STM32通过UART向串口发送值

Question

I'm using potentiometer to control servo motor. I want to send the servo angle value to serial port via UART. First, i was getting unknown characters. Now, it prints "Servo: 0 " everytime but i'm changing the value.

 uint32_t potadc; uint32_t servopot; char str[32]; int size_len = sprintf (str, "Servo : %lu\\n", servopot, 0xFFFF); while { servopot = potadc/6; HAL_UART_Transmit (&huart2, (uint8_t *)str, size_len, HAL_MAX_DELAY); HAL_Delay(1000); }

Answer 1

sprintf has to be inside the loop otherwise it will be executed only once before entering the loop/.

int size_len;

while(1) {
    servopot = potadc/6;
    size_len = sprintf (str, "Servo : %u\n", servopot);
    HAL_UART_Transmit (&huart2, (uint8_t *)str, size_len, HAL_MAX_DELAY);
    HAL_Delay(1000);        
}

Answer 2

I moved the

 int size_len = sprintf (str, "Servo : %lu\\n", servopot, 0xFFFF);

code to the loop, it worked. Thanks everyone who tried to answer.