topic Re: hello, I'm having problems with a K70 ADC channel. in Kinetis Microcontrollers

hello, I'm having problems with a K70 ADC channel.

jeffclawson — Mon, 02 Nov 2020 13:28:24 GMT

I'm having problems when I use the ADC0_SOURCE__AD5B channel in the below structure.

The code works if I use the ADC0_SOURCE_AD3. I know that the muxsel must be set to B for the AD5B channel.

Is there any known issues with this channel?

Re: hello, I'm having problems with a K70 ADC channel.

Alice_Yang — Thu, 24 Mar 2016 03:55:49 GMT

Hello Jeff,

- When you use the AD5B channel, please show us the ADC channel initialize code ,

the pin initialize code .

- Also please check whether it is right about the related registers .

- Then please be sure which pin do you used ?

Hope it helps

Alice

Re: hello, I'm having problems with a K70 ADC channel.

jeffclawson — Mon, 28 Mar 2016 20:08:02 GMT

Alice,

Thanks for your response, I was out of the office on Thursday and Friday.

I've attached the two files used for ADC code.

Re: hello, I'm having problems with a K70 ADC channel.

jeffclawson — Tue, 29 Mar 2016 15:07:48 GMT

I got the code to work but I shouldn't have had to add the code that I did.

I added the following code to the end of the void CADCModule::ADC_ReadChannel(BYTE channelIndex) function.

if (channelIndex == I_SENSE_AC_INDEX)

{

fclose(m_ADC0);

InitADCModule_ADC0();

}

Without this code the next measured channel on the ADC0 channel would fail to open.

Why does the ADC0_SOURCE_AD5B channel measurement cause the next channel to fail to open.

case VOLT_SENSE_5V_INDEX:

ADC_Channel_PTR = fopen(ADC0 "5V Voltage Sensor", (const char *)&ADC0_VOLT_SENSE_5V_Channel);

channel = 0;

break;

All the other channels work as they should.

Re: hello, I'm having problems with a K70 ADC channel.

kerryzhou — Wed, 30 Mar 2016 06:53:03 GMT

Hi Jeff,

Could you tell me what the fopen function retrun when you call ADC_ReadChannel, channelIndex= I_SENSE_AC_INDEX in your code?

What the ADC_Channel_PTR data value?

void CADCModule::ADC_ReadChannel(BYTE channelIndex)
{ 
    MQX_FILE_PTR ADC_Channel_PTR;  //
    numBytesRead = 0;
    BYTE channel;
    switch (channelIndex)
    {
    case I_SENSE_3_3V_INDEX:
        ADC_Channel_PTR = fopen(ADC0 "3V Current Sensor", (const char *)&ADC0_I_SENSE_3_3V_Channel);
        channel = 0;
        break;
    case I_SENSE_5V_INDEX:
        ADC_Channel_PTR = fopen(ADC1 "5V Current Sensor", (const char *)&ADC1_I_SENSE_5V_Channel);
        channel = 1;
        break;
    case I_SENSE_AC_INDEX:
        ADC_Channel_PTR = fopen(ADC0 "AC Current Sensor", (const char *)&ADC0_I_SENSE_AC_Channel);
        channel = 0;
        break;
    case VOLT_SENSE_5V_INDEX:
        ADC_Channel_PTR = fopen(ADC0 "5V Voltage Sensor", (const char *)&ADC0_VOLT_SENSE_5V_Channel);
        channel = 0;
        break;
    case VOLT_SENSE_3_3V_INDEX:
        ADC_Channel_PTR = fopen(ADC1 "3V Voltage Sensor", (const char *)&ADC1_VOLT_SENSE_3_3V_Channel);
        channel = 1;
        break;
    case TEMP_SENSE_INDEX:
        ADC_Channel_PTR = fopen(ADC1 "Temp Sensor", (const char *)&ADC1_TEMP_SENSE_Channel);
        channel = 1;
        break;
    default:
        ADC_Channel_PTR = NULL;
        channel = 0;
        break;
    }
    if (ADC_Channel_PTR == NULL)
    {
        printf("Cannot open ADC Channel\n");
        fclose(ADC_Channel_PTR);
        if (channel == 0)
        {
            fclose(m_ADC0);
            InitADCModule_ADC0();
        }
        else if (channel == 1)
        {
            fclose(m_ADC1);
            InitADCModule_ADC1();
        }
    }

Please do the debug step by step in your code when you are calling ADC_ReadChannel, whether other ADC channel will make ADC_Channel_PTR == NULL? I find your code when ADC_Channel_PTR == NULL, then will do ADC channel fclose and init.

Have a great day,
Jingjing

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Re: hello, I'm having problems with a K70 ADC channel.

jeffclawson — Wed, 30 Mar 2016 12:23:21 GMT

The above shows a break point set when the channel fails the fopen. ADC_Channel_PTR = _vector_table(0x0):

Here is the same break point but this is for the working case. ADC_Channel_PTR = 0x72183C30

The only difference between the two cases is that the failed case does not execute the below code:

if (channelIndex == I_SENSE_AC_INDEX)

{

fclose(m_ADC0);

InitADCModule_ADC0();

}

Re: hello, I'm having problems with a K70 ADC channel.

kerryzhou — Thu, 31 Mar 2016 02:05:01 GMT

Hi Jeff,

I find a disorder in your header file:

// 3.3V Current Sensor const ADC_INIT_CHANNEL_STRUCT ADC0_I_SENSE_3_3V_Channel = { ADC0_SOURCE_AD3, // 3.3V Current Sensor,physical ADC ADC_CHANNEL_MEASURE_ONCE | ADC_CHANNEL_START_NOW, NUM_SAMPLES_IN_ONE_RUN, // number of samples in one run sequence START_OFFSET, // PERIOD, // period in us SCALE_RANGE, // scale range of result (not used now) CIRCULAR_BUFFER_SIZE, // circular buffer size (sample count) ADC_PDB_TRIGGER, // logical trigger ID that starts this ADC channel NULL, // no lwevent used 0 // lwevent bits };

// 5V Voltage Sensor const ADC_INIT_CHANNEL_STRUCT ADC0_VOLT_SENSE_5V_Channel = { ADC0_SOURCE_AD1, // 3.3V Voltage Sensor,physical ADC channel ADC_CHANNEL_MEASURE_ONCE | ADC_CHANNEL_START_NOW, NUM_SAMPLES_IN_ONE_RUN, // number of samples in one run sequence PERIOD, // period in us START_OFFSET, // SCALE_RANGE, // scale range of result (not used now) CIRCULAR_BUFFER_SIZE, // circular buffer size (sample count) ADC_PDB_TRIGGER, // logical trigger ID that starts this ADC channel NULL, // no lwevent used 0 // lwevent bits };

// AC Current Sensor const ADC_INIT_CHANNEL_STRUCT ADC0_I_SENSE_AC_Channel = { #if 0 ADC0_SOURCE_AD5B, // not working // AC current Sensor,physical ADC channel #else ADC0_SOURCE_AD3, // !!!!! using working channel here even thou it is not the correct channel.!!!!! #endif ADC_CHANNEL_MEASURE_ONCE | ADC_CHANNEL_START_NOW, NUM_SAMPLES_IN_ONE_RUN, // number of samples in one run sequence START_OFFSET, // PERIOD, // period in us SCALE_RANGE, // scale range of result (not used now) CIRCULAR_BUFFER_SIZE, // circular buffer size (sample count) ADC_PDB_TRIGGER, // logical trigger ID that starts this ADC channel NULL, // no lwevent used 0 // lwevent bits };

Why ADC0_VOLT_SENSE_5V_Channel, the defination of PERIOD, START_OFFSET is not like other channel?

Whether it should be :

// 5V Voltage Sensor

const ADC_INIT_CHANNEL_STRUCT ADC0_VOLT_SENSE_5V_Channel =

{

ADC0_SOURCE_AD1, // 3.3V Voltage Sensor,physical ADC channel

ADC_CHANNEL_MEASURE_ONCE | ADC_CHANNEL_START_NOW,

NUM_SAMPLES_IN_ONE_RUN, // number of samples in one run sequ

START_OFFSET, //

PERIOD, // period in us

SCALE_RANGE, // scale range of result (not used now)

CIRCULAR_BUFFER_SIZE, // circular buffer size (sample count)

ADC_PDB_TRIGGER, // logical trigger ID that starts this ADC channel

NULL, // no lwevent used

0 // lwevent bits

};

I am not familiar with your mqx code, I just find the definiation has the difference, I don't know whether it has problem when you call : VOLT_SENSE_5V_INDEX

Besides, please also check the PORTx_PCRn[MUX], when the problem happens.

Have a great day,
Jingjing