Lee Kai Xuan / mbed-os

mbed-os

Fork of mbed-os by erkin yucel

drivers/AnalogOut.h@0:f269e3021894, 2016-10-23 (annotated)

Committer:
elessair
Date:
Sun Oct 23 15:10:02 2016 +0000
Revision:
0:f269e3021894
Initial commit

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elessair 0:f269e3021894 1 /* mbed Microcontroller Library
elessair 0:f269e3021894 2 * Copyright (c) 2006-2013 ARM Limited
elessair 0:f269e3021894 3 *
elessair 0:f269e3021894 4 * Licensed under the Apache License, Version 2.0 (the "License");
elessair 0:f269e3021894 5 * you may not use this file except in compliance with the License.
elessair 0:f269e3021894 6 * You may obtain a copy of the License at
elessair 0:f269e3021894 7 *
elessair 0:f269e3021894 8 * http://www.apache.org/licenses/LICENSE-2.0
elessair 0:f269e3021894 9 *
elessair 0:f269e3021894 10 * Unless required by applicable law or agreed to in writing, software
elessair 0:f269e3021894 11 * distributed under the License is distributed on an "AS IS" BASIS,
elessair 0:f269e3021894 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
elessair 0:f269e3021894 13 * See the License for the specific language governing permissions and
elessair 0:f269e3021894 14 * limitations under the License.
elessair 0:f269e3021894 15 */
elessair 0:f269e3021894 16 #ifndef MBED_ANALOGOUT_H
elessair 0:f269e3021894 17 #define MBED_ANALOGOUT_H
elessair 0:f269e3021894 18
elessair 0:f269e3021894 19 #include "platform/platform.h"
elessair 0:f269e3021894 20
elessair 0:f269e3021894 21 #if DEVICE_ANALOGOUT
elessair 0:f269e3021894 22
elessair 0:f269e3021894 23 #include "hal/analogout_api.h"
elessair 0:f269e3021894 24 #include "platform/PlatformMutex.h"
elessair 0:f269e3021894 25
elessair 0:f269e3021894 26 namespace mbed {
elessair 0:f269e3021894 27 /** \addtogroup drivers */
elessair 0:f269e3021894 28 /** @{*/
elessair 0:f269e3021894 29
elessair 0:f269e3021894 30 /** An analog output, used for setting the voltage on a pin
elessair 0:f269e3021894 31 *
elessair 0:f269e3021894 32 * @Note Synchronization level: Thread safe
elessair 0:f269e3021894 33 *
elessair 0:f269e3021894 34 * Example:
elessair 0:f269e3021894 35 * @code
elessair 0:f269e3021894 36 * // Make a sawtooth output
elessair 0:f269e3021894 37 *
elessair 0:f269e3021894 38 * #include "mbed.h"
elessair 0:f269e3021894 39 *
elessair 0:f269e3021894 40 * AnalogOut tri(p18);
elessair 0:f269e3021894 41 * int main() {
elessair 0:f269e3021894 42 * while(1) {
elessair 0:f269e3021894 43 * tri = tri + 0.01;
elessair 0:f269e3021894 44 * wait_us(1);
elessair 0:f269e3021894 45 * if(tri == 1) {
elessair 0:f269e3021894 46 * tri = 0;
elessair 0:f269e3021894 47 * }
elessair 0:f269e3021894 48 * }
elessair 0:f269e3021894 49 * }
elessair 0:f269e3021894 50 * @endcode
elessair 0:f269e3021894 51 */
elessair 0:f269e3021894 52 class AnalogOut {
elessair 0:f269e3021894 53
elessair 0:f269e3021894 54 public:
elessair 0:f269e3021894 55
elessair 0:f269e3021894 56 /** Create an AnalogOut connected to the specified pin
elessair 0:f269e3021894 57 *
elessair 0:f269e3021894 58 * @param AnalogOut pin to connect to (18)
elessair 0:f269e3021894 59 */
elessair 0:f269e3021894 60 AnalogOut(PinName pin) {
elessair 0:f269e3021894 61 analogout_init(&_dac, pin);
elessair 0:f269e3021894 62 }
elessair 0:f269e3021894 63
elessair 0:f269e3021894 64 /** Set the output voltage, specified as a percentage (float)
elessair 0:f269e3021894 65 *
elessair 0:f269e3021894 66 * @param value A floating-point value representing the output voltage,
elessair 0:f269e3021894 67 * specified as a percentage. The value should lie between
elessair 0:f269e3021894 68 * 0.0f (representing 0v / 0%) and 1.0f (representing 3.3v / 100%).
elessair 0:f269e3021894 69 * Values outside this range will be saturated to 0.0f or 1.0f.
elessair 0:f269e3021894 70 */
elessair 0:f269e3021894 71 void write(float value) {
elessair 0:f269e3021894 72 lock();
elessair 0:f269e3021894 73 analogout_write(&_dac, value);
elessair 0:f269e3021894 74 unlock();
elessair 0:f269e3021894 75 }
elessair 0:f269e3021894 76
elessair 0:f269e3021894 77 /** Set the output voltage, represented as an unsigned short in the range [0x0, 0xFFFF]
elessair 0:f269e3021894 78 *
elessair 0:f269e3021894 79 * @param value 16-bit unsigned short representing the output voltage,
elessair 0:f269e3021894 80 * normalised to a 16-bit value (0x0000 = 0v, 0xFFFF = 3.3v)
elessair 0:f269e3021894 81 */
elessair 0:f269e3021894 82 void write_u16(unsigned short value) {
elessair 0:f269e3021894 83 lock();
elessair 0:f269e3021894 84 analogout_write_u16(&_dac, value);
elessair 0:f269e3021894 85 unlock();
elessair 0:f269e3021894 86 }
elessair 0:f269e3021894 87
elessair 0:f269e3021894 88 /** Return the current output voltage setting, measured as a percentage (float)
elessair 0:f269e3021894 89 *
elessair 0:f269e3021894 90 * @returns
elessair 0:f269e3021894 91 * A floating-point value representing the current voltage being output on the pin,
elessair 0:f269e3021894 92 * measured as a percentage. The returned value will lie between
elessair 0:f269e3021894 93 * 0.0f (representing 0v / 0%) and 1.0f (representing 3.3v / 100%).
elessair 0:f269e3021894 94 *
elessair 0:f269e3021894 95 * @note
elessair 0:f269e3021894 96 * This value may not match exactly the value set by a previous write().
elessair 0:f269e3021894 97 */
elessair 0:f269e3021894 98 float read() {
elessair 0:f269e3021894 99 lock();
elessair 0:f269e3021894 100 float ret = analogout_read(&_dac);
elessair 0:f269e3021894 101 unlock();
elessair 0:f269e3021894 102 return ret;
elessair 0:f269e3021894 103 }
elessair 0:f269e3021894 104
elessair 0:f269e3021894 105 /** An operator shorthand for write()
elessair 0:f269e3021894 106 */
elessair 0:f269e3021894 107 AnalogOut& operator= (float percent) {
elessair 0:f269e3021894 108 // Underlying write call is thread safe
elessair 0:f269e3021894 109 write(percent);
elessair 0:f269e3021894 110 return *this;
elessair 0:f269e3021894 111 }
elessair 0:f269e3021894 112
elessair 0:f269e3021894 113 AnalogOut& operator= (AnalogOut& rhs) {
elessair 0:f269e3021894 114 // Underlying write call is thread safe
elessair 0:f269e3021894 115 write(rhs.read());
elessair 0:f269e3021894 116 return *this;
elessair 0:f269e3021894 117 }
elessair 0:f269e3021894 118
elessair 0:f269e3021894 119 /** An operator shorthand for read()
elessair 0:f269e3021894 120 */
elessair 0:f269e3021894 121 operator float() {
elessair 0:f269e3021894 122 // Underlying read call is thread safe
elessair 0:f269e3021894 123 return read();
elessair 0:f269e3021894 124 }
elessair 0:f269e3021894 125
elessair 0:f269e3021894 126 virtual ~AnalogOut() {
elessair 0:f269e3021894 127 // Do nothing
elessair 0:f269e3021894 128 }
elessair 0:f269e3021894 129
elessair 0:f269e3021894 130 protected:
elessair 0:f269e3021894 131
elessair 0:f269e3021894 132 virtual void lock() {
elessair 0:f269e3021894 133 _mutex.lock();
elessair 0:f269e3021894 134 }
elessair 0:f269e3021894 135
elessair 0:f269e3021894 136 virtual void unlock() {
elessair 0:f269e3021894 137 _mutex.unlock();
elessair 0:f269e3021894 138 }
elessair 0:f269e3021894 139
elessair 0:f269e3021894 140 dac_t _dac;
elessair 0:f269e3021894 141 PlatformMutex _mutex;
elessair 0:f269e3021894 142 };
elessair 0:f269e3021894 143
elessair 0:f269e3021894 144 } // namespace mbed
elessair 0:f269e3021894 145
elessair 0:f269e3021894 146 #endif
elessair 0:f269e3021894 147
elessair 0:f269e3021894 148 #endif
elessair 0:f269e3021894 149
elessair 0:f269e3021894 150 /** @}*/