where you 
     have to know the length of this time interval. */ 
    PORTB &= (0<<PB2); 

    /* ti represents scaling for the "i" or integral factor (currently 2.2 here) 
     gyroangledt is anglechange since last CYCLE in degrees from gyro sensor, 
     where ti is scaling factor (should in theory be about 1 but 2.2 makes 
     board feel tighter) 

     ganglerate is now in units of degrees per second. 
     aa varies the time constant, that is, a smaller aa value makes 
     accelerometer time constant longer as it slowly corrects for 
     the gyro drift. */ 

    aa=0.005; 

    gyroangledt = (float)ti*cycle_time*gangleratedeg; 
    gangleraterads = (float)gangleratedeg*0.017453; 

    /* New angle in DEGREES is old angle plus change in angle from gyro 
     since last cycle with little bit of new accel reading factored in. */ 
    angle = (float)((1-aa) * (angle+gyroangledt)) + (aa * x_accdeg); //The main angle calculating function*/ 

    //Convert angle from degrees to radians 

    anglerads=(float)angle*0.017453; 

    balance_torque=(float)(4.5*anglerads) + (0.5*gangleraterads); 

    cur_speed = (float)(cur_speed + (Throttle_pedal * balance_torque * cycle_time)) * 0.999; 

    /* The level value is from -1 to +1 and represents the duty cycle to be sent to 
     the motor. Converting to radians helps us stay within these limits. */ 

    level = (balance_torque + cur_speed) * overallgain; 
} 

/* Configure timer and set up the output pins OC1A(Pin PD5 on my micro) and 
    OC1B (Pin PD4 on my micro) as phase-correct PWM channels. 

    Note: Some strongly feel that locked-antiphase is the way to go as get 
    regenerative braking and good control around mid-balance point. The downside 
    is that you can get a lot more noise and voltage spikes in system but 
    these can be smoothed out with filters. 

    Others are far more expert on this than I am so need to look into this 
    for yourself but this is my understanding. 

    My aim is to start with phase-correct as I just about understand it and 
    others have used it OK, then develop from there. */ 
void timer_init() 
{ 
    TCCR0 = 0 | 
    (1<<CS02) | (1<<CS01) | (1<<CS00); // External clock to Pin T0 Clock on rising edge/1024 

    // PWM mode is "PWM, Phase Correct, 10-bit" 
    TCCR1A = 0 | 
     (1<<COM1A1) | (1<<COM1A0) | // set on match up, clear on match down 
     (1<<COM1B1) | (1<<COM1B0) | // set on match up, clear on match down 

     (1<<WGM11) | (1<<WGM10); //OCR1_Max is 1023 so these are set like this 

    TCCR1B = 0 | 
     (1<<CS10); // Prescaler divide by 1 see P131 datasheet about prescaling 
         values to change here. 
    /* 16 MHz/1/1024/2 gives 8 kHz, probably about right. */ 
} 

void set_motor() 
/* The leveli terms is the level term rescaled from -1023 to +1023 as an 
    integer ready to send to the PWM motor control ports that are in 
    turn connected to the OSMC. */ 
{ 
    //if (level<-0.9) level= -0.9; //Checks we are within sensible limits 
    //if (level>0.9) level=0.9; 

    int16_t leveli = (int16_t)(level*1023); //NOTE: here we take the floating 
              //point value we have ended up with 
              //for "level", we multiply it by 1023 
              //and then make it into an integer 
              //before feeding the value into 
              //the PWM generator as "leveli" 

    if (leveli<-1020) 
     leveli=-1020; //Double-checks that we are within sensible PWM limits as do 
         //not want to suddenly be thrown off the board 
    if (leveli>1020) 
     leveli=1020; 

    /* Set up LED or buzzer on Port B1 to warn me to slow down if torque to be 
     delivered is more than 50% of max possible. The reason for this is that 
     you always need some reserve motor power in case you start tipping 
     forward at speed. If the motor is already running flat-out you would 
     be about to fall over at high speed! Some use an auto-tip back routine 
     to automatically limit top speed. For now I will do it this way as easier. */ 

    if (level<-0.7 || level>0.7) { 
     PORTB |= (1<<PB1); 
    } 
    else { 
     PORTB &= (0<<PB1); 
    } 

    softstart = (float) softstart+0.001; 
    if (softstart>1.0) 
     softstart=1.0; 

    //PORTC |= (0<<PC1); // AHI=1 PinC3, BHI=1 PinC2 set both to ON for OSMC to 
          //work and both to OFF to shut motor down. 

    /*NOTE: I am not sure why, but to stop the motor cutting out on direction 
      changes I had in the end to hard wire AHI and BHI to +12 V. */ 

    /* Un-disabled OSMC by setting PinC1 output to zero, a 1 would disable the OSMC. */ 
    PORTC |= 0x0c; //Make C1 pulled down so un-disables the OSMC i.e. enables it. 
    PORTC &= ~0x02; //Disable is off 
    if (leveli<0) { 
     OCR1A = -leveli; // ALI is PWM. Going backwards as leveli variable is a 
         //negative signed value, keep the minus sign in here! 
     OCR1B = 0;  // BLI = 0 
    } 
    else { 
     OCR1A = 0;  // ALI = 0  going forwards as leveli variable is a positive signed value 
     OCR1B = leveli; // BLI is PWM 
    } 
} 

void loop() 
{ 
    InitPorts(); 
    adc_init(); 
    timer_init(); 

    /* Initial tilt-start code 
     Turn on micro while board tipped to one side, rider about to step 
     onto it, if tilt angle crosses zero (mid) point balance algorithm 
     becomes operational otherwise locked in this loop forever until 
     it is tipped to level position as rider gets onto the board. */ 
    tipstart=0; 
    accelraw = 0; 

    while (tipstart<1){ 
     // You need this to allow the SG filter to wind up to the proper 
     //stable value when you first turn machine on, before looking 
     //at the value of accsum (below). 

     for (i=0; i<20; i++) { 
      sample_inputs(); 
     } 

     if (accsum<504 || accsum>524) { 
      // if (x_accdeg>0) { 
      tipstart=0; 
     } 
     else { 
      tipstart=1; 
      softstart=0.4; 
     } 
    } 

    angle=0; 
    cur_speed=0; 
    /* End of tilt start code. If go beyond this point then machine 
     has become level and is active. */ 

    sei(); 

    while (1) { 
     sample_inputs(); 
     set_motor(); 
    } 
} 

順便說一句，我使用的是Arduino的編譯器（你可以在Download the Arduino Software找到它）。

Answer 1

包含的代碼甚至沒有主要功能。它看起來像我的工具鏈中的安裝問題，否則你一直在調查錯誤的CPP文件。

查找測試2.cpp和線路406（在一個叫main功能）

Answer 2

How come? I dont even have a reference to setup in here!

那是因爲你沒有給setup一個參考，它的抱怨。

Arduino的代碼生成main是（在這裏討論）基本上是這樣的：

int main(int argc, char **argv) { 
    setup(); 
    while(1) { 
     loop(); 
    } 
} 

所以，你應該將loop功能重命名爲setup並藉此部分：

while (1) { 
    sample_inputs(); 
    set_motor(); 
} 

放下while循環，並將這兩個函數調用放入一個名爲loop的新函數中。

Answer 3

Arduino語言要求您定義兩個函數setup（）和loop（）。

如果你沒有什麼設置（），你應該定義一個空的功能，以滿足語言要求：

void setup() 
{ 
    // do nothing 
}