firefly_conductor/main.c

/* 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 <http://www.gnu.org/licenses/>.
 *
 */
/* Copyright (c) 2016 King Kévin <kingkevin@cuvoodoo.info> */

/* standard libraries */
#include <stdint.h> // standard integer types
#include <stdio.h> // standard I/O facilities
#include <stdlib.h> // standard utilities
#include <unistd.h> // standard streams
#include <errno.h> // error number utilities

/* STM32 (including CM3) libraries */
#include <libopencm3/stm32/rcc.h> // real-time control clock library
#include <libopencm3/stm32/gpio.h> // general purpose input output library
#include <libopencm3/cm3/scb.h> // vector table definition
#include <libopencmsis/core_cm3.h> // Cortex M3 utilities

#include <libopencm3/stm32/timer.h>
#include <libopencm3/cm3/nvic.h>

/* own libraries */
#include "global.h" // board definitions
#include "usart.h" // USART utilities
#include "usb_cdcacm.h" // USB CDC ACM utilities
#include "vfd.h" // VFD driver

/* default output (i.e. for printf) */
int _write(int file, char *ptr, int len)
{
	int i;

	if (file == STDOUT_FILENO || file == STDERR_FILENO) {
		for (i = 0; i < len; i++) {
			if (ptr[i] == '\n') { // add carrier return before line feed. this is recommended for most UART terminals
				usart_putchar_nonblocking('\r'); // a second line feed doesn't break the display
				cdcacm_putchar('\r'); // a second line feed doesn't break the display
			}
			usart_putchar_nonblocking(ptr[i]); // send byte over USART
			cdcacm_putchar(ptr[i]); // send byte over USB
		}
		return i;
	}
	errno = EIO;
	return -1;
}

static void gpio_setup(void)
{
	rcc_periph_clock_enable(LED_RCC); //enable clock for LED
	gpio_set_mode(LED_PORT, GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, LED_PIN); // set LED pin to 'output push-pull'	
}

int main(void)
{	
	SCB_VTOR = (uint32_t) 0x08002000; // relocate vector table because of the bootloader
	rcc_clock_setup_in_hse_8mhz_out_72mhz(); // use 8 MHz high speed external clock to generate 72 MHz internal clock

	gpio_setup(); // setup main inputs/outputs
	usart_setup(); // setup USART (for printing)
	cdcacm_setup(); // setup USB CDC ACM (for printing)	
	vfd_setup(); // setup VFD
	
	setbuf(stdout, NULL); // set standard out buffer to NULL to immediately print	
	setbuf(stderr, NULL); // set standard error buffer to NULL to immediately print

	printf("welcome to the STM32F1 CuVoodoo display driver\n");


	vfd_on(); // switch on VFD
	vfd_test(); // show all anodes
	for (uint32_t i = 0; i < 0x800000; i++) { // show for a bit of time
		__asm__("nop");
	}
	vfd_clear(); // clear all data

	uint8_t vfd_place = 0; // the place on which the next character will be displayed on the VFD
	bool vfd_flag = false; // do something with the VFD
	char c = 0; // the character to display
	while (true) {
		while (usart_received) { // echo every received character
			c = usart_getchar();
			vfd_flag = true; // display character
		}
		while (cdcacm_received) { // echo every received character
			c = cdcacm_getchar();
			vfd_flag = true; // display character
		}
		while (vfd_flag) {
			vfd_flag = false;
				printf("%c", c); // transmit receive character
			gpio_toggle(LED_PORT, LED_PIN); // toggle LED to show activity
			if (c=='\r' || c=='\n') { // on newline
				vfd_clear(); // clear display
				vfd_place = 0; // restart from beginning
			} else {
				vfd_digit(vfd_place,c); // display character on digit
				vfd_matrix(vfd_place,c); // display character on matrix
				vfd_place++; // go to next place
			}
		}	
		__WFI(); // go to sleep
	}

	return 0;
}