cancel
Showing results for 
Search instead for 
Did you mean: 

PSoC 4

bojec_3707286
New Contributor

Hello friends,

This is first time that i wrote question on community , pls understand and let me know if there is something not enough

I am testing an ADC with PSoc 4 pioneer Kit ( CY8CKIT-042 ) and i think measuring the value is successful, but i can't print float to UART

first i'll add my code

#include "project.h"

#include "stdio.h"

float32 adout ;

uint32 channel ;

int16 output;

float32 vo ;

char arr[20] ;

char vo_arr[20];

int main(void)

{

    CyGlobalIntEnable; /* Enable global interrupts. */

    UART_Start();

    UART_UartPutString( " ADC TEST START ! \n" );

   

    ADC_Start();

    ADC_StartConvert();

  

    for(;;)

   

    {

            if( ADC_IsEndConversion(ADC_RETURN_STATUS) == 1)

            {

                output = ADC_GetResult16(channel);

                sprintf(arr, "ADout : %d\r\n" , output );

                UART_UartPutString(arr);

               

                vo = ADC_CountsTo_Volts(channel, output);

                sprintf(vo_arr, "Vout : %f\r\n" , vo );

                UART_UartPutString(vo_arr);

               

                CyDelay(2000);

               

            }

    }

}

This code gives me this outuput on the monitorSerial_Mon_SC1.PNG

So i tried Debug and check the variable , and add some screenshot below

output_conver_done.pngVO_convert_Done.pngoutput_array.png

VO_Db_SC_Arr.png

I think everything is perferct except, putstring(float) , what should i have to do ?

0 Likes
1 Solution
MotooTanaka
Esteemed Contributor

Hi,

I usually use following method to print float value in MCU program

======

            sprintf(str, "(int format) %d.%02d  ", (int)fvalue, ((int)(fvalue * 100.0 + 0.5))%100) ;

            UART_UartPutString(str) ;

======

But in the community someone taught us that there is a linker flag for floating format

Use_newlib-nano_Float.JPG

So I tried with following program

=======================

#include "project.h"

#include <stdio.h>

char str[128] ; /* print buffer */

int main(void)

{

    float32 fvalue ;

   

    CyGlobalIntEnable; /* Enable global interrupts. */

    UART_Start() ;

   

    sprintf(str, "Float Format Test (%s %s)\n", __DATE__, __TIME__) ;

    UART_UartPutString(str) ;

    for(;;)

    {

        for (fvalue = 0.0 ; fvalue < 10.0 ; fvalue += 0.01) {

            sprintf(str, "(int format) %d.%02d  ", (int)fvalue, ((int)(fvalue * 100.0 + 0.5))%100) ;

            UART_UartPutString(str) ;

            sprintf(str, "(float format): %.2f\r\n", fvalue) ;

            UART_UartPutString(str) ;

            CyDelay(1000) ;

        }

    }

}

=======================

With "Use newlib-nano Floating Formatting = False",

Naturally the result was

without_float_format_option.JPG

Then I tried with "Use newlib-nano Floating Formatting = True"

Linker_float_option_yes.JPG

The result was

with_float_format_option.JPG

First the good news was that when fvalue = 0.0, yes it printed "0.00".

Second the bad news was that when fvalue = 0.01, program crashed and ran to exception.

Probably I was missing some other necessary step(s) to make floating point work,

but since my usual method is serving me enough, I resigned here.

So for my conclusion, it's safe using the method I wrote at the beginning.

==========

sprintf(str, "(int format) %d.%02d  ", (int)fvalue, ((int)(fvalue * 100.0 + 0.5))%100) ;

UART_UartPutString(str) ;

==========

moto

View solution in original post

3 Replies
MotooTanaka
Esteemed Contributor

Hi,

I usually use following method to print float value in MCU program

======

            sprintf(str, "(int format) %d.%02d  ", (int)fvalue, ((int)(fvalue * 100.0 + 0.5))%100) ;

            UART_UartPutString(str) ;

======

But in the community someone taught us that there is a linker flag for floating format

Use_newlib-nano_Float.JPG

So I tried with following program

=======================

#include "project.h"

#include <stdio.h>

char str[128] ; /* print buffer */

int main(void)

{

    float32 fvalue ;

   

    CyGlobalIntEnable; /* Enable global interrupts. */

    UART_Start() ;

   

    sprintf(str, "Float Format Test (%s %s)\n", __DATE__, __TIME__) ;

    UART_UartPutString(str) ;

    for(;;)

    {

        for (fvalue = 0.0 ; fvalue < 10.0 ; fvalue += 0.01) {

            sprintf(str, "(int format) %d.%02d  ", (int)fvalue, ((int)(fvalue * 100.0 + 0.5))%100) ;

            UART_UartPutString(str) ;

            sprintf(str, "(float format): %.2f\r\n", fvalue) ;

            UART_UartPutString(str) ;

            CyDelay(1000) ;

        }

    }

}

=======================

With "Use newlib-nano Floating Formatting = False",

Naturally the result was

without_float_format_option.JPG

Then I tried with "Use newlib-nano Floating Formatting = True"

Linker_float_option_yes.JPG

The result was

with_float_format_option.JPG

First the good news was that when fvalue = 0.0, yes it printed "0.00".

Second the bad news was that when fvalue = 0.01, program crashed and ran to exception.

Probably I was missing some other necessary step(s) to make floating point work,

but since my usual method is serving me enough, I resigned here.

So for my conclusion, it's safe using the method I wrote at the beginning.

==========

sprintf(str, "(int format) %d.%02d  ", (int)fvalue, ((int)(fvalue * 100.0 + 0.5))%100) ;

UART_UartPutString(str) ;

==========

moto

View solution in original post

MotooTanaka
Esteemed Contributor

Hi,

I found following two threads

https://community.cypress.com/message/44036#44036

https://community.cypress.com/thread/31761?start=0&tstart=0

So I did

(1) Linker option

build_setting_linker_OK.JPG

(2) Linker Command

linker_command_line.JPG

(3) Expand heap

Edit Generated_Source / cyfitter.h

CYDEV_HEAP_SIZE from 0x80 -> 0x200

cyfitter_heap.JPG

Then the result was

working_log.JPG

So for the first time, I could make "%f" work.

(Although I'd rather stick with int format method)

moto

0 Likes
bojec_3707286
New Contributor

Hello TanaKa

I really appreciate for your reply, your solutions worked for me

but for me , basic option for "Use newlib-nano Floating Formatting was false , and i tried to change it to true , mcu also goes to crash as your one does,

i think your sprintf argument will be best fit for me,

Thank you very much,

Regard Bongjin,

0 Likes