jackcartersmith/blackmagic
1
0
Fork 0
Code Issues Pull Requests Releases Activity

Add usart example for STM32F4 discovery board

Browse Source
This commit is contained in:
Stephen Caudle 2011-11-02 22:50:49 -04:00
parent 30b5c89726
commit 3c9ba2ac2d
4 changed files with 153 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
examples/stm32/f4/stm32f4-discovery/usart/Makefile Normal file
View File

@ -0,0 +1,23 @@
##
## This file is part of the libopencm3 project.
##
## Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
##
## This program is free software: you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation, either version 3 of the License, or
## (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program. If not, see <http://www.gnu.org/licenses/>.
##
BINARY = usart
include ../../Makefile.include

11
examples/stm32/f4/stm32f4-discovery/usart/README Normal file
View File

@ -0,0 +1,11 @@
------------------------------------------------------------------------------
README
------------------------------------------------------------------------------
This example program sends some characters on USART2 on the
ST STM32F4DISCOVERY eval board.
The terminal settings for the receiving device/PC are 38400 8n1.
The sending is done in a blocking way in the code.

87
examples/stm32/f4/stm32f4-discovery/usart/usart.c Normal file
View File

@ -0,0 +1,87 @@
/*
* This file is part of the libopencm3 project.
*
* Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
* Copyright (C) 2011 Stephen Caudle <scaudle@doceme.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <libopencm3/stm32/f4/rcc.h>
#include <libopencm3/stm32/f4/gpio.h>
#include <libopencm3/stm32/usart.h>
void clock_setup(void)
{
/* Enable GPIOD clock for LED & USARTs. */
rcc_peripheral_enable_clock(&RCC_AHB1ENR, RCC_AHB1ENR_IOPDEN);
rcc_peripheral_enable_clock(&RCC_AHB1ENR, RCC_AHB1ENR_IOPAEN);
/* Enable clocks for USART2. */
rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_USART2EN);
}
void usart_setup(void)
{
/* Setup USART2 parameters. */
usart_set_baudrate(USART2, 38400, rcc_ppre1_frequency);
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);
}
void gpio_setup(void)
{
/* Setup GPIO pin GPIO12 on GPIO port D for LED. */
gpio_mode_setup(GPIOD, GPIO_MODE_OUTPUT,
GPIO_PUPD_NONE,
GPIO12);
/* Setup GPIO pins for USART2 transmit. */
gpio_mode_setup(GPIOA, GPIO_MODE_AF,
GPIO_PUPD_NONE,
GPIO2);
/* Setup USART2 TX pin as alternate function. */
gpio_set_af(GPIOA, GPIO_AF7, GPIO2);
}
int main(void)
{
int i, j = 0, c = 0;
clock_setup();
gpio_setup();
usart_setup();
/* Blink the LED (PD12) on the board with every transmitted byte. */
while (1) {
gpio_toggle(GPIOD, GPIO12); /* LED on/off */
usart_send_blocking(USART2, c + '0'); /* USART2: Send byte. */
c = (c == 9) ? 0 : c + 1; /* Increment c. */
if ((j++ % 80) == 0) { /* Newline after line full. */
usart_send_blocking(USART2, '\r');
usart_send_blocking(USART2, '\n');
}
for (i = 0; i < 3000000; i++) /* Wait a bit. */
__asm__("NOP");
}
return 0;
}

32
examples/stm32/f4/stm32f4-discovery/usart/usart.ld Normal file
View File

@ -0,0 +1,32 @@
/*
* This file is part of the libopencm3 project.
*
* Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
* Copyright (C) 2011 Stephen Caudle <scaudle@doceme.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/* Linker script for ST STM32F4DISCOVERY (STM32F407VG, 1024K flash, 128K RAM). */
/* Define memory regions. */
MEMORY
{
rom (rx) : ORIGIN = 0x08000000, LENGTH = 1024K
ram (rwx) : ORIGIN = 0x20000000, LENGTH = 128K
}
/* Include the common ld script. */
INCLUDE libopencm3_stm32f4.ld