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authorWeston Schmidt2013-02-26 02:41:25 -0800
committerPiotr Esden-Tempski2013-02-26 19:50:13 -0800
commit6ce2c6e13d5d860edc1bafc2606b2b9aa45b444f (patch)
tree10eeefad4d6eb9d45eda99ce27cc51da8f287806 /examples/stm32/f1/stm32-maple/usart_irq
parentb3d895bc6489e7b20af49d8f639436b4d3b679ce (diff)
Add a few example programs for the Leaf Maple / IteadMaple boards.
Diffstat (limited to 'examples/stm32/f1/stm32-maple/usart_irq')
-rw-r--r--examples/stm32/f1/stm32-maple/usart_irq/Makefile25
-rw-r--r--examples/stm32/f1/stm32-maple/usart_irq/usart_irq.c120
2 files changed, 145 insertions, 0 deletions
diff --git a/examples/stm32/f1/stm32-maple/usart_irq/Makefile b/examples/stm32/f1/stm32-maple/usart_irq/Makefile
new file mode 100644
index 0000000..c2eed17
--- /dev/null
+++ b/examples/stm32/f1/stm32-maple/usart_irq/Makefile
@@ -0,0 +1,25 @@
+##
+## This file is part of the libopencm3 project.
+##
+## Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
+##
+## This library is free software: you can redistribute it and/or modify
+## it under the terms of the GNU Lesser General Public License as published by
+## the Free Software Foundation, either version 3 of the License, or
+## (at your option) any later version.
+##
+## This library 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 Lesser General Public License for more details.
+##
+## You should have received a copy of the GNU Lesser General Public License
+## along with this library. If not, see <http://www.gnu.org/licenses/>.
+##
+
+BINARY = usart_irq
+
+LDSCRIPT = ../stm32-maple.ld
+
+include ../../Makefile.include
+
diff --git a/examples/stm32/f1/stm32-maple/usart_irq/usart_irq.c b/examples/stm32/f1/stm32-maple/usart_irq/usart_irq.c
new file mode 100644
index 0000000..bbb2515
--- /dev/null
+++ b/examples/stm32/f1/stm32-maple/usart_irq/usart_irq.c
@@ -0,0 +1,120 @@
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
+ *
+ * This library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This library 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <libopencm3/stm32/f1/rcc.h>
+#include <libopencm3/stm32/f1/gpio.h>
+#include <libopencm3/stm32/usart.h>
+#include <libopencm3/cm3/nvic.h>
+#include <libopencm3/cm3/scb.h>
+
+void clock_setup(void)
+{
+ rcc_clock_setup_in_hse_8mhz_out_72mhz();
+
+ /* Enable GPIOA clock. */
+ rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPAEN);
+
+ /* Enable clocks for GPIO port A (for LED GPIO_USART2_TX) and USART2. */
+ rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_USART2EN);
+}
+
+void usart_setup(void)
+{
+ /* Enable the USART2 interrupt. */
+ nvic_enable_irq(NVIC_USART2_IRQ);
+
+ /* Setup GPIO pin GPIO_USART2_RE_TX on GPIO port A for transmit. */
+ gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ,
+ GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART2_TX);
+
+ /* Setup GPIO pin GPIO_USART2_RE_RX on GPIO port A for receive. */
+ gpio_set_mode(GPIOA, GPIO_MODE_INPUT,
+ GPIO_CNF_INPUT_FLOAT, GPIO_USART2_RX);
+
+ /* Setup UART parameters. */
+ usart_set_baudrate(USART2, 38400);
+ usart_set_databits(USART2, 8);
+ usart_set_stopbits(USART2, USART_STOPBITS_1);
+ usart_set_parity(USART2, USART_PARITY_NONE);
+ usart_set_flow_control(USART2, USART_FLOWCONTROL_NONE);
+ usart_set_mode(USART2, USART_MODE_TX_RX);
+
+ /* Enable USART2 Receive interrupt. */
+ USART_CR1(USART2) |= USART_CR1_RXNEIE;
+
+ /* Finally enable the USART. */
+ usart_enable(USART2);
+}
+
+void gpio_setup(void)
+{
+ gpio_set(GPIOA, GPIO5);
+
+ /* Setup GPIO5 (in GPIO port A) for LED use. */
+ gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ,
+ GPIO_CNF_OUTPUT_PUSHPULL, GPIO5);
+}
+
+void usart2_isr(void)
+{
+ static u8 data = 'A';
+
+ /* Check if we were called because of RXNE. */
+ if (((USART_CR1(USART2) & USART_CR1_RXNEIE) != 0) &&
+ ((USART_SR(USART2) & USART_SR_RXNE) != 0)) {
+
+ /* Indicate that we got data. */
+ gpio_toggle(GPIOA, GPIO5);
+
+ /* Retrieve the data from the peripheral. */
+ data = usart_recv(USART2);
+
+ /* Enable transmit interrupt so it sends back the data. */
+ USART_CR1(USART2) |= USART_CR1_TXEIE;
+ }
+
+ /* Check if we were called because of TXE. */
+ if (((USART_CR1(USART2) & USART_CR1_TXEIE) != 0) &&
+ ((USART_SR(USART2) & USART_SR_TXE) != 0)) {
+
+ /* Indicate that we are sending out data. */
+ // gpio_toggle(GPIOA, GPIO5);
+
+ /* Put data into the transmit register. */
+ usart_send(USART2, data);
+
+ /* Disable the TXE interrupt as we don't need it anymore. */
+ USART_CR1(USART2) &= ~USART_CR1_TXEIE;
+ }
+}
+
+int main(void)
+{
+ SCB_VTOR = (u32) 0x08005000;
+
+ clock_setup();
+ gpio_setup();
+ usart_setup();
+
+ /* Wait forever and do nothing. */
+ while (1)
+ __asm__("nop");
+
+ return 0;
+}