/* * This file is part of the libopencm3 project. * * Copyright (C) 2011 Fergus Noble * Copyright (C) 2011 Henry Hallam * * 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 #include #include #include void clock_setup(void) { /* Enable clocks on all the peripherals we are going to use. */ rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_SPI2EN); rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_USART1EN); rcc_peripheral_enable_clock(&RCC_AHB1ENR, RCC_AHB1ENR_IOPCEN | RCC_AHB1ENR_IOPAEN | RCC_AHB1ENR_IOPBEN); } void spi_setup(void) { gpio_mode_setup(GPIOB, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO13 | GPIO14 | GPIO15); gpio_set_af(GPIOB, GPIO_AF5, GPIO13 | GPIO14 | GPIO15); /* Setup SPI parameters. */ spi_init_master(SPI2, SPI_CR1_BAUDRATE_FPCLK_DIV_256, SPI_CR1_CPOL, SPI_CR1_CPHA, SPI_CR1_DFF_8BIT, SPI_CR1_MSBFIRST); spi_enable_ss_output(SPI2); /* Required, see NSS, 25.3.1 section. */ /* Finally enable the SPI. */ spi_enable(SPI2); } void usart_setup(void) { gpio_mode_setup(GPIOA, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO9); gpio_set_af(GPIOA, GPIO_AF7, GPIO9 | GPIO10); /* Setup UART parameters. */ usart_set_baudrate(USART1, 9600); usart_set_databits(USART1, 8); usart_set_stopbits(USART1, USART_STOPBITS_1); usart_set_parity(USART1, USART_PARITY_NONE); usart_set_flow_control(USART1, USART_FLOWCONTROL_NONE); usart_set_mode(USART1, USART_MODE_TX); /* Finally enable the USART. */ usart_enable(USART1); } void gpio_setup(void) { gpio_set(GPIOC, GPIO3); /* Setup GPIO3 (in GPIO port C) for LED use. */ gpio_mode_setup(GPIOC, GPIO_MODE_OUTPUT, GPIO_MODE_OUTPUT, GPIO3); } int _write(int file, char *ptr, int len) { int i; if (file == 1) { for (i = 0; i < len; i++) usart_send_blocking(USART1, ptr[i]); return i; } errno = EIO; return -1; } int main(void) { int counter = 0; volatile u16 dummy __attribute__((unused)); clock_setup(); gpio_setup(); usart_setup(); spi_setup(); while (1) { counter++; printf("Hello, world! %i\r\n", counter); /* Stops RX buffer overflow, but probably not needed. */ dummy = spi_read(SPI2); spi_send(SPI2, (u8) counter); gpio_toggle(GPIOC, GPIO3); } while (1); return 0; }