undefined reference to `__nop'

[MarkEvens]

in function hx711_delay_us': undefined reference to __nop'

I have put this lib in stm32 project Drivers folder and given path properly

Having this issue can guide me on what I am doing wrong

[Gocql022]

My English no so good, please translate the following text, I think it may help you(Chinese to English).
undefined reference to __nop'意味着没有定义__nop()函数，我今天也遇到了这个问题，去网上查了下这个函数的含义，得知这是一个什么都不做只会延时（时间极其短暂）的函数，因此只需在引用了__nop()的文件上面如此定义这个函数：
void __nop()
{
;
}
这样一个__nop()函数就定义好了，希望能帮到你😊