[参考译文] MSP430F5638：ADC12寄存器单个内部温度读取问题

/***************************************************************************************************************
 *
 * run_430_ADC_T() for internal Temperature
 * derived from TI MSP430F55xx_adc_10.c example, reads one channel one time
 *
 **************************************************************************************************************/
// setup and run in single temperature sensor mode
// runs continuously for now, ultimately only need 1 value, not averaging 10 values
void run_430_ADC_T(void)
{
    // local strings to hold LCD data
    unsigned char string1[LCD_ROW_WIDTH];

    // add breakpoint to stop here on debug
    __no_operation();

    WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT

    /***************************************************************************************************************
    * setup ADC12 for Temperature
    **************************************************************************************************************/

    REFCTL0 &= ~REFMSTR;                      // REF shared reference control register
                                              // Reset REFMSTR to hand over control to ADC12_A reference control registers, REF not used
    //ADC12CTL0 &= ~ADC12ON;                     // turn ADC off initially to clear ADC

    //     1111 11
    // msb 5432 1098 7654 3210 lsb
    //     0000 0000 0001 0000 = 0x0010     ADC12ON turn ADC12 on
    //     0000 0000 0010 0000 = 0x0020     ADC12REFON set reference on
    //     0000 1000 0000 0000 = 0x0800     ADC12SHT0_8 Sample Hold 0 Select Bit: 8,  (8*0x100u)
    //     ----------------------------
    //     0000 1000 0011 0000 = 0x0830     Total = ADC12CTL0 bit setting
    ADC12CTL0 = ADC12SHT0_8 + ADC12REFON + ADC12ON;     // Internal ref = 1.5V, Ref on, ADC on

    ADC12CTL1 = ADC12SHP;                     // enable sample timer, pulse mode, 0x0200

    //     1111 11
    // msb 5432 1098 7654 3210 lsb
    //     0000 0000 0000 1020 = 0x000A     ADC12INCH_10 ch A10 temperature sensor
    //     0000 0000 0001 0000 = 0x0010     ADC12SREF_1 select reference 1 (1*0x10u) = 0x10, VREF+, AVSS
    ADC12MCTL0 = ADC12SREF_1 + ADC12INCH_10;  // ADC i/p ch A10 = temp sense i/p

    ADC12IE = 0x001;                          // ADC_IFG upon conv result-ADCMEMO
    // it runs with or without the loop, but don't know accuracy without precise testing - leave the loop in for now
    __delay_cycles(100);                       // delay to allow Ref to settle
    // comment out while single stepping, it bogs down here
    ADC12CTL0 |= ADC12ENC;                     // enable conversion 0x0002

    /***************************************************************************************************************
    * read ADC12 Temperature
    **************************************************************************************************************/

    while(1)
    {
        ADC12CTL0 &= ~ADC12SC;                  // ensure sampling is stopped
        ADC12CTL0 |= ADC12SC;                   // start sampling and conversion

        __bis_SR_register(LPM4_bits + GIE);     // LPM4 with interrupts enabled
        __no_operation();

        // Temperature in Celsius
        tempDegC = (float)(((long)(temp) - CALADC12_15V_30C) * (85 - 30)) / (CALADC12_15V_85C - CALADC12_15V_30C) + 30.0f;

        // Temperature in Fahrenheit Tf = (9/5)*Tc + 32
        tempDegF = tempDegC * 9.0f / 5.0f + 32.0f;

        // create string for LCD
        sprintf(temp_st, "%3.0f", tempDegF);

#if(LCDADC)
        // send data to console
        printf("tempDegC = %3.2f   tempDegF = %3.2f   temp = %d\n", tempDegC, tempDegF, temp);
        //fprintf(stdout, "tempDegF = %3.1f   tempDegC = %3.1f\n", tempDegF, tempDegC);

        // build LCD data string
        // these are correct conversion codes, incorrect codes caused several problems
        sprintf(string1, "%3.2f     %3.2f     %d        \n", tempDegC, tempDegF, temp);

        // LCD data display
        LCD_put_string_4_cc(ROW10, COL0, "DEGC      DEGF      TEMP          ", black, white);
        LCD_put_string_4_cc(ROW11, COL0, "----------------------------------", black, white);
        LCD_put_string_4_cc(ROW12, COL0, string1, black, white);
#endif
        __no_operation();                       // if desired, set breakpoint here
    }
}


/***************************************************************************************************************
 *
 * MSP430 ADC12 ISR - for 3 sequential ADC channels (case 32), and 1 single channel (case 6)
 *
 **************************************************************************************************************/
// this ISR deals with two ADC functions: case 6 for single temperature
// and case 32 for sequence of channels: voltage and two other sensors
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector=ADC12_VECTOR
__interrupt void ADC12ISR (void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(ADC12_VECTOR))) ADC12ISR (void)
#else
#error Compiler not supported!
#endif
{
  // dissect ADC12IV and process single, correct interrupt vector, use last channel for a sequence
  // 2nd arg is the range, which is case value in decimal
  // case uses decimal, interrupt vector uses hex
  // example only went to case 34 for ADC12IFG14, corrected here to case 36
  switch(__even_in_range(ADC12IV,36))
  {
  case  0: break;                           // Vector  0:  No interrupt
  case  2: break;                           // Vector  2:  ADC overflow
  case  4: break;                           // Vector  4:  ADC timing overflow
  case  6:                                  // Vector  6:  ADC12IFG0, temperature
      temp = ADC12MEM0;
      __bic_SR_register_on_exit(LPM4_bits); // Exit active CPU
      break;
  case  8: break;                           // Vector  8:  ADC12IFG1
  case 10: break;                           // Vector 10:  ADC12IFG2
  case 12: break;                           // Vector 12:  ADC12IFG3
  case 14: break;                           // Vector 14:  ADC12IFG4
  case 16: break;                           // Vector 16:  ADC12IFG5
  case 18: break;                           // Vector 18:  ADC12IFG6
  case 20: break;                           // Vector 20:  ADC12IFG7
  case 22: break;                           // Vector 22:  ADC12IFG8
  case 24: break;                           // Vector 24:  ADC12IFG9
  case 26: break;                           // Vector 26:  ADC12IFG10
  case 28: break;                           // Vector 28:  ADC12IFG11
  case 30: break;                           // Vector 30:  ADC12IFG12
  case 32:                                  // Vector 32:  ADC12IFG13 - use interrupt case for last channel in sequence
      //ADC_results[i][0] = ADC12MEM10;       // Move A10 results, IFG is cleared, used in 4 channel sequence example for temperature, only 3 channel sequence used here
      ADC_results[i][0] = ADC12MEM11;       // Move A11 results, IFG is cleared
      ADC_results[i][1] = ADC12MEM12;       // Move A12 results, IFG is cleared
      ADC_results[i][2] = ADC12MEM13;       // Move A13 results, IFG is cleared
      __bic_SR_register_on_exit(LPM4_bits); // Exit active CPU, SET BREAKPOINT HERE
      break;
  case 34: break;                           // Vector 34:  ADC12IFG14
  case 36: break;                           // Vector 36:  ADC12IFG15
  default: break;
  }
}

手册中有详细说明。

1) 1) ADC12ON 仅打开和关闭 ADC。 当 ADC 打开时、某些配置位无法置位。

2) 2)使基准电压为2.5V 的位未设置、因此...

3) 3)我在您的代码中找不到它。

4) 4)正确。

5) 5)我不理解问题。 除非您想知道为什么将该常量写入0x001而不是0x0001。 这并不重要、因为它们完全相同。

6) 6) ADCMEM10上没有传感器。 这是为 ADCMCTL10控制的转换存储结果的地方。 输入将是那里选择的任何值。

DS/UG 有时会有很差的描述、这些描述深得难以找到。 尽管总的来说、编写的文档非常好。

3是来自 msp430f5638.h 头文件、与#5是相同的问题。 我不同意0x000与0x0000相同。 在第一种情况下、上半字节未定义。 现在、如果 TI 的内部代码处理这些未定义的上部半字节(在常量中)、那么这是可以的。 这是什么情况发生了、这些细节在哪里详细说明了？

0是整数大小的整数常量。 16位。 0L 是一个长整数常量。 这是非常基本的 C 语言、与 MSP430无关。