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/* mbed Microcontroller Library
* Copyright (c) 2006-2013 ARM Limited
*
* 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.
*/
#ifndef MBED_DIGITALOUT_H
#define MBED_DIGITALOUT_H
#include "platform/platform.h"
#include "hal/gpio_api.h"
#include "platform/mbed_critical.h"
namespace mbed {
/** \addtogroup drivers */
/** @{*/
/** A digital output, used for setting the state of a pin
*
* @Note Synchronization level: Interrupt safe
*
* Example:
* @code
* // Toggle a LED
* #include "mbed.h"
*
* DigitalOut led(LED1);
*
* int main() {
* while(1) {
* led = !led;
* wait(0.2);
* }
* }
* @endcode
*/
class DigitalOut {
public:
/** Create a DigitalOut connected to the specified pin
*
* @param pin DigitalOut pin to connect to
*/
DigitalOut(PinName pin) : gpio() {
// No lock needed in the constructor
gpio_init_out(&gpio, pin);
}
/** Create a DigitalOut connected to the specified pin
*
* @param pin DigitalOut pin to connect to
* @param value the initial pin value
*/
DigitalOut(PinName pin, int value) : gpio() {
// No lock needed in the constructor
gpio_init_out_ex(&gpio, pin, value);
}
/** Set the output, specified as 0 or 1 (int)
*
* @param value An integer specifying the pin output value,
* 0 for logical 0, 1 (or any other non-zero value) for logical 1
*/
void write(int value) {
// Thread safe / atomic HAL call
gpio_write(&gpio, value);
}
/** Return the output setting, represented as 0 or 1 (int)
*
* @returns
* an integer representing the output setting of the pin,
* 0 for logical 0, 1 for logical 1
*/
int read() {
// Thread safe / atomic HAL call
return gpio_read(&gpio);
}
/** Return the output setting, represented as 0 or 1 (int)
*
* @returns
* Non zero value if pin is connected to uc GPIO
* 0 if gpio object was initialized with NC
*/
int is_connected() {
// Thread safe / atomic HAL call
return gpio_is_connected(&gpio);
}
/** A shorthand for write()
*/
DigitalOut& operator= (int value) {
// Underlying write is thread safe
write(value);
return *this;
}
DigitalOut& operator= (DigitalOut& rhs) {
core_util_critical_section_enter();
write(rhs.read());
core_util_critical_section_exit();
return *this;
}
/** A shorthand for read()
*/
operator int() {
// Underlying call is thread safe
return read();
}
protected:
gpio_t gpio;
};
} // namespace mbed
#endif
/** @}*/
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