从TI官网下的launchpad触摸板例程求问。。

从TI官网下的launchpad触摸板例程 编译时无错误，MAKE时出现如下错误，用的是IAR软件，不知道那个库没设置好，还是路径问题，求解答。
Error[e46]:
Undefined external "wheel_buttons" referred in main (
E:\430itouch\Getting_Started_Projects\IAR\Debug\Obj\main.r43 )
Error[e46]:
Undefined external "up_element" referred in main (
E:\430itouch\Getting_Started_Projects\IAR\Debug\Obj\main.r43 )
Error[e46]:
Undefined external "down_element" referred in main (
E:\430itouch\Getting_Started_Projects\IAR\Debug\Obj\main.r43 )
Error[e46]:
Undefined external "left_element" referred in main (
E:\430itouch\Getting_Started_Projects\IAR\Debug\Obj\main.r43 )
Error[e46]:
Undefined external "right_element" referred in main (
E:\430itouch\Getting_Started_Projects\IAR\Debug\Obj\main.r43 )
Error while
running Linker

这是代码；

//******************************************************************************
// RO_PINOSC_TA0_WDTp_Wheel_Buttons example
// Touch the five wheel buttons to turn on/off the center button LED
// RO method capactiance measurement using PinOsc IO, TimerA0, and WDT+
//
//          Schematic Description:
//
//                         MSP430G2452
//                      +---------------+
//                      |
//             C--------|P2.4
//           C----------|P2.1
//               C------|P2.3
//             C--------|P2.2
//                      |
//           C----------|P2.5
//                      |
//           C----------|P2.0
//
//        The WDT+ interval represents the measurement window.  The number of
//        counts within the TA0R that have accumulated during the measurement
//        window represents the capacitance of the element. This is lowest
//        power option with either LPM3 (ACLK WDTp source) or LPM0 (SMCLK WDTp
//        source).
//
//******************************************************************************
#include "CTS_Layer.h"

// Uncomment to have this compiler directive run characterization functions only
// Comment to have this compiler directive run example application
//#define ELEMENT_CHARACTERIZATION_MODE 

#define DELAY 5000   // Timer delay timeout count, 5000*0.1msec = 500 msec

struct Element * keyPressed;   // Pointer to the Element structure

#ifdef ELEMENT_CHARACTERIZATION_MODE
// Delta Counts returned from the API function for the sensor during characterization
unsigned int wheelCnt[5];    // Becuase the Wheel is composed of five elements
#endif

// Sleep Function
// Configures Timer A to run off ACLK, count in UP mode, places the CPU in LPM3
// and enables the interrupt vector to jump to ISR upon timeout
void sleep(unsigned int time)
{
    TA0CCR0 = time;
    TA0CTL = TASSEL_1+MC_1+TACLR;
    TA0CCTL0 &= ~CCIFG;
    TA0CCTL0 |= CCIE;
    __bis_SR_register(LPM3_bits+GIE);
    __no_operation();
}

// Main Function
void main(void)
{
  WDTCTL = WDTPW + WDTHOLD;             // Stop watchdog timer
  BCSCTL1 = CALBC1_1MHZ;                // Set DCO to 1, 8, 12 or 16MHz
  DCOCTL = CALDCO_1MHZ;
  BCSCTL1 |= DIVA_0;                    // ACLK/1 [ACLK/(0:1,1:2,2:4,3:8)]
  BCSCTL2 |= DIVS_3;                    // SMCLK/8 [SMCLK/(0:1,1:2,2:4,3:8)]
  BCSCTL3 |= LFXT1S_2;                  // LFXT1 = VLO Clock Source
 
  P1OUT = 0x00;       // Drive all Port 1 pins low
  P1DIR = 0xFF;       // Configure all Port 1 pins outputs
 
  P2SEL &= ~(BIT6 + BIT7);    // Configure XIN (P2.6) and XOUT (P2.7) to GPIO
  P2OUT = 0x00;       // Drive all Port 2 pins low
  P2DIR = 0xFF;       // Configure all Port 2 pins outputs

  // Initialize Baseline measurement
  TI_CAPT_Init_Baseline(&wheel_buttons);
 
  // Update baseline measurement (Average 5 measurements)
  TI_CAPT_Update_Baseline(&wheel_buttons,5); 

  // Main loop starts here
  while (1)
  {
   
   #ifdef ELEMENT_CHARACTERIZATION_MODE
 // Get the raw delta counts for element characterization
 TI_CAPT_Custom(&wheel_buttons,wheelCnt);
 __no_operation();      // Set breakpoint here 
 #endif
 
 
 #ifndef ELEMENT_CHARACTERIZATION_MODE
 // Return the pointer to the element which has been touched
 keyPressed = (struct Element *)TI_CAPT_Buttons(&wheel_buttons);
 
 // If a button has been touched, then take some action
 if(keyPressed)
 {
  // Up Element
  if(keyPressed == &up_element)
  {
   P1OUT |= BIT0;    // Turn on center LED
  }
  // Down Element
  if(keyPressed == &down_element)
  {
   P1OUT |= BIT0;    // Turn on center LED
  }
  // Left Element
  if(keyPressed == &left_element)
  {
   P1OUT |= BIT0;    // Turn on center LED
  }
  // Right Element
  if(keyPressed == &right_element)
  {
   P1OUT |= BIT0;    // Turn on center LED
  }      
  // Middle Element
  if(keyPressed == &middle_element)
  {
   P1OUT |= BIT0;    // Turn on center LED
  }
   }
   else
   {
       P1OUT &= ~(BIT0);    // Turn off center LED
   }     
       
    // Put the MSP430 into LPM3 for a certain DELAY period
    sleep(DELAY);
    #endif

  }
} // End Main

/******************************************************************************/
// Timer0_A0 Interrupt Service Routine: Disables the timer and exists LPM3 
/******************************************************************************/
#pragma vector=TIMER0_A0_VECTOR
__interrupt void ISR_Timer0_A0(void)
{
  TA0CTL &= ~(MC_1);
  TA0CCTL0 &= ~(CCIE);
  __bic_SR_register_on_exit(LPM3_bits+GIE);
}