Imbus/cm3-bluepill
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uart

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Imbus 2025-07-16 18:00:08 +02:00
parent ed3f82222d
commit 7086e5f9e9
2 changed files with 10 additions and 17 deletions
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10
main.c
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@ -16,7 +16,6 @@ static void gpio_setup(void) {
/* Setup GPIO6 and 7 (in GPIO port A) for LED use. */
gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO12);
}
static void clock_setup(void) {
rcc_clock_setup_pll(&rcc_hse_configs[RCC_CLOCK_HSE8_72MHZ]);
@ -37,14 +36,7 @@ int main(void) {
sys_tick_setup();
usart_setup();
usart_send_blocking(USART1, 'H');
usart_send_blocking(USART1, 'e');
usart_send_blocking(USART1, 'l');
usart_send_blocking(USART1, 'l');
usart_send_blocking(USART1, 'o');
usart_send_blocking(USART1, '\n');
printf("Well hello");
printf("Printf is working!\n");
gpio_clear(GPIOC, GPIO13);
gpio_set(GPIOC, GPIO13);

17
uart.c
View file

@ -5,6 +5,7 @@
#include <libopencm3/stm32/rcc.h>
#include <libopencm3/stm32/usart.h>
#include <stdio.h>
#include <unistd.h>
int _write(int file, char *ptr, int len);
@ -12,7 +13,6 @@ void usart_setup(void) {
/* Setup GPIO pin GPIO_USART1_RE_TX on GPIO port B for transmit. */
gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART1_TX);
/* Setup UART parameters. */
usart_set_baudrate(USART1, 115200);
usart_set_databits(USART1, 8);
usart_set_stopbits(USART1, USART_STOPBITS_1);
@ -20,18 +20,19 @@ void usart_setup(void) {
usart_set_flow_control(USART1, USART_FLOWCONTROL_NONE);
usart_set_mode(USART1, USART_MODE_TX);
/* Finally enable the USART. */
usart_enable(USART1);
}
int _write(int file, char *ptr, int len) {
int i;
if (file == 1) {
for (i = 0; i < len; i++) usart_send_blocking(USART1, ptr[i]);
return i;
if (file == STDOUT_FILENO || file == STDERR_FILENO) {
for (int i = 0; i < len; i++) {
if (ptr[i] == '\n') {
usart_send_blocking(USART1, '\r');
}
usart_send_blocking(USART1, ptr[i]);
}
return len;
}
errno = EIO;
return -1;
}