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Dave Sclegel
Dave Sclegel
Associate
February 27, 2018
Question

STM32M4F415 with Connect EVE

  • February 27, 2018
  • 5 replies
  • 1317 views
Posted on February 27, 2018 at 22:32

Hey there,

iam a stundet and try to create a programm to test some Piezo's on some structures.

I have a STM32 Mini M4 F415 and a Connect Eve Display from mikroe.

I want to get the ADC Value of the peak when i push a plate of Piezos.(4 of them)

The i want to sort them with bubble sort and some calculations.

And after that i want to give the calculated adc value to the Display.

I tried some resolutions i saw on youtube and other Internet pages but i dont got the peaks from my adc to my Array[3] and to the Diplay over SPI.

I use the Cube MX to init my Configuration.

The Calc and sort algorithm and code is not the problem , but this connection between ADC and my array with the peaks. And the the connection to the display.

Does anybody has some links or examples? Where i can lern from?

Actually i have 4 ADC Inputs in Contuious mode .

LG

Dave

PS: Sry for my bad english language. Normally i only tried to prog some easy chips and something big like this

    This topic has been closed for replies.

    5 replies

    Andrew Neil
    Andrew Neil
    Super User
    February 28, 2018
    Posted on February 28, 2018 at 12:42

    As always, you need to break the problem down into its distinct parts.

    Don't try to solve the whole thing in one go!

    Getting the samples from the ADC is a separate problem from displaying stuff on an LCD.

    The Calc and sort algorithm and code is not the problem

    How do you know that?

    A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
    Dave Sclegel
    Dave SclegelAuthor
    Associate
    February 28, 2018
    Posted on February 28, 2018 at 14:29

    OK ,

    my first problem is to get the peak value from the piezo sensor when i touch the plate where the piezo is located.

    How can i configure the ADC Inputs that they record the peak and not all the time when no high input comes?

    And after that : Is it possible to get the Values from the ADC to a array?

    I tried this following lines.

     First i configured in CubeMX the ADC in

    Scan Vonversion Mode to Enabled

    Continuous Mode to Enabled

    Number of Conversations 4

    And Sampling times to 15 Cycles.(12 bits Resolution)

    Added some arrays

    uint32_t  

    adc_buf

    [

    4

    ]

    ,

    adc_sensor

    [

    4

    ],adc_display[4]

    ;

    void

    HAL_ADC_ConvCpltCallback

    (

    ADC_HandleTypeDef*

    hadc

    )

    {

    for

    (

    int

    i

    =

    0

    ;

    i

    <

    4

    ;

    i

    ++

    )

    {

      

    adc_sensor

    [

    i

    ]

    =

    adc_buf

    [

    i

    ]

    ;

      

    // From Buf to ADC_Sensor

    }

    }

    After that

    main

    (

    )

    {

      ...

           MX_GPIO_Init();

           MX_DMA_Init();

           MX_ADC1_Init();

           MX_SPI1_Init();

       

         HAL_ADC_Start_DMA

    (

    &

    hadc1

    ,

    (

    uint32_t *

    )

    adc_buf

    ,

    4

    )

    ;

        

    while

    (

    1

    )

            

    {

                adc

    _display

    [

    0

    ]

    =

    adc_sensor

    [

    0

    ]

    ;

                adc

    _display

    [

    1

    ]

    =

    adc_sensor

    [

    1

    ]

    ;

                adc_display

    [

    2

    ]

    =

    adc_sensor

    [

    2

    ]

    ;

                adc_display

    [

    3

    ]

    =

    adc_sensor

    [

    3

    ]

    ;

               

    HAL_Delay

    (

    1000

    )

    ;

            

    }

    }

    Should be this not a correct code to get the values from the ADC Sensors on Channel 0-3 ?

    Andrew Neil
    Andrew Neil
    Super User
    February 28, 2018
    Posted on February 28, 2018 at 15:11

    Dave Sclegel wrote:

    How can i configure the ADC Inputs that they record the peak and not all the time

    You start by studying the Reference Manual for the chip - look at the ADC section for a description of the available operating modes, and see which most closely matches your requirement.

    I've never had cause to look for it, but I don't recall seeing a 'peak-detect' mode. But you need to check for yourself.

    If there is no suitable mode, you have 2 choices:

    • Sample continuously, and do the peak-detect in software;
    • Add external peak-detect hardware.
    A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
    Dave Sclegel
    Dave SclegelAuthor
    Associate
    March 1, 2018
    Posted on March 01, 2018 at 11:15

    Ok, does this chip or STm32 have something like sample and hold?

    I know a Arduino has on its analog inputs something like this.

    LG

    Andrew Neil
    Andrew Neil
    Super User
    March 1, 2018
    Posted on March 01, 2018 at 11:19

    See

    https://community.st.com/0D50X00009XkWdWSAV

    - have you actually looked in the

    documentation to find out?

    Dave Sclegel wrote:

    I know a Arduino has on its analog inputs something like this.

    Arduino is open-source - so take a look to see how they do it ...

    A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
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