/* * 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 static void clock_setup(void) { rcc_clock_setup_in_hse_12mhz_out_72mhz(); /* Enable GPIOA, GPIOB, GPIOC clock. */ rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPAEN | RCC_APB2ENR_IOPBEN | RCC_APB2ENR_IOPCEN); /* Enable clocks for GPIO port B (for GPIO_USART3_TX) and USART3. */ rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_USART2EN); } static void usart_setup(void) { /* Setup GPIO pin GPIO_USART2_TX. */ gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART2_TX); /* Setup UART parameters. */ usart_set_baudrate(USART2, 38400); 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); } static void gpio_setup(void) { /* Set GPIO8 (in GPIO port A) to 'output push-pull'. */ gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO8); } int main(void) { int i, j = 0, c = 0; clock_setup(); gpio_setup(); usart_setup(); /* Blink the LED (PA8) on the board with every transmitted byte. */ while (1) { gpio_toggle(GPIOA, GPIO8); /* 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 < 800000; i++) /* Wait a bit. */ __asm__("nop"); } return 0; }