[参考译文] TM4C123GH6PM：ADC 比较器中断

#define ADC_SEQUENCER3_LENGTH 1
#define ADC_SEQUENCER2_LENGTH 4
#define ADC_SEQUENCER1_LENGTH 4
#define ADC_SEQUENCER0_LENGTH 8

#define VOLTAGE_CALIBRATION_FACTOR 1.008

int ulTemp_ValueC;
uint32_t TempBuf[ADC_SEQUENCER3_LENGTH];                        // SS3 has the size of 1 sample
uint32_t VoltBuf[ADC_SEQUENCER2_LENGTH];                        // SS2 has the size of 4 samples

int tempC;
int tempF;
uint32_t voltage;
int32_t VoltIntegerPart;
int32_t VoltFractionPart;

void InitUART(void){
    // Initialize the UART.

    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);
    SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);
    GPIOPinConfigure(GPIO_PA0_U0RX);
    GPIOPinConfigure(GPIO_PA1_U0TX);
    GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1);
    UARTClockSourceSet(UART0_BASE, UART_CLOCK_PIOSC);
    UARTStdioConfig(0, 115200,  16000000);
}

void InitADC(void){
  SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOE);
  GPIOPinTypeADC(GPIO_PORTE_BASE, GPIO_PIN_3);                                                          // Configure PE3 as an ADC input
  SysCtlPeripheralEnable(SYSCTL_PERIPH_ADC0);                                                           // Enable the ADC0 peripheral
  ADCHardwareOversampleConfigure(ADC0_BASE,32);                                                         // Set the auto average to 64

  // Configure sequence 3 for internal temperature sensor
  ADCSequenceDisable(ADC0_BASE, 3); // Disable sequence 3
  ADCSequenceStepConfigure(ADC0_BASE, 3, 0, ADC_CTL_TS | ADC_CTL_IE | ADC_CTL_END); // Set up the last step and start an interrupt when the conversion is over
  ADCSequenceEnable(ADC0_BASE, 3); // Enable the sequence again
  ADCSequenceConfigure(ADC0_BASE, 3, ADC_TRIGGER_PROCESSOR, 1); // Configure sequence 3, Priority must be 1 or 0 if ADC_TRIGGER_ALWAYS is used by another sequence
  ADCIntClear(ADC0_BASE, 3); // Clear the interrupt flag

  // Configure sequence 2 for voltage measurement on AIN0 (PE)
  ADCSequenceDisable(ADC0_BASE, 2);                                                                     // Disable sequence 2
  ADCSequenceStepConfigure(ADC0_BASE, 2, 0, ADC_CTL_CH0 | ADC_CTL_CMP0);
  ADCSequenceStepConfigure(ADC0_BASE, 2, 1, ADC_CTL_CH0);
  ADCSequenceStepConfigure(ADC0_BASE, 2, 2, ADC_CTL_CH0);
  ADCSequenceStepConfigure(ADC0_BASE, 2, 3, ADC_CTL_CH0 | ADC_CTL_IE | ADC_CTL_END);                     // Set up the last step and start an interrupt when the conversion is over
  ADCSequenceEnable(ADC0_BASE, 2);                                                                       // Enable the sequence again
  ADCSequenceConfigure(ADC0_BASE, 2, ADC_TRIGGER_ALWAYS, 3);                          // Configure sequence 2
  IntPrioritySet(INT_ADC0SS2, 0);
//  ADCIntEnable(ADC0_BASE, 2);
  ADCIntEnableEx(ADC0_BASE, ADC_INT_DCON_SS2);
  ADCIntClear(ADC0_BASE, 2);                                                                             // Clear the interrupt flag


  // Configure the ADC comparator
  ADCComparatorConfigure(ADC0_BASE, 0, ADC_COMP_INT_MID_ONCE);
  ADCComparatorRegionSet(ADC0_BASE, 0, 136, 4095); // Set the comparator region (136 corresponds to 0.11V)
  ADCComparatorReset(ADC0_BASE, 0, true, true); // Reset the comparator
  ADCComparatorIntEnable(ADC0_BASE, 2); // Enable the comparator interrupt

  IntEnable(INT_ADC0SS2); // Enable the ADC sequence 2 interrupt in the NVIC
  IntMasterEnable();
}

void InitGPIO(void) {
    // Enable the GPIO port for the LED (PF2)
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOF);
    GPIOPinTypeGPIOOutput(GPIO_PORTF_BASE, GPIO_PIN_1); // Configure PF2 as an output
    GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_1, 0); // Initialize the LED to be off
}


int GetInternalTemp(void){
    ADCProcessorTrigger(ADC0_BASE, 3);                                 // Trigger the ADC conversion process.
    while(!ADCIntStatus(ADC0_BASE, 3, false)) {}                       // Wait for the interrupt flag to get set
    ADCIntClear(ADC0_BASE, 3);                                         // Clear the interrupt flag
    ADCSequenceDataGet(ADC0_BASE, 3, TempBuf);                     // Get the actual data samples from ADC0 sequencer 3

    // Convert the value to temperature
    // TEMP = 147.5 - ((75 * (VREFP - VREFN) * ADCVALUE) / 4096)
    // 3.3V * 10 * 75 = 2475 //13.3.6 of the TM4C123GH6PM datasheet
    ulTemp_ValueC = (1475 -((2475 * TempBuf[0])) / 4096)/10;

    return ulTemp_ValueC;
}

uint32_t GetVoltage(void){
    uint32_t ulADC0Value[1];

    ADCProcessorTrigger(ADC0_BASE, 2); // Trigger the ADC conversion process
    while(!ADCIntStatus(ADC0_BASE, 2, false)) {} // Wait for the interrupt flag to get set
    ADCIntClear(ADC0_BASE, 2); // Clear the interrupt flag
    ADCSequenceDataGet(ADC0_BASE, 2, VoltBuf); // Get the actual data samples from ADC0 sequencer 2

    ulADC0Value[0] = (VoltBuf[0] + VoltBuf[1] + VoltBuf[2] + VoltBuf[3] + 2)/4;
    return ulADC0Value[0];
}

void IntToFloat(uint32_t intV){
    float fVoltage;

    fVoltage = (intV * 3.3)/4096 * VOLTAGE_CALIBRATION_FACTOR;
    VoltIntegerPart = (int32_t) fVoltage;
    VoltFractionPart = (int32_t) (fVoltage * 1000.0f);
    VoltFractionPart = VoltFractionPart - (VoltIntegerPart * 1000);
    if (VoltFractionPart < 0){
        VoltFractionPart *= -1;
    }
}

void ADC0Seq2Handler(void){
 //   IntMasterDisable();
 //   uint32_t ulStatus = ADCIntStatus(ADC0_BASE, 2, true);
 //   uint32_t comparatorStatus = ADCComparatorIntStatus(ADC0_BASE);
    uint32_t status;

    status = ADCComparatorIntStatus(ADC0_BASE);


    ADCComparatorIntClear(ADC0_BASE, status);

    if ((ADCSequenceDataGet(ADC0_BASE, 2, VoltBuf) >= 136) & status) {
        GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_1, GPIO_PIN_1);
    }
    if ((ADCSequenceDataGet(ADC0_BASE, 2, VoltBuf) < 136) & status) {
        GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_1, 0);
    }
}

void main(void) {
    SysCtlClockSet(SYSCTL_SYSDIV_2_5 | SYSCTL_USE_PLL | SYSCTL_OSC_MAIN | SYSCTL_XTAL_16MHZ); // System clock: 16*12.5/2.5 = 80MHz (MAX)

    InitGPIO(); //// change later
    InitADC();
    InitUART();
    
    while(1){
        tempC = GetInternalTemp();
        tempF = (1.8 * ulTemp_ValueC) + 32;                            // Celsius to Fahrenheit

        voltage = GetVoltage();
        IntToFloat(voltage);
        UARTprintf("Voltage = %3d.%03dV\n", VoltIntegerPart, VoltFractionPart);
    
        UARTprintf("Temperature = %3d°C / %3d°F\n", tempC, tempF);
        SysCtlDelay(SysCtlClockGet() / 3); // Delay for about 2 seconds
    }
}