added prescaler for 16 bit pwm in LPC1347 target
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Diff: api/AnalogOut.h
- Revision:
- 0:9b334a45a8ff
- Child:
- 144:ef7eb2e8f9f7
diff -r 000000000000 -r 9b334a45a8ff api/AnalogOut.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/api/AnalogOut.h Thu Oct 01 15:25:22 2015 +0300 @@ -0,0 +1,121 @@ +/* mbed Microcontroller Library + * Copyright (c) 2006-2013 ARM Limited + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +#ifndef MBED_ANALOGOUT_H +#define MBED_ANALOGOUT_H + +#include "platform.h" + +#if DEVICE_ANALOGOUT + +#include "analogout_api.h" + +namespace mbed { + +/** An analog output, used for setting the voltage on a pin + * + * Example: + * @code + * // Make a sawtooth output + * + * #include "mbed.h" + * + * AnalogOut tri(p18); + * int main() { + * while(1) { + * tri = tri + 0.01; + * wait_us(1); + * if(tri == 1) { + * tri = 0; + * } + * } + * } + * @endcode + */ +class AnalogOut { + +public: + + /** Create an AnalogOut connected to the specified pin + * + * @param AnalogOut pin to connect to (18) + */ + AnalogOut(PinName pin) { + analogout_init(&_dac, pin); + } + + /** Set the output voltage, specified as a percentage (float) + * + * @param value A floating-point value representing the output voltage, + * specified as a percentage. The value should lie between + * 0.0f (representing 0v / 0%) and 1.0f (representing 3.3v / 100%). + * Values outside this range will be saturated to 0.0f or 1.0f. + */ + void write(float value) { + analogout_write(&_dac, value); + } + + /** Set the output voltage, represented as an unsigned short in the range [0x0, 0xFFFF] + * + * @param value 16-bit unsigned short representing the output voltage, + * normalised to a 16-bit value (0x0000 = 0v, 0xFFFF = 3.3v) + */ + void write_u16(unsigned short value) { + analogout_write_u16(&_dac, value); + } + + /** Return the current output voltage setting, measured as a percentage (float) + * + * @returns + * A floating-point value representing the current voltage being output on the pin, + * measured as a percentage. The returned value will lie between + * 0.0f (representing 0v / 0%) and 1.0f (representing 3.3v / 100%). + * + * @note + * This value may not match exactly the value set by a previous write(). + */ + float read() { + return analogout_read(&_dac); + } + +#ifdef MBED_OPERATORS + /** An operator shorthand for write() + */ + AnalogOut& operator= (float percent) { + write(percent); + return *this; + } + + AnalogOut& operator= (AnalogOut& rhs) { + write(rhs.read()); + return *this; + } + + /** An operator shorthand for read() + */ + operator float() { + return read(); + } +#endif + +protected: + dac_t _dac; +}; + +} // namespace mbed + +#endif + +#endif