I have transmited (AT\r\n) to sim 7000 with HAL_UART_Transmit(uart,temp,size,time). but i dont get (OK) in HAL_UART_Receive_IT() from sim 7000. anyone can help me ?

[Jfar.1]

my code to transmite to sim 7000

--> HAL_UART_Transmit(gsm_device.uart, temp, size, 250);

and my code to receive

-->

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)

{

   if(huart->Instance == huart1.Instance) {

       // receive next character

       HAL_UART_Receive_IT(&huart1, &uart_rx_buffer, 1);

   }

}