global.c
Go to the documentation of this file.
/* 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/>.
*
*/
/* standard libraries */
#include <stdint.h> // standard integer types
#include <stdlib.h> // general utilities
#include <string.h> // memory utilities
/* STM32 (including CM3) libraries */
#include <libopencmsis/core_cm3.h> // Cortex M3 utilities
#include <libopencm3/cm3/nvic.h> // interrupt handler
#include <libopencm3/cm3/systick.h> // SysTick library
#include <libopencm3/stm32/rcc.h> // real-time control clock library
#include <libopencm3/stm32/gpio.h> // general purpose input output library
#include <libopencm3/stm32/exti.h> // external interrupt defines
#include "global.h" // common methods
volatile bool button_flag = false;
volatile bool user_input_available = false;
static volatile uint8_t user_input_buffer[64] = {0};
static volatile uint8_t user_input_i = 0;
static volatile uint8_t user_input_used = 0;
static volatile uint32_t sleep_duration = 0;
char* b2s(uint64_t binary, uint8_t rjust)
{
static char string[64+1] = {0}; // the string representation to return
uint8_t bit = LENGTH(string)-1; // the index of the bit to print
string[bit--] = '\0'; // terminate string
while (binary) {
if (binary & 1) {
string[bit--] = '1';
} else {
string[bit--] = '0';
}
binary >>= 1;
}
while (64-bit-1<rjust && bit>0) {
string[bit--] = '0';
}
return string;
}
void led_on(void)
{
#if defined(BUSVOODOO)
gpio_set_mode(GPIO(LED_PORT), GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO(LED_PIN)); // set LED pin push-pull
#endif
#if defined(LED_ON) && LED_ON
gpio_set(GPIO(LED_PORT), GPIO(LED_PIN));
#else
gpio_clear(GPIO(LED_PORT), GPIO(LED_PIN));
#endif
}
void led_off(void)
{
#if defined(BUSVOODOO)
gpio_set_mode(GPIO(LED_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO(LED_PIN)); // set LED pin to floating to disable LEDs
#else
#if defined(LED_ON) && LED_ON
gpio_clear(GPIO(LED_PORT), GPIO(LED_PIN));
#else
gpio_set(GPIO(LED_PORT), GPIO(LED_PIN));
#endif
#endif
}
void led_toggle(void)
{
#if defined(BUSVOODOO)
gpio_set_mode(GPIO(LED_PORT), GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO(LED_PIN)); // set LED pin to push-pull
#endif
gpio_toggle(GPIO(LED_PORT), GPIO(LED_PIN));
}
void sleep_us(uint32_t duration)
{
systick_counter_disable(); // disable SysTick to reconfigure it
if (!systick_set_frequency(1000000,rcc_ahb_frequency)) { // set SysTick frequency to microseconds
while (true); // unhandled error
}
systick_clear(); // reset SysTick
systick_interrupt_enable(); // enable interrupt to count duration
sleep_duration = duration; // save sleep duration for count down
systick_counter_enable(); // start counting
while (sleep_duration>0) { // wait for count down to complete
__WFI(); // go to sleep
}
}
void sleep_ms(uint32_t duration)
{
systick_counter_disable(); // disable SysTick to reconfigure it
if (!systick_set_frequency(1000,rcc_ahb_frequency)) { // set SysTick frequency to milliseconds
while (true); // unhandled error
}
systick_clear(); // reset SysTick
systick_interrupt_enable(); // enable interrupt to count duration
sleep_duration = duration; // save sleep duration for count down
systick_counter_enable(); // start counting
while (sleep_duration>0) { // wait for count down to complete
__WFI(); // go to sleep
}
}
void sys_tick_handler(void)
{
if (sleep_duration>0) {
sleep_duration--; // decrement duration
}
if (0==sleep_duration) { // sleep complete
systick_counter_disable(); // stop systick
systick_interrupt_disable(); // stop interrupting
sleep_duration = 0; // ensure it still is at 0
}
}
char user_input_get(void)
{
while (!user_input_available) { // wait for user input
__WFI(); // go to sleep
}
volatile char to_return = user_input_buffer[user_input_i]; // get the next available character
user_input_i = (user_input_i+1)%LENGTH(user_input_buffer); // update used buffer
user_input_used--; // update used buffer
user_input_available = (user_input_used!=0); // update available data
return to_return;
}
void user_input_store(char c)
{
// only save data if there is space in the buffer
if (user_input_used>=LENGTH(user_input_buffer)) { // if buffer is full
user_input_i = (user_input_i+1)%LENGTH(user_input_buffer); // drop oldest data
user_input_used--; // update used buffer information
}
user_input_buffer[(user_input_i+user_input_used)%LENGTH(user_input_buffer)] = c; // put character in buffer
user_input_used++; // update used buffer
user_input_available = true; // update available data
}
void board_setup(void)
{
// setup LED
rcc_periph_clock_enable(RCC_GPIO(LED_PORT)); // enable clock for LED
#if defined(BUSVOODOO)
gpio_set_mode(GPIO(LED_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO(LED_PIN)); // set LED pin to floating to disable LEDs
#else
gpio_set_mode(GPIO(LED_PORT), GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO(LED_PIN)); // set LED pin to output push-pull do drive LED
#endif
led_off(); // switch off LED per default
// setup button
#if defined(BUTTON_PORT) && defined(BUTTON_PIN)
rcc_periph_clock_enable(RCC_GPIO(BUTTON_PORT)); // enable clock for button
gpio_set_mode(GPIO(BUTTON_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_PULL_UPDOWN, GPIO(BUTTON_PIN)); // set button pin to input
rcc_periph_clock_enable(RCC_AFIO); // enable alternate function clock for external interrupt
exti_select_source(EXTI(BUTTON_PIN), GPIO(BUTTON_PORT)); // mask external interrupt of this pin only for this port
#if defined(BUTTON_PRESSED) && BUTTON_PRESSED
gpio_clear(GPIO(BUTTON_PORT), GPIO(BUTTON_PIN)); // pull down to be able to detect button push (go high)
exti_set_trigger(EXTI(BUTTON_PIN), EXTI_TRIGGER_RISING); // trigger when button is pressed
#else
gpio_set(GPIO(BUTTON_PORT), GPIO(BUTTON_PIN)); // pull up to be able to detect button push (go low)
exti_set_trigger(EXTI(BUTTON_PIN), EXTI_TRIGGER_FALLING); // trigger when button is pressed
#endif
exti_enable_request(EXTI(BUTTON_PIN)); // enable external interrupt
nvic_enable_irq(NVIC_EXTI_IRQ(BUTTON_PIN)); // enable interrupt
#endif
// reset user input buffer
user_input_available = false;
user_input_i = 0;
user_input_used = 0;
}
#if defined(BUTTON_PIN)
void EXTI_ISR(BUTTON_PIN)(void)
{
exti_reset_request(EXTI(BUTTON_PIN)); // reset interrupt
button_flag = true; // perform button action
}
#endif
board_setup
void board_setup(void)
setup board peripherals
Definition: global.c:169
RCC_GPIO
#define RCC_GPIO(x)
get RCC for GPIO based on GPIO identifier
Definition: global.h:105
led_off
void led_off(void)
switch off board LED
Definition: global.c:80
user_input_store
void user_input_store(char c)
store user input
Definition: global.c:157
NVIC_EXTI_IRQ
#define NVIC_EXTI_IRQ(x)
get NVIC IRQ for external interrupt base on external interrupt/pin
Definition: global.h:156
global.h
global definitions and methods (API)
GPIO
#define GPIO(x)
get GPIO based on GPIO identifier
Definition: global.h:103
user_input_buffer
static volatile uint8_t user_input_buffer[64]
ring buffer for received data
Definition: global.c:38
sleep_us
void sleep_us(uint32_t duration)
go to sleep for some microseconds
Definition: global.c:102
sys_tick_handler
void sys_tick_handler(void)
SysTick interrupt handler.
Definition: global.c:133
b2s
char * b2s(uint64_t binary, uint8_t rjust)
get binary representation of a number
Definition: global.c:44
EXTI
#define EXTI(x)
get external interrupt based on pin identifier
Definition: global.h:154
button_flag
volatile bool button_flag
flag set when board user button has been pressed/released
Definition: global.c:35
user_input_get
char user_input_get(void)
get user input
Definition: global.c:145
EXTI_ISR
#define EXTI_ISR(x)
get interrupt service routine for timer base on external interrupt/pin
Definition: global.h:169
user_input_i
static volatile uint8_t user_input_i
current position of read received data
Definition: global.c:39
sleep_ms
void sleep_ms(uint32_t duration)
go to sleep for some milliseconds
Definition: global.c:117
LENGTH
#define LENGTH(x)
get the length of an array
Definition: global.h:26
led_toggle
void led_toggle(void)
toggle board LED
Definition: global.c:94
sleep_duration
static volatile uint32_t sleep_duration
sleep duration count down (in SysTick interrupts)
Definition: global.c:42
user_input_available
volatile bool user_input_available
flag set when user input is available
Definition: global.c:36
led_on
void led_on(void)
switch on board LED
Definition: global.c:67
user_input_used
static volatile uint8_t user_input_used
how much data has been received and not red
Definition: global.c:40