# How to use the xprintf function on stm32f429?

can you help me? I'm a new one. How to use this ''xprintf''? I have connected my uart2, but it's no use. Should I choose the MicroLib in keil? Or rewrite the _wrtie() and _read()? I didn't use the semihostings(use #program to removed the semihostings mode), Thank you.

P.s. My ide is keil5, and use the stm32f429 to do it. And I downloaded xprintf.c/.h from https://github.com/tmk/elm-chan_xprintf/blob/master/xprintf.c

• I have no ideas to solve this problem, please provide some helps or informations, thanks all. – Kenneth Dec 13 '16 at 12:24

Register the functions that send\receive one character to UART.

Read the last paragraph here. Download the Examples and take a look at the stm32 folder. http://elm-chan.org/fsw/strf/xprintf.html

Here's what I did using the HAL drivers and STM32Cube generated project.

xdev_out(uart_putc);
xdev_in(uart_getc);

void uart_putc(char c){
HAL_UART_Transmit(&huart2, (uint8_t*)&c, 1, 0xFFFF);
}
void uart_getc(char c){
HAL_UART_Receive(&huart2, (uint8_t*)&c, 1, 0xFFFF);
}