[参考译文] TMS320F280039C：ADC 是预期计数的一半

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Other Parts Discussed in Thread: SYSCONFIG

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https://e2e.ti.com/support/microcontrollers/c2000-microcontrollers-group/c2000/f/c2000-microcontrollers-forum/1123569/tms320f280039c-adcs-are-half-of-expected-counts

器件型号：TMS320F280039C
Thread 中讨论的其他器件：SysConfig

您好！

我的 ADC 正在读取预期计数的一半。如果我向 ADC 施加1.5V 电压、则会得到1024而不是2048。我觉得我的缩放比例在某个地方是错误的。

我将此内容添加到了初始化中、因为我看到 SysConfig 为演示项目生成了此内容。

    // asysctl initialization
    // Disables the temperature sensor output to the ADC.
    ASysCtl_disableTemperatureSensor();
    // Set the analog voltage reference selection to internal.
    ASysCtl_setAnalogReferenceInternal( ASYSCTL_VREFHI );
    // Set the internal analog voltage reference selection to 1.65V.
    ASysCtl_setAnalogReference1P65( ASYSCTL_VREFHI );

我还根据需要将电压基准设置为3.3V：

    // Set ADC voltage ref
    ADC_setVREF(adcHandle[0], ADC_REFERENCE_INTERNAL, ADC_REFERENCE_3_3V);
    ADC_setVREF(adcHandle[1], ADC_REFERENCE_INTERNAL, ADC_REFERENCE_3_3V);
    ADC_setVREF(adcHandle[2], ADC_REFERENCE_INTERNAL, ADC_REFERENCE_3_3V);
    ADC_setOffsetTrimAll(ADC_REFERENCE_INTERNAL, ADC_REFERENCE_3_3V);

这是我的 ADC 初始化代码-

void Setup_FastADC()
{
    // Select interrupt source - this will be the last sample converted and therefore trigger the interrupt 1
    ADC_setInterruptSource(ADCC_BASE, ADC_INT_NUMBER1, ADC_DCBUS_SOCNUM);

    // Setup ADCs for PhA - this is triggered based off of counter EPWM1 SOCA (setup below)
    // Sample window must be > 75ns per datasheet, > 90ns for AGPIO per datasheet (at least > 11 SYSCLK cycles to be safe - 91.3ns)
    // Sample window must also be as long as 1 ADC clock cycle (40ns) - input sample window in SysClk cycles (11 cycle = 91.3ns)
    ADC_setupSOC(ADC_PHA_I_BASE, ADC_PHA_I_SOCNUM, ADC_TRIGGER_EPWM1_SOCA, ADC_PHA_I_CHANNEL, ADC_SAMPLE_WINDOW);
    ADC_setInterruptSOCTrigger(ADC_PHA_I_BASE, ADC_PHA_I_SOCNUM, ADC_INT_SOC_TRIGGER_NONE);

    // Configuring PPB in case we have any calibration to do
    // Configure PPB to subtract out any offset
    // PPB is associated with ADCA_SOC1
//    ADC_setupPPB(ADC_PHA_I_BASE, ADC_PHA_I_PPBNUM, ADC_PHA_I_SOCNUM);
//
//    // Write 0 to PPB will disable PPB offset calibration (change 0 to the offset we want if we need)
//    ADC_setPPBCalibrationOffset(ADC_PHA_I_BASE, ADC_PHA_I_PPBNUM, 0);

    // Setup ADCs for PhB - this is triggered based off of counter EPWM1 SOCA (setup below)
    // Sample window must be > 75ns per datasheet, > 90ns for AGPIO per datasheet (at least > 11 SYSCLK cycles to be safe - 91.3ns)
    // Sample window must also be as long as 1 ADC clock cycle (40ns) - input sample window in SysClk cycles (11 cycle = 91.3ns)
    ADC_setupSOC(ADC_PHB_I_BASE, ADC_PHB_I_SOCNUM, ADC_TRIGGER_EPWM1_SOCA, ADC_PHB_I_CHANNEL, ADC_SAMPLE_WINDOW);
    ADC_setInterruptSOCTrigger(ADC_PHB_I_BASE, ADC_PHB_I_SOCNUM, ADC_INT_SOC_TRIGGER_NONE);

//    // Configuring PPB in case we have any calibration to do
//    // Configure PPB to subtract out any offset
//    // PPB is associated with ADCB_SOC1
//    ADC_setupPPB(ADC_PHB_I_BASE, ADC_PHB_I_PPBNUM, ADC_PHB_I_SOCNUM);
//
//    // Write 0 to PPB will disable PPB offset calibration (change 0 to the offset we want if we need)
//    ADC_setPPBCalibrationOffset(ADC_PHB_I_BASE, ADC_PHB_I_PPBNUM, 0);

    // Setup ADCs for PhC - this is triggered based off of counter EPWM1 SOCA (setup below)
    // Sample window must be > 75ns per datasheet, > 90ns for AGPIO per datasheet (at least > 11 SYSCLK cycles to be safe - 91.3ns)
    // Sample window must also be as long as 1 ADC clock cycle (40ns) - input sample window in SysClk cycles (11 cycle = 91.3ns)
    ADC_setupSOC(ADC_PHC_I_BASE, ADC_PHC_I_SOCNUM, ADC_TRIGGER_EPWM1_SOCA, ADC_PHC_I_CHANNEL, ADC_SAMPLE_WINDOW);
    ADC_setInterruptSOCTrigger(ADC_PHC_I_BASE, ADC_PHC_I_SOCNUM, ADC_INT_SOC_TRIGGER_NONE);

//    // Configuring PPB in case we have any calibration to do
//    // Configure PPB to subtract out any offset
//    // PPB is associated with ADCC_SOC1
//    ADC_setupPPB(ADC_PHC_I_BASE, ADC_PHC_I_PPBNUM, ADC_PHC_I_SOCNUM);
//
//    // Write 0 to PPB will disable PPB offset calibration (change 0 to the offset we want if we need)
//    ADC_setPPBCalibrationOffset(ADC_PHC_I_BASE, ADC_PHC_I_PPBNUM, 0);

    // If we need any more PBB's we can copy them from above
    // Setup DCLink sampling -> This will trigger interrupt
    ADC_setupSOC(ADC_DCBUS_BASE, ADC_DCBUS_SOCNUM, ADC_TRIGGER_EPWM1_SOCA, ADC_DCBUS_CHANNEL, ADC_SAMPLE_WINDOW);
    ADC_setInterruptSOCTrigger(ADC_DCBUS_BASE, ADC_DCBUS_SOCNUM, ADC_INT_SOC_TRIGGER_NONE);

}

void Init_ADC()
{
    // asysctl initialization
    // Disables the temperature sensor output to the ADC.
    ASysCtl_disableTemperatureSensor();
    // Set the analog voltage reference selection to internal.
    ASysCtl_setAnalogReferenceInternal( ASYSCTL_VREFHI );
    // Set the internal analog voltage reference selection to 1.65V.
    ASysCtl_setAnalogReference1P65( ASYSCTL_VREFHI );

    // Setup ADC
    // Three ADC modules in this device
    // initialize the ADC handles
    adcHandle[0] = ADCA_BASE;
    adcHandle[1] = ADCB_BASE;
    adcHandle[2] = ADCC_BASE;

    // initialize the ADC results
    adcResult[0] = ADCARESULT_BASE;
    adcResult[1] = ADCBRESULT_BASE;
    adcResult[2] = ADCCRESULT_BASE;

    // Set ADC voltage ref
    ADC_setVREF(adcHandle[0], ADC_REFERENCE_INTERNAL, ADC_REFERENCE_3_3V);
    ADC_setVREF(adcHandle[1], ADC_REFERENCE_INTERNAL, ADC_REFERENCE_3_3V);
    ADC_setVREF(adcHandle[2], ADC_REFERENCE_INTERNAL, ADC_REFERENCE_3_3V);
    ADC_setOffsetTrimAll(ADC_REFERENCE_INTERNAL, ADC_REFERENCE_3_3V);

    // Set main clock scaling factor (60MHz max clock for the ADC module)
    // ADC clock set up for 30 MHz
    ADC_setPrescaler(adcHandle[0], ADC_CLK_DIV_2_0);
    ADC_setPrescaler(adcHandle[1], ADC_CLK_DIV_2_0);
    ADC_setPrescaler(adcHandle[2], ADC_CLK_DIV_2_0);

    // Set the ADC interrupt pulse generation to end of conversion
    ADC_setInterruptPulseMode(adcHandle[0], ADC_PULSE_END_OF_CONV);
    ADC_setInterruptPulseMode(adcHandle[1], ADC_PULSE_END_OF_CONV);
    ADC_setInterruptPulseMode(adcHandle[2], ADC_PULSE_END_OF_CONV);

    // Disables SOC burst mode.
    ADC_disableBurstMode(adcHandle[0]);
    ADC_disableBurstMode(adcHandle[1]);
    ADC_disableBurstMode(adcHandle[2]);

    // Set priority of SOCs
    ADC_setSOCPriority(adcHandle[0], ADC_PRI_ALL_HIPRI);
    ADC_setSOCPriority(adcHandle[1], ADC_PRI_ALL_HIPRI);
    ADC_setSOCPriority(adcHandle[2], ADC_PRI_ALL_HIPRI);

    // Enable ADCs
    ADC_enableConverter(adcHandle[0]);
    ADC_enableConverter(adcHandle[1]);
    ADC_enableConverter(adcHandle[2]);

    // Delay to allow ADCs to power up
    SysCtl_delay(5000U);

    // Setup ADCs for fast samples - A, B, C, DC Link
    Setup_FastADC();

    // Init motor PWM to trigger ADC
    MotorPWM_Init();

    // Enable ADC interrupt - Enables ADC interrupts in group 1 - priority 12
    // Kicks off the fast thread
    Interrupt_clearACKGroup(INTERRUPT_ACK_GROUP1);
    Interrupt_register(INT_ADCC1, &adcC1ISR); // register ISR
}

感谢您的帮助！

3 年多前