Problem with tm1637_delay_us()

[cypamigon]

Hi,

Thanks for the library, it works great !
However, I had a little problem with the function "tm1637_delay_us()". Firstly, the instructions "__nop();" were not recognized by the compiler. I've tried with asm("nop"); instead. I could flash the program but unfortunately it didn't worked.
I've tried to use a hardware timer to create the delay and it worked !

If someone, is facing the same issue, here is the way to achieve it :

• Configure the hardware timer in CubeMX. You must change the prescaler in order to create a 1 MHz timer (to achieve a us clock period). In my case, I've used a F401RE Nucleo Board with a 84 MHz clock so I set the prescaler value to 84-1.
• In the CubeMX project manager , tick "Generate peripheral initialization as a pair of '.c/.h' files per peripheral" so that you can use timer stuff in "tm1637.c" file.
• In "tm1637.c", add :

#include "tim.h"

and change :

void tm1637_delay_us(uint8_t delay)
{
     while (delay > 0)
     {
        delay--;
        __nop();__nop();__nop();__nop();
     }
}

by

void tm1637_delay_us(uint8_t delay)
{
    HAL_TIM_Base_Start(&htim4);
    __HAL_TIM_SET_COUNTER(&htim4,0);  // set the counter value a 0
    while (__HAL_TIM_GET_COUNTER(&htim4) < delay);  // wait for the counter to reach the us input in the parameter
    HAL_TIM_Base_Stop(&htim4);
}

Adapt the previous code with the timer you are using (in my case, I was using TIMER 4)

[nimaltd]

Hello. I have tried with keil and it works "__nop()". and yes, hardware timer is better.

[asking23]

how to get nop recognized by stm32cube ide ? without any modification ?

[nimaltd]

@asking23 i think in upper case __NOP()

[Mrezapbs]

I Had the same issue. __nop() couldn't get recognized by stm32cube ide. So I changed to capital Letters __NOP().It compiled successfully But the Segments didn't light up.
The reason was I had configured my clock to 72 Mhz and __NOP() is working based on clock frequency. I changed it to 8 Mhz ....
Worked Perfectly. Thank you for such a clean and beautiful Library.

[nimaltd]

@Mrezapbs thanks for your response