forked
Embed:
(wiki syntax)
Show/hide line numbers
AnalogOut.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_ANALOGOUT_H 00017 #define MBED_ANALOGOUT_H 00018 00019 #include "platform/platform.h" 00020 00021 #if defined (DEVICE_ANALOGOUT) || defined(DOXYGEN_ONLY) 00022 00023 #include "hal/analogout_api.h" 00024 #include "platform/PlatformMutex.h" 00025 00026 namespace mbed { 00027 /** \addtogroup drivers */ 00028 00029 /** An analog output, used for setting the voltage on a pin 00030 * 00031 * @note Synchronization level: Thread safe 00032 * 00033 * Example: 00034 * @code 00035 * // Make a sawtooth output 00036 * 00037 * #include "mbed.h" 00038 * 00039 * AnalogOut tri(p18); 00040 * int main() { 00041 * while(1) { 00042 * tri = tri + 0.01; 00043 * wait_us(1); 00044 * if(tri == 1) { 00045 * tri = 0; 00046 * } 00047 * } 00048 * } 00049 * @endcode 00050 * @ingroup drivers 00051 */ 00052 class AnalogOut { 00053 00054 public: 00055 00056 /** Create an AnalogOut connected to the specified pin 00057 * 00058 * @param pin AnalogOut pin to connect to 00059 */ 00060 AnalogOut(PinName pin) { 00061 analogout_init(&_dac, pin); 00062 } 00063 00064 /** Set the output voltage, specified as a percentage (float) 00065 * 00066 * @param value A floating-point value representing the output voltage, 00067 * specified as a percentage. The value should lie between 00068 * 0.0f (representing 0v / 0%) and 1.0f (representing 3.3v / 100%). 00069 * Values outside this range will be saturated to 0.0f or 1.0f. 00070 */ 00071 void write(float value) { 00072 lock(); 00073 analogout_write(&_dac, value); 00074 unlock(); 00075 } 00076 00077 /** Set the output voltage, represented as an unsigned short in the range [0x0, 0xFFFF] 00078 * 00079 * @param value 16-bit unsigned short representing the output voltage, 00080 * normalised to a 16-bit value (0x0000 = 0v, 0xFFFF = 3.3v) 00081 */ 00082 void write_u16(unsigned short value) { 00083 lock(); 00084 analogout_write_u16(&_dac, value); 00085 unlock(); 00086 } 00087 00088 /** Return the current output voltage setting, measured as a percentage (float) 00089 * 00090 * @returns 00091 * A floating-point value representing the current voltage being output on the pin, 00092 * measured as a percentage. The returned value will lie between 00093 * 0.0f (representing 0v / 0%) and 1.0f (representing 3.3v / 100%). 00094 * 00095 * @note 00096 * This value may not match exactly the value set by a previous write(). 00097 */ 00098 float read() { 00099 lock(); 00100 float ret = analogout_read(&_dac); 00101 unlock(); 00102 return ret; 00103 } 00104 00105 /** An operator shorthand for write() 00106 * \sa AnalogOut::write() 00107 */ 00108 AnalogOut& operator= (float percent) { 00109 // Underlying write call is thread safe 00110 write(percent); 00111 return *this; 00112 } 00113 00114 /** An operator shorthand for write() 00115 * \sa AnalogOut::write() 00116 */ 00117 AnalogOut& operator= (AnalogOut& rhs) { 00118 // Underlying write call is thread safe 00119 write(rhs.read()); 00120 return *this; 00121 } 00122 00123 /** An operator shorthand for read() 00124 * \sa AnalogOut::read() 00125 */ 00126 operator float() { 00127 // Underlying read call is thread safe 00128 return read(); 00129 } 00130 00131 virtual ~AnalogOut() { 00132 // Do nothing 00133 } 00134 00135 protected: 00136 00137 virtual void lock() { 00138 _mutex.lock(); 00139 } 00140 00141 virtual void unlock() { 00142 _mutex.unlock(); 00143 } 00144 00145 dac_t _dac; 00146 PlatformMutex _mutex; 00147 }; 00148 00149 } // namespace mbed 00150 00151 #endif 00152 00153 #endif
Generated on Tue Jul 12 2022 16:02:31 by 1.7.2