I am in a situation where I can to respond to a pulse that is very short, around 3 microseconds wide.
An interrupt is necessary and I stumbled across the EXT driver.
In the testhal folder there is a simple example but what I don't understand.
Edit.
What I dont understand, how do you select which pin on GPIOA and GPIOC the EXT driver is reacting on
Regards
Sebastian Aslund
Code: Select all
/*
ChibiOS - Copyright (C) 2006..2015 Giovanni Di Sirio
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
#include "ch.h"
#include "hal.h"
static virtual_timer_t vt;
/* LED set to OFF after 200mS.*/
static void ledoff(void *arg) {
(void)arg;
palSetPad(GPIOC, GPIOC_LED);
}
/* Triggered when the button is pressed or released. The LED is set to ON.*/
static void extcb1(EXTDriver *extp, expchannel_t channel) {
(void)extp;
(void)channel;
palClearPad(GPIOC, GPIOC_LED);
chSysLockFromISR();
chVTSetI(&vt, MS2ST(200), ledoff, NULL);
chSysUnlockFromISR();
}
/* Triggered when the LED goes OFF.*/
static void extcb2(EXTDriver *extp, expchannel_t channel) {
(void)extp;
(void)channel;
}
static const EXTConfig extcfg = {
{
{EXT_CH_MODE_BOTH_EDGES | EXT_CH_MODE_AUTOSTART | EXT_MODE_GPIOA, extcb1},
{EXT_CH_MODE_DISABLED, NULL},
{EXT_CH_MODE_DISABLED, NULL},
{EXT_CH_MODE_DISABLED, NULL},
{EXT_CH_MODE_DISABLED, NULL},
{EXT_CH_MODE_DISABLED, NULL},
{EXT_CH_MODE_DISABLED, NULL},
{EXT_CH_MODE_DISABLED, NULL},
{EXT_CH_MODE_DISABLED, NULL},
{EXT_CH_MODE_DISABLED, NULL},
{EXT_CH_MODE_DISABLED, NULL},
{EXT_CH_MODE_DISABLED, NULL},
{EXT_CH_MODE_RISING_EDGE | EXT_CH_MODE_AUTOSTART | EXT_MODE_GPIOC, extcb2},
{EXT_CH_MODE_DISABLED, NULL},
{EXT_CH_MODE_DISABLED, NULL},
{EXT_CH_MODE_DISABLED, NULL}
}
};
/*
* Application entry point.
*/
int main(void) {
/*
* System initializations.
* - HAL initialization, this also initializes the configured device drivers
* and performs the board-specific initializations.
* - Kernel initialization, the main() function becomes a thread and the
* RTOS is active.
*/
halInit();
chSysInit();
/*
* Activates the EXT driver 1.
*/
extStart(&EXTD1, &extcfg);
/*
* Normal main() thread activity, in this demo it enables and disables the
* button EXT channel using 5 seconds intervals.
*/
while (true) {
chThdSleepMilliseconds(5000);
extChannelDisable(&EXTD1, 0);
chThdSleepMilliseconds(5000);
extChannelEnable(&EXTD1, 0);
}
}
