mbed library sources. Supersedes mbed-src.
Dependents: LPCXpresso1769_blinky
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DigitalIn.h
00001 /* mbed Microcontroller Library 00002 * Copyright (c) 2006-2013 ARM Limited 00003 * 00004 * Licensed under the Apache License, Version 2.0 (the "License"); 00005 * you may not use this file except in compliance with the License. 00006 * You may obtain a copy of the License at 00007 * 00008 * http://www.apache.org/licenses/LICENSE-2.0 00009 * 00010 * Unless required by applicable law or agreed to in writing, software 00011 * distributed under the License is distributed on an "AS IS" BASIS, 00012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 00013 * See the License for the specific language governing permissions and 00014 * limitations under the License. 00015 */ 00016 #ifndef MBED_DIGITALIN_H 00017 #define MBED_DIGITALIN_H 00018 00019 #include "platform.h" 00020 00021 #include "gpio_api.h" 00022 #include "critical.h" 00023 00024 namespace mbed { 00025 00026 /** A digital input, used for reading the state of a pin 00027 * 00028 * @Note Synchronization level: Interrupt safe 00029 * 00030 * Example: 00031 * @code 00032 * // Flash an LED while a DigitalIn is true 00033 * 00034 * #include "mbed.h" 00035 * 00036 * DigitalIn enable(p5); 00037 * DigitalOut led(LED1); 00038 * 00039 * int main() { 00040 * while(1) { 00041 * if(enable) { 00042 * led = !led; 00043 * } 00044 * wait(0.25); 00045 * } 00046 * } 00047 * @endcode 00048 */ 00049 class DigitalIn { 00050 00051 public: 00052 /** Create a DigitalIn connected to the specified pin 00053 * 00054 * @param pin DigitalIn pin to connect to 00055 */ 00056 DigitalIn(PinName pin) : gpio() { 00057 // No lock needed in the constructor 00058 gpio_init_in(&gpio, pin); 00059 } 00060 00061 /** Create a DigitalIn connected to the specified pin 00062 * 00063 * @param pin DigitalIn pin to connect to 00064 * @param mode the initial mode of the pin 00065 */ 00066 DigitalIn(PinName pin, PinMode mode) : gpio() { 00067 // No lock needed in the constructor 00068 gpio_init_in_ex(&gpio, pin, mode); 00069 } 00070 /** Read the input, represented as 0 or 1 (int) 00071 * 00072 * @returns 00073 * An integer representing the state of the input pin, 00074 * 0 for logical 0, 1 for logical 1 00075 */ 00076 int read() { 00077 // Thread safe / atomic HAL call 00078 return gpio_read(&gpio); 00079 } 00080 00081 /** Set the input pin mode 00082 * 00083 * @param mode PullUp, PullDown, PullNone, OpenDrain 00084 */ 00085 void mode(PinMode pull) { 00086 core_util_critical_section_enter(); 00087 gpio_mode(&gpio, pull); 00088 core_util_critical_section_exit(); 00089 } 00090 00091 /** Return the output setting, represented as 0 or 1 (int) 00092 * 00093 * @returns 00094 * Non zero value if pin is connected to uc GPIO 00095 * 0 if gpio object was initialized with NC 00096 */ 00097 int is_connected() { 00098 // Thread safe / atomic HAL call 00099 return gpio_is_connected(&gpio); 00100 } 00101 00102 /** An operator shorthand for read() 00103 */ 00104 operator int() { 00105 // Underlying read is thread safe 00106 return read(); 00107 } 00108 00109 protected: 00110 gpio_t gpio; 00111 }; 00112 00113 } // namespace mbed 00114 00115 #endif
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