c - 尝试使用timer_A来控制LED

Question

我正在尝试创建一个代码，它接收来自 4x3 键盘的输入，然后将该输入转换为占空比，使用 Timer_A 来调整 LED 的强度。但是我的代码无法正常工作，我想知道代码需要进行哪些更改。该代码成功打印了 setLED 中的 J 值，但对 LED 没有任何影响。我还成功地测试了 Timer_A 本身，以确保电路接线正确。谢谢

#include "msp.h"
#include < stdio.h >

uint8_t Read_Keypad(); //Reads keypad
void InitKeypad(); //GPIO initialization of keypad
void InitTimer();
void printKey(); //Print the pressed key
void SaveInput(); //Stores the pressed number
void setDutyCylce(); //Converts an integer to a string character
void setLED();

uint32_t num;
uint8_t i = 0, k = 0;
float dCycle, period = 3000-1, j = 0.0, tempDC;
int a1[3];

int main(){
  WDT_A->CTL = WDT_A_CTL_PW | // Halts Watch dog
  WDT_A_CTL_HOLD;
  uint8_t pressed = 0;
  InitKeypad();
  InitTimer();
  printf("\nPlease enter a duty cycle.\n\n"); //Request keypad entry
  while(1){ //Loop used to run through the keypad sequencing indefinitely
    pressed = Read_Keypad(); // Calls Function that reads Keypad
    if(pressed){ // If a button is pressed this will be true
      printKey(); // Call print key to display the pressed key
      SaveInput(); // Call SaveInput Store the acsii value into a character array
      setDutyCylce(); // Used to convert an integer to a string character
      setLED();
      __delay_cycles(30000); // delay for 10ms each time through the loop before reading keypad //again
    }
  }
}
void InitKeypad(){
  //Sets the whole P4 register as GPIO
  P4SEL0 &=~0xFF; P4SEL1 &=~0XFF;
  // Set Keypad Row0 to P4.0 Row1 to P4.1 Row2 to P4.2 Row3 to P4.3
  P4->DIR &=~ (BIT0 | BIT1 | BIT2 | BIT3);
  // Enable pull-up resistor on all rows P4.0, P4.1, P4.2, P4.3
  P4REN |= (BIT0 | BIT1 | BIT2 | BIT3);
  // Configure rows with pull-up rows P4.0, P4.1, P4.2, P4.3
  P4OUT |= (BIT0 | BIT1 | BIT2 | BIT3);
  // Set Keypad Columns to Inputs P4.6 Col_1 P4.5 Keypad Col_0 P4.4
  P4->DIR &=~(BIT4 | BIT5 | BIT6);
}
void InitTimer(){
  P2->DIR |= BIT4; // P2.4 set TA0.1 P2->SEL0 |= BIT4;
  P2->SEL0 |= BIT4;
  P2->SEL1 &= ~(BIT4);
  TIMER_A0->CCR[0] = period; // PWM Period (# cycles of the clock)
  TIMER_A0->CCTL[1] = TIMER_A_CCTLN_OUTMOD_7;
  TIMER_A0->CCR[1] = dCycle; // CCR1 PWM duty cycle in 10ths of percent
  TIMER_A0->CTL = TIMER_A_CTL_SSEL__SMCLK | TIMER_A_CTL_MC__UP | TIMER_A_CTL_CLR;
}
uint8_t Read_Keypad(){
  uint8_t col,row;
  for(col=0; col<3; col++){
    P4->DIR = 0x00; // Set Columns to inputs
    P4->DIR |= BIT(4 + col); // Set Column 3 to Output
    P4->OUT &=~ BIT(4 + col); // Set Column 3 to LOW
    __delay_cycles(10); // Delay the while loop
    row = P4->IN & 0x0F; // Read all rows
    while(!(P4IN & BIT0)| !(P4IN & BIT1)| !(P4IN & BIT2) | !(P4IN & BIT3));
    if(row != 0x0F){ // If one of the inputs is low, some key is pressed.
      break; // Breaks out of the for loop
    }
  }
  P4->DIR |= 0x00; // Set Columns to inputs
  if (col == 3) return 0; // No button is was pressed during this iteration
  if (row == 0x0E) num = (col + 1); // Key in row 0
  if (row == 0x0D) num = (3 + col + 1); // Key in row 1
  if (row == 0x0B) num = (6 + col + 1); // Key in row 2
  if (row == 0x07) num = (9 + col + 1); // Key in row 3
  return 1;
}
void printKey(){
  if (num == 10) printf(" *\n"); // If the number is 10 the value is *
  if (num == 12) printf(" #\n"); // If the number is 12 the value is #
  if (num == 11){
    printf(" 0\n"); // If the number is 11 the value is 0
    num = 0;
  }
  if (num < 10) printf(" %d\n",num); // If any other number is pressed the value is the number
}
void SaveInput(){
  if(!(num == 10 || num == 12)){ // Prevent the characters * and # from being stored
    a1[0] = a1[1]; // Value at index 0 will be overwritten and go away
    a1[1] = a1[2]; // Shift all index values to the left
    a1[2] = num; // The newest value to be stored
    i++; // Used to ensure 4 number have been entered
  }
}
void setDutyCylce(){ //converts input to a percentage, then pwm cycle
  if(i >= 1 && num == 12){
    tempDC = a1[0];
    tempDC = (tempDC * 10) + a1[1] ;
    j = (tempDC * 10) + a1[2];
    tempDC = (j/100);
    dCycle = (tempDC * period);
    a1[0] = 0;
    a1[1] = 0;
    a1[2] = 0;
  }
}
void setLED(){
  if(i >= 1 && num == 12 && j <= 100){
    P2->OUT |= BIT4; //turns ON
    printf("LED now operating with %.1f power.\n", j);
    i=0;
  }
  if(i >= 1 && num == 12 && j > 100){
    printf("\n Invalid duty cycle.\n", j);
    P2->OUT &=~ BIT4; //turns OFF
    i=0;
  }
}

Answer 1

我确实需要更多有关硬件的信息。

乍一看，我会说您正在 setDutyCycle 中更改 dCycle，但仅在 InitTimer 中使用 dCycle > 只调用一次。

将 pwm 占空比初始化为声明一次的 dCycle 后，您的意思是通过 while 循环一次又一次地更改吗？