165 lines
4.6 KiB
C
165 lines
4.6 KiB
C
/*
|
|
* This file is part of the libopencm3 project.
|
|
*
|
|
* Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
|
|
* Copyright (C) 2013 Stephen Dwyer <scdwyer@ualberta.ca>
|
|
*
|
|
* 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/rcc.h>
|
|
#include <libopencm3/stm32/gpio.h>
|
|
#include <libopencm3/stm32/usart.h>
|
|
#include <libopencm3/stm32/dma.h>
|
|
#include <libopencm3/cm3/nvic.h>
|
|
#include <libopencm3/stm32/spi.h>
|
|
#include <stdio.h>
|
|
#include <errno.h>
|
|
|
|
int _write(int file, char *ptr, int len);
|
|
|
|
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 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);
|
|
|
|
/* Enable SPI1 Periph and gpio clocks */
|
|
rcc_peripheral_enable_clock(&RCC_APB2ENR,
|
|
RCC_APB2ENR_SPI1EN);
|
|
|
|
}
|
|
|
|
static void spi_setup(void) {
|
|
|
|
/* Configure GPIOs: SS=PA4, SCK=PA5, MISO=PA6 and MOSI=PA7 */
|
|
gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ,
|
|
GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO4 |
|
|
GPIO5 |
|
|
GPIO7 );
|
|
|
|
gpio_set_mode(GPIOA, GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT,
|
|
GPIO6);
|
|
|
|
/* Reset SPI, SPI_CR1 register cleared, SPI is disabled */
|
|
spi_reset(SPI1);
|
|
|
|
/* Set up SPI in Master mode with:
|
|
* Clock baud rate: 1/64 of peripheral clock frequency
|
|
* Clock polarity: Idle High
|
|
* Clock phase: Data valid on 2nd clock pulse
|
|
* Data frame format: 8-bit
|
|
* Frame format: MSB First
|
|
*/
|
|
spi_init_master(SPI1, SPI_CR1_BAUDRATE_FPCLK_DIV_64, SPI_CR1_CPOL_CLK_TO_1_WHEN_IDLE,
|
|
SPI_CR1_CPHA_CLK_TRANSITION_2, SPI_CR1_DFF_8BIT, SPI_CR1_MSBFIRST);
|
|
|
|
/*
|
|
* Set NSS management to software.
|
|
*
|
|
* Note:
|
|
* Setting nss high is very important, even if we are controlling the GPIO
|
|
* ourselves this bit needs to be at least set to 1, otherwise the spi
|
|
* peripheral will not send any data out.
|
|
*/
|
|
spi_enable_software_slave_management(SPI1);
|
|
spi_set_nss_high(SPI1);
|
|
|
|
/* Enable SPI1 periph. */
|
|
spi_enable(SPI1);
|
|
}
|
|
|
|
static void usart_setup(void)
|
|
{
|
|
/* Setup GPIO pin GPIO_USART2_TX and GPIO_USART2_RX. */
|
|
gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ,
|
|
GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART2_TX);
|
|
gpio_set_mode(GPIOA, GPIO_MODE_INPUT,
|
|
GPIO_CNF_INPUT_FLOAT, GPIO_USART2_RX);
|
|
|
|
/* Setup UART parameters. */
|
|
usart_set_baudrate(USART2, 9600);
|
|
usart_set_databits(USART2, 8);
|
|
usart_set_stopbits(USART2, USART_STOPBITS_1);
|
|
usart_set_mode(USART2, USART_MODE_TX_RX);
|
|
usart_set_parity(USART2, USART_PARITY_NONE);
|
|
usart_set_flow_control(USART2, USART_FLOWCONTROL_NONE);
|
|
|
|
/* Finally enable the USART. */
|
|
usart_enable(USART2);
|
|
}
|
|
|
|
int _write(int file, char *ptr, int len)
|
|
{
|
|
int i;
|
|
|
|
if (file == 1) {
|
|
for (i = 0; i < len; i++)
|
|
usart_send_blocking(USART2, ptr[i]);
|
|
return i;
|
|
}
|
|
|
|
errno = EIO;
|
|
return -1;
|
|
}
|
|
|
|
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 counter = 0;
|
|
u16 rx_value = 0x42;
|
|
|
|
clock_setup();
|
|
gpio_setup();
|
|
usart_setup();
|
|
spi_setup();
|
|
|
|
|
|
/* Blink the LED (PA8) on the board with every transmitted byte. */
|
|
while (1) {
|
|
/* LED on/off */
|
|
gpio_toggle(GPIOA, GPIO8);
|
|
|
|
/* printf the value that SPI should send */
|
|
printf("Counter: %i SPI Sent Byte: %i", counter, (uint8_t) counter);
|
|
/* blocking send of the byte out SPI1 */
|
|
spi_send(SPI1, (uint8_t) counter);
|
|
/* Read the byte that just came in (use a loopback between MISO and MOSI
|
|
* to get the same byte back)
|
|
*/
|
|
rx_value = spi_read(SPI1);
|
|
/* printf the byte just received */
|
|
printf(" SPI Received Byte: %i\r\n", rx_value);
|
|
|
|
counter++;
|
|
|
|
}
|
|
|
|
return 0;
|
|
}
|