EMTime/libopencm3
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Usart baud rate setting function now uses the new apb1 and apb2 frequency variables. And calculates the full BRR value.

Browse Source
This commit is contained in:
Piotr Esden-Tempski
2011-03-11 19:50:44 -08:00
parent 3d20f37b27
commit 1f3e431527
2 changed files with 53 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

42
examples/stm32/stm32-h103/usart/usart.c
View File

@@ -26,15 +26,45 @@ void clock_setup(void)
rcc_clock_setup_in_hse_8mhz_out_72mhz();
/* Enable GPIOC clock. */
rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPCEN);
rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPAEN | RCC_APB2ENR_IOPBEN | RCC_APB2ENR_IOPCEN);
/* Enable clocks for GPIO port B (for GPIO_USART3_TX) and USART3. */
rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPBEN);
rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_USART3EN);
rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_USART1EN);
rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_USART2EN | RCC_APB1ENR_USART3EN);
}
void usart_setup(void)
{
/* Setup GPIO pin GPIO_USART1_TX. */
gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ,
GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART1_TX);
/* Setup UART parameters. */
usart_set_baudrate(USART1, 38400);
usart_set_databits(USART1, 8);
usart_set_stopbits(USART1, USART_STOPBITS_1);
usart_set_mode(USART1, USART_MODE_TX);
usart_set_parity(USART1, USART_PARITY_NONE);
usart_set_flow_control(USART1, USART_FLOWCONTROL_NONE);
/* Finally enable the USART. */
usart_enable(USART1);
/* Setup GPIO pin GPIO_USART2_TX. */
gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ,
GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART2_TX);
/* Setup UART parameters. */
usart_set_baudrate(USART2, 38400);
usart_set_databits(USART2, 8);
usart_set_stopbits(USART2, USART_STOPBITS_1);
usart_set_mode(USART2, USART_MODE_TX);
usart_set_parity(USART2, USART_PARITY_NONE);
usart_set_flow_control(USART2, USART_FLOWCONTROL_NONE);
/* Finally enable the USART. */
usart_enable(USART2);
/* Setup GPIO pin GPIO_USART3_TX/GPIO10 on GPIO port B for transmit. */
gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_50_MHZ,
GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART3_TX);
@@ -69,9 +99,15 @@ int main(void)
/* Blink the LED (PC12) on the board with every transmitted byte. */
while (1) {
gpio_toggle(GPIOC, GPIO12); /* LED on/off */
usart_send_blocking(USART1, c + '0'); /* USART1: Send byte. */
usart_send_blocking(USART2, c + '0'); /* USART2: Send byte. */
usart_send_blocking(USART3, c + '0'); /* USART3: Send byte. */
c = (c == 9) ? 0 : c + 1; /* Increment c. */
if ((j++ % 80) == 0) { /* Newline after line full. */
usart_send_blocking(USART1, '\r');
usart_send_blocking(USART1, '\n');
usart_send_blocking(USART2, '\r');
usart_send_blocking(USART2, '\n');
usart_send_blocking(USART3, '\r');
usart_send_blocking(USART3, '\n');
}