siva surendar / mbed-dev

mbed library sources. Supersedes mbed-src.

Fork of mbed-dev by mbed official

drivers/AnalogOut.h@150:da61ba4e9755, 2016-11-25 (annotated)

Committer:
sivasuren
Date:
Fri Nov 25 07:57:40 2016 +0000
Revision:
150:da61ba4e9755
Parent:
149:156823d33999 
surendar changes

Who changed what in which revision?

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<> 149:156823d33999 1 /* mbed Microcontroller Library
<> 149:156823d33999 2 * Copyright (c) 2006-2013 ARM Limited
<> 149:156823d33999 3 *
<> 149:156823d33999 4 * Licensed under the Apache License, Version 2.0 (the "License");
<> 149:156823d33999 5 * you may not use this file except in compliance with the License.
<> 149:156823d33999 6 * You may obtain a copy of the License at
<> 149:156823d33999 7 *
<> 149:156823d33999 8 * http://www.apache.org/licenses/LICENSE-2.0
<> 149:156823d33999 9 *
<> 149:156823d33999 10 * Unless required by applicable law or agreed to in writing, software
<> 149:156823d33999 11 * distributed under the License is distributed on an "AS IS" BASIS,
<> 149:156823d33999 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
<> 149:156823d33999 13 * See the License for the specific language governing permissions and
<> 149:156823d33999 14 * limitations under the License.
<> 149:156823d33999 15 */
<> 149:156823d33999 16 #ifndef MBED_ANALOGOUT_H
<> 149:156823d33999 17 #define MBED_ANALOGOUT_H
<> 149:156823d33999 18
<> 149:156823d33999 19 #include "platform/platform.h"
<> 149:156823d33999 20
<> 149:156823d33999 21 #if DEVICE_ANALOGOUT
<> 149:156823d33999 22
<> 149:156823d33999 23 #include "hal/analogout_api.h"
<> 149:156823d33999 24 #include "platform/PlatformMutex.h"
<> 149:156823d33999 25
<> 149:156823d33999 26 namespace mbed {
<> 149:156823d33999 27 /** \addtogroup drivers */
<> 149:156823d33999 28 /** @{*/
<> 149:156823d33999 29
<> 149:156823d33999 30 /** An analog output, used for setting the voltage on a pin
<> 149:156823d33999 31 *
<> 149:156823d33999 32 * @Note Synchronization level: Thread safe
<> 149:156823d33999 33 *
<> 149:156823d33999 34 * Example:
<> 149:156823d33999 35 * @code
<> 149:156823d33999 36 * // Make a sawtooth output
<> 149:156823d33999 37 *
<> 149:156823d33999 38 * #include "mbed.h"
<> 149:156823d33999 39 *
<> 149:156823d33999 40 * AnalogOut tri(p18);
<> 149:156823d33999 41 * int main() {
<> 149:156823d33999 42 * while(1) {
<> 149:156823d33999 43 * tri = tri + 0.01;
<> 149:156823d33999 44 * wait_us(1);
<> 149:156823d33999 45 * if(tri == 1) {
<> 149:156823d33999 46 * tri = 0;
<> 149:156823d33999 47 * }
<> 149:156823d33999 48 * }
<> 149:156823d33999 49 * }
<> 149:156823d33999 50 * @endcode
<> 149:156823d33999 51 */
<> 149:156823d33999 52 class AnalogOut {
<> 149:156823d33999 53
<> 149:156823d33999 54 public:
<> 149:156823d33999 55
<> 149:156823d33999 56 /** Create an AnalogOut connected to the specified pin
<> 149:156823d33999 57 *
<> 149:156823d33999 58 * @param AnalogOut pin to connect to (18)
<> 149:156823d33999 59 */
<> 149:156823d33999 60 AnalogOut(PinName pin) {
<> 149:156823d33999 61 analogout_init(&_dac, pin);
<> 149:156823d33999 62 }
<> 149:156823d33999 63
<> 149:156823d33999 64 /** Set the output voltage, specified as a percentage (float)
<> 149:156823d33999 65 *
<> 149:156823d33999 66 * @param value A floating-point value representing the output voltage,
<> 149:156823d33999 67 * specified as a percentage. The value should lie between
<> 149:156823d33999 68 * 0.0f (representing 0v / 0%) and 1.0f (representing 3.3v / 100%).
<> 149:156823d33999 69 * Values outside this range will be saturated to 0.0f or 1.0f.
<> 149:156823d33999 70 */
<> 149:156823d33999 71 void write(float value) {
<> 149:156823d33999 72 lock();
<> 149:156823d33999 73 analogout_write(&_dac, value);
<> 149:156823d33999 74 unlock();
<> 149:156823d33999 75 }
<> 149:156823d33999 76
<> 149:156823d33999 77 /** Set the output voltage, represented as an unsigned short in the range [0x0, 0xFFFF]
<> 149:156823d33999 78 *
<> 149:156823d33999 79 * @param value 16-bit unsigned short representing the output voltage,
<> 149:156823d33999 80 * normalised to a 16-bit value (0x0000 = 0v, 0xFFFF = 3.3v)
<> 149:156823d33999 81 */
<> 149:156823d33999 82 void write_u16(unsigned short value) {
<> 149:156823d33999 83 lock();
<> 149:156823d33999 84 analogout_write_u16(&_dac, value);
<> 149:156823d33999 85 unlock();
<> 149:156823d33999 86 }
<> 149:156823d33999 87
<> 149:156823d33999 88 /** Return the current output voltage setting, measured as a percentage (float)
<> 149:156823d33999 89 *
<> 149:156823d33999 90 * @returns
<> 149:156823d33999 91 * A floating-point value representing the current voltage being output on the pin,
<> 149:156823d33999 92 * measured as a percentage. The returned value will lie between
<> 149:156823d33999 93 * 0.0f (representing 0v / 0%) and 1.0f (representing 3.3v / 100%).
<> 149:156823d33999 94 *
<> 149:156823d33999 95 * @note
<> 149:156823d33999 96 * This value may not match exactly the value set by a previous write().
<> 149:156823d33999 97 */
<> 149:156823d33999 98 float read() {
<> 149:156823d33999 99 lock();
<> 149:156823d33999 100 float ret = analogout_read(&_dac);
<> 149:156823d33999 101 unlock();
<> 149:156823d33999 102 return ret;
<> 149:156823d33999 103 }
<> 149:156823d33999 104
<> 149:156823d33999 105 /** An operator shorthand for write()
<> 149:156823d33999 106 */
<> 149:156823d33999 107 AnalogOut& operator= (float percent) {
<> 149:156823d33999 108 // Underlying write call is thread safe
<> 149:156823d33999 109 write(percent);
<> 149:156823d33999 110 return *this;
<> 149:156823d33999 111 }
<> 149:156823d33999 112
<> 149:156823d33999 113 AnalogOut& operator= (AnalogOut& rhs) {
<> 149:156823d33999 114 // Underlying write call is thread safe
<> 149:156823d33999 115 write(rhs.read());
<> 149:156823d33999 116 return *this;
<> 149:156823d33999 117 }
<> 149:156823d33999 118
<> 149:156823d33999 119 /** An operator shorthand for read()
<> 149:156823d33999 120 */
<> 149:156823d33999 121 operator float() {
<> 149:156823d33999 122 // Underlying read call is thread safe
<> 149:156823d33999 123 return read();
<> 149:156823d33999 124 }
<> 149:156823d33999 125
<> 149:156823d33999 126 virtual ~AnalogOut() {
<> 149:156823d33999 127 // Do nothing
<> 149:156823d33999 128 }
<> 149:156823d33999 129
<> 149:156823d33999 130 protected:
<> 149:156823d33999 131
<> 149:156823d33999 132 virtual void lock() {
<> 149:156823d33999 133 _mutex.lock();
<> 149:156823d33999 134 }
<> 149:156823d33999 135
<> 149:156823d33999 136 virtual void unlock() {
<> 149:156823d33999 137 _mutex.unlock();
<> 149:156823d33999 138 }
<> 149:156823d33999 139
<> 149:156823d33999 140 dac_t _dac;
<> 149:156823d33999 141 PlatformMutex _mutex;
<> 149:156823d33999 142 };
<> 149:156823d33999 143
<> 149:156823d33999 144 } // namespace mbed
<> 149:156823d33999 145
<> 149:156823d33999 146 #endif
<> 149:156823d33999 147
<> 149:156823d33999 148 #endif
<> 149:156823d33999 149
<> 149:156823d33999 150 /** @}*/