From 22706613d900d8cc309834c1f2fa8b345b8b4494 Mon Sep 17 00:00:00 2001 From: Piotr Esden-Tempski Date: Sun, 11 Mar 2012 23:26:28 -0700 Subject: [PATCH] Added usart irq example for lisa/m 2.0 --- examples/stm32/f1/lisa-m-2/usart_irq/Makefile | 25 ++++ .../stm32/f1/lisa-m-2/usart_irq/usart_irq.c | 126 ++++++++++++++++++ 2 files changed, 151 insertions(+) create mode 100644 examples/stm32/f1/lisa-m-2/usart_irq/Makefile create mode 100644 examples/stm32/f1/lisa-m-2/usart_irq/usart_irq.c diff --git a/examples/stm32/f1/lisa-m-2/usart_irq/Makefile b/examples/stm32/f1/lisa-m-2/usart_irq/Makefile new file mode 100644 index 00000000..7baa2fed --- /dev/null +++ b/examples/stm32/f1/lisa-m-2/usart_irq/Makefile @@ -0,0 +1,25 @@ +## +## This file is part of the libopencm3 project. +## +## Copyright (C) 2009 Uwe Hermann +## +## 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 . +## + +BINARY = usart_irq + +LDSCRIPT = ../lisa-m.ld + +include ../../Makefile.include + diff --git a/examples/stm32/f1/lisa-m-2/usart_irq/usart_irq.c b/examples/stm32/f1/lisa-m-2/usart_irq/usart_irq.c new file mode 100644 index 00000000..dbe9140a --- /dev/null +++ b/examples/stm32/f1/lisa-m-2/usart_irq/usart_irq.c @@ -0,0 +1,126 @@ +/* + * This file is part of the libopencm3 project. + * + * Copyright (C) 2009 Uwe Hermann + * + * 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 . + */ + +#include +#include +#include +#include + +void clock_setup(void) +{ + rcc_clock_setup_in_hse_12mhz_out_72mhz(); + + /* Enable GPIOA clock (for LED GPIOs). */ + rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPAEN | RCC_APB2ENR_IOPCEN); + + /* Enable clocks for GPIO port A (for GPIO_USART2_TX) and USART2. */ + rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPAEN | + RCC_APB2ENR_AFIOEN); + + 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_TX on GPIO port A for transmit. */ + gpio_set_mode(GPIO_BANK_USART2_TX, GPIO_MODE_OUTPUT_50_MHZ, + GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART2_TX); + + /* Setup GPIO pin GPIO_USART2_RX on GPIO port A for receive. */ + gpio_set_mode(GPIO_BANK_USART2_RX, GPIO_MODE_INPUT, + GPIO_CNF_INPUT_FLOAT, GPIO_USART2_RX); + + /* Setup UART parameters. */ + usart_set_baudrate(USART2, 230400); + 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, GPIO8); + + /* Setup GPIO8 (in GPIO port A) for LED use. */ + gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, + GPIO_CNF_OUTPUT_PUSHPULL, GPIO8); + + gpio_set(GPIOC, GPIO15); + + /* Setup GPIO15 (in GPIO port C) for LED use. */ + gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ, + GPIO_CNF_OUTPUT_PUSHPULL, GPIO15); +} + +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, GPIO8); + + /* 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(GPIOC, GPIO15); + + /* 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) +{ + clock_setup(); + gpio_setup(); + usart_setup(); + + /* Wait forever and do nothing. */ + while (1) + __asm__("nop"); + + return 0; +}