Retarget IO API Reference

group group_board_libs



UART baud rate.


Defining this macro enables conversion of line feed (LF) into carriage return followed by line feed (CR & LF) on the output direction (STDOUT).

You can define this macro through the DEFINES variable in the application Makefile.


cy_rslt_t cy_retarget_io_init(cyhal_gpio_t tx, cyhal_gpio_t rx, uint32_t baudrate)

Initialization function for redirecting low level IO commands to allow sending messages over a UART interface.

This will setup the communication interface to allow using printf and related functions.

In an RTOS environment, this function must be called after the RTOS has been initialized.

  • tx – UART TX pin

  • rx – UART RX pin

  • baudrate – UART baudrate


CY_RSLT_SUCCESS if successfully initialized, else an error about what went wrong

void cy_retarget_io_deinit(void)

Releases the UART interface allowing it to be used for other purposes.

After calling this, printf and related functions will no longer work.


cyhal_uart_t cy_retarget_io_uart_obj

UART HAL object used by this library.