I've been playing with the fsl_uart component, and started with my FRDM-K64F. Using KSDK + PEx + MQX, I was able to confirm operation of UART3 with some simple loopback test code.
Now I've moved on to the FRDM-K22F. Also using a similar configuration with KSDK + PEx + MQX, I have not been able to get my loopback code working. I believe the only difference is that on the K22 board, I am using UART2 (PTD2/PTD3). The specific problem I am having is that UART_DRV_SendDataBlocking hangs because the inner call to UART_DRV_StartSendData hangs. I am unable to step into UART_DRV_StartSendData. My initial impression is that something is misconfigured, resulting in an invalid call (e.g. wrong memory address).
If I pause execution at random times, it seems that the code is always stuck in the idle task.
I've attached my project in case anyone at FSL or elsewhere has time to import it and try it out to confirm the behavior, and hopefully offer advice for followup debugging steps.
Original Attachment has been moved to: RobotAxis.zip