Yihui Xiong / mbed-src-nrf51822

customized mbed library sources for nrf51822

Dependents:   Grove_Node Potentiometer BLE_Beacon I2C_Scanner

api/AnalogOut.h@0:700cadd8b708, 2014-11-04 (annotated)

Committer:
yihui
Date:
Tue Nov 04 07:38:53 2014 +0000
Revision:
0:700cadd8b708
customized mbed-src library for nrf51822

Who changed what in which revision?

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yihui 0:700cadd8b708 1 /* mbed Microcontroller Library
yihui 0:700cadd8b708 2 * Copyright (c) 2006-2013 ARM Limited
yihui 0:700cadd8b708 3 *
yihui 0:700cadd8b708 4 * Licensed under the Apache License, Version 2.0 (the "License");
yihui 0:700cadd8b708 5 * you may not use this file except in compliance with the License.
yihui 0:700cadd8b708 6 * You may obtain a copy of the License at
yihui 0:700cadd8b708 7 *
yihui 0:700cadd8b708 8 * http://www.apache.org/licenses/LICENSE-2.0
yihui 0:700cadd8b708 9 *
yihui 0:700cadd8b708 10 * Unless required by applicable law or agreed to in writing, software
yihui 0:700cadd8b708 11 * distributed under the License is distributed on an "AS IS" BASIS,
yihui 0:700cadd8b708 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
yihui 0:700cadd8b708 13 * See the License for the specific language governing permissions and
yihui 0:700cadd8b708 14 * limitations under the License.
yihui 0:700cadd8b708 15 */
yihui 0:700cadd8b708 16 #ifndef MBED_ANALOGOUT_H
yihui 0:700cadd8b708 17 #define MBED_ANALOGOUT_H
yihui 0:700cadd8b708 18
yihui 0:700cadd8b708 19 #include "platform.h"
yihui 0:700cadd8b708 20
yihui 0:700cadd8b708 21 #if DEVICE_ANALOGOUT
yihui 0:700cadd8b708 22
yihui 0:700cadd8b708 23 #include "analogout_api.h"
yihui 0:700cadd8b708 24
yihui 0:700cadd8b708 25 namespace mbed {
yihui 0:700cadd8b708 26
yihui 0:700cadd8b708 27 /** An analog output, used for setting the voltage on a pin
yihui 0:700cadd8b708 28 *
yihui 0:700cadd8b708 29 * Example:
yihui 0:700cadd8b708 30 * @code
yihui 0:700cadd8b708 31 * // Make a sawtooth output
yihui 0:700cadd8b708 32 *
yihui 0:700cadd8b708 33 * #include "mbed.h"
yihui 0:700cadd8b708 34 *
yihui 0:700cadd8b708 35 * AnalogOut tri(p18);
yihui 0:700cadd8b708 36 * int main() {
yihui 0:700cadd8b708 37 * while(1) {
yihui 0:700cadd8b708 38 * tri = tri + 0.01;
yihui 0:700cadd8b708 39 * wait_us(1);
yihui 0:700cadd8b708 40 * if(tri == 1) {
yihui 0:700cadd8b708 41 * tri = 0;
yihui 0:700cadd8b708 42 * }
yihui 0:700cadd8b708 43 * }
yihui 0:700cadd8b708 44 * }
yihui 0:700cadd8b708 45 * @endcode
yihui 0:700cadd8b708 46 */
yihui 0:700cadd8b708 47 class AnalogOut {
yihui 0:700cadd8b708 48
yihui 0:700cadd8b708 49 public:
yihui 0:700cadd8b708 50
yihui 0:700cadd8b708 51 /** Create an AnalogOut connected to the specified pin
yihui 0:700cadd8b708 52 *
yihui 0:700cadd8b708 53 * @param AnalogOut pin to connect to (18)
yihui 0:700cadd8b708 54 */
yihui 0:700cadd8b708 55 AnalogOut(PinName pin) {
yihui 0:700cadd8b708 56 analogout_init(&_dac, pin);
yihui 0:700cadd8b708 57 }
yihui 0:700cadd8b708 58
yihui 0:700cadd8b708 59 /** Set the output voltage, specified as a percentage (float)
yihui 0:700cadd8b708 60 *
yihui 0:700cadd8b708 61 * @param value A floating-point value representing the output voltage,
yihui 0:700cadd8b708 62 * specified as a percentage. The value should lie between
yihui 0:700cadd8b708 63 * 0.0f (representing 0v / 0%) and 1.0f (representing 3.3v / 100%).
yihui 0:700cadd8b708 64 * Values outside this range will be saturated to 0.0f or 1.0f.
yihui 0:700cadd8b708 65 */
yihui 0:700cadd8b708 66 void write(float value) {
yihui 0:700cadd8b708 67 analogout_write(&_dac, value);
yihui 0:700cadd8b708 68 }
yihui 0:700cadd8b708 69
yihui 0:700cadd8b708 70 /** Set the output voltage, represented as an unsigned short in the range [0x0, 0xFFFF]
yihui 0:700cadd8b708 71 *
yihui 0:700cadd8b708 72 * @param value 16-bit unsigned short representing the output voltage,
yihui 0:700cadd8b708 73 * normalised to a 16-bit value (0x0000 = 0v, 0xFFFF = 3.3v)
yihui 0:700cadd8b708 74 */
yihui 0:700cadd8b708 75 void write_u16(unsigned short value) {
yihui 0:700cadd8b708 76 analogout_write_u16(&_dac, value);
yihui 0:700cadd8b708 77 }
yihui 0:700cadd8b708 78
yihui 0:700cadd8b708 79 /** Return the current output voltage setting, measured as a percentage (float)
yihui 0:700cadd8b708 80 *
yihui 0:700cadd8b708 81 * @returns
yihui 0:700cadd8b708 82 * A floating-point value representing the current voltage being output on the pin,
yihui 0:700cadd8b708 83 * measured as a percentage. The returned value will lie between
yihui 0:700cadd8b708 84 * 0.0f (representing 0v / 0%) and 1.0f (representing 3.3v / 100%).
yihui 0:700cadd8b708 85 *
yihui 0:700cadd8b708 86 * @note
yihui 0:700cadd8b708 87 * This value may not match exactly the value set by a previous write().
yihui 0:700cadd8b708 88 */
yihui 0:700cadd8b708 89 float read() {
yihui 0:700cadd8b708 90 return analogout_read(&_dac);
yihui 0:700cadd8b708 91 }
yihui 0:700cadd8b708 92
yihui 0:700cadd8b708 93 #ifdef MBED_OPERATORS
yihui 0:700cadd8b708 94 /** An operator shorthand for write()
yihui 0:700cadd8b708 95 */
yihui 0:700cadd8b708 96 AnalogOut& operator= (float percent) {
yihui 0:700cadd8b708 97 write(percent);
yihui 0:700cadd8b708 98 return *this;
yihui 0:700cadd8b708 99 }
yihui 0:700cadd8b708 100
yihui 0:700cadd8b708 101 AnalogOut& operator= (AnalogOut& rhs) {
yihui 0:700cadd8b708 102 write(rhs.read());
yihui 0:700cadd8b708 103 return *this;
yihui 0:700cadd8b708 104 }
yihui 0:700cadd8b708 105
yihui 0:700cadd8b708 106 /** An operator shorthand for read()
yihui 0:700cadd8b708 107 */
yihui 0:700cadd8b708 108 operator float() {
yihui 0:700cadd8b708 109 return read();
yihui 0:700cadd8b708 110 }
yihui 0:700cadd8b708 111 #endif
yihui 0:700cadd8b708 112
yihui 0:700cadd8b708 113 protected:
yihui 0:700cadd8b708 114 dac_t _dac;
yihui 0:700cadd8b708 115 };
yihui 0:700cadd8b708 116
yihui 0:700cadd8b708 117 } // namespace mbed
yihui 0:700cadd8b708 118
yihui 0:700cadd8b708 119 #endif
yihui 0:700cadd8b708 120
yihui 0:700cadd8b708 121 #endif