From 51a3044232207cb2fdb767cd247f445046307b14 Mon Sep 17 00:00:00 2001 From: Piotr Esden-Tempski Date: Thu, 13 Jan 2011 15:10:38 -0800 Subject: [PATCH] Added a simple exti test using rising and falling trigger instead of sampling the gpio pin to determine the current state of the pin. --- .../stm32-h103/exti_rising_falling/Makefile | 23 +++++ .../exti_rising_falling/exti_rising_falling.c | 99 +++++++++++++++++++ .../exti_rising_falling.ld | 31 ++++++ 3 files changed, 153 insertions(+) create mode 100644 examples/stm32/stm32-h103/exti_rising_falling/Makefile create mode 100644 examples/stm32/stm32-h103/exti_rising_falling/exti_rising_falling.c create mode 100644 examples/stm32/stm32-h103/exti_rising_falling/exti_rising_falling.ld diff --git a/examples/stm32/stm32-h103/exti_rising_falling/Makefile b/examples/stm32/stm32-h103/exti_rising_falling/Makefile new file mode 100644 index 00000000..fc603a6c --- /dev/null +++ b/examples/stm32/stm32-h103/exti_rising_falling/Makefile @@ -0,0 +1,23 @@ +## +## This file is part of the libopencm3 project. +## +## Copyright (C) 2009 Uwe Hermann +## +## 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 . +## + +BINARY = exti_rising_falling + +include ../../Makefile.include + diff --git a/examples/stm32/stm32-h103/exti_rising_falling/exti_rising_falling.c b/examples/stm32/stm32-h103/exti_rising_falling/exti_rising_falling.c new file mode 100644 index 00000000..f50047bc --- /dev/null +++ b/examples/stm32/stm32-h103/exti_rising_falling/exti_rising_falling.c @@ -0,0 +1,99 @@ +/* + * This file is part of the libopencm3 project. + * + * Copyright (C) 2009 Uwe Hermann , + * 2010 Piotr Esden-Tempski + * + * 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 . + */ + +#include +#include +#include +#include + +#define FALLING 0 +#define RISING 1 + +u16 exti_direction = FALLING; + +/* Set STM32 to 72 MHz. */ +void clock_setup(void) +{ + rcc_clock_setup_in_hse_8mhz_out_72mhz(); + +} + +void gpio_setup(void) +{ + /* Enable GPIOC clock. */ + rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPCEN); + + /* Set GPIO12 (in GPIO port C) to 'output push-pull'. */ + gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ, + GPIO_CNF_OUTPUT_PUSHPULL, GPIO12); +} + +void exti_setup(void) +{ + /* Enable GPIOA clock. */ + rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPAEN); + + /* Enable AFIO clock. */ + rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_AFIOEN); + + /* Enable EXTI0 interrupt */ + nvic_enable_irq(NVIC_EXTI0_IRQ); + + /* Set GPIO0 (in GPIO port A) to 'input open-drain'. */ + gpio_set_mode(GPIOA, GPIO_MODE_INPUT, + GPIO_CNF_INPUT_PULL_UPDOWN, GPIO0); + gpio_set(GPIOA, GPIO0); + + /* configure EXTI subsystem */ + exti_select_source(EXTI0, GPIOA); + exti_direction = FALLING; + exti_set_trigger(EXTI0, EXTI_TRIGGER_FALLING); + exti_enable_request(EXTI0); +} + +void exti0_isr() +{ + exti_reset_request(EXTI0); + + if (exti_direction == FALLING) { + gpio_set(GPIOC, GPIO12); + exti_direction = RISING; + exti_set_trigger(EXTI0, EXTI_TRIGGER_RISING); + } else { + gpio_clear(GPIOC, GPIO12); + exti_direction = FALLING; + exti_set_trigger(EXTI0, EXTI_TRIGGER_FALLING); + } +} + +int main(void) +{ + + clock_setup(); + gpio_setup(); + exti_setup(); + + /* Blink the LED (PC12) on the board. */ + while (1) { + __asm("nop"); + } + + return 0; +} diff --git a/examples/stm32/stm32-h103/exti_rising_falling/exti_rising_falling.ld b/examples/stm32/stm32-h103/exti_rising_falling/exti_rising_falling.ld new file mode 100644 index 00000000..7ea2b92c --- /dev/null +++ b/examples/stm32/stm32-h103/exti_rising_falling/exti_rising_falling.ld @@ -0,0 +1,31 @@ +/* + * This file is part of the libopencm3 project. + * + * Copyright (C) 2009 Uwe Hermann + * + * 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 . + */ + +/* Linker script for Olimex STM32-H103 (STM32F103RBT6, 128K flash, 20K RAM). */ + +/* Define memory regions. */ +MEMORY +{ + rom (rx) : ORIGIN = 0x08000000, LENGTH = 128K + ram (rwx) : ORIGIN = 0x20000000, LENGTH = 20K +} + +/* Include the common ld script. */ +INCLUDE libopencm3_stm32.ld +