hjl240 发表于 2014-11-27 17:39:44

使用mbed开发如何设置时钟频率

使用mbed开发st公司提供的开发板很方便,但是在头文件里没有找到如何设置系统的时钟频率的头文件,该怎么设置呢?





hjl240 发表于 2014-11-27 18:12:54

还有如何设置AD的采样速率?头文件里好像都没有说
/* 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_ANALOGIN_H
#define MBED_ANALOGIN_H

#include "platform.h"

#if DEVICE_ANALOGIN

#include "analogin_api.h"

namespace mbed {

/** An analog input, used for reading the voltage on a pin
*
* Example:
* @code
* // Print messages when the AnalogIn is greater than 50%
*
* #include "mbed.h"
*
* AnalogIn temperature(p20);
*
* int main() {
*   while(1) {
*         if(temperature > 0.5) {
*             printf("Too hot! (%f)", temperature.read());
*         }
*   }
* }
* @endcode
*/
class AnalogIn {

public:

    /** Create an AnalogIn, connected to the specified pin
   *
   * @param pin AnalogIn pin to connect to
   * @param name (optional) A string to identify the object
   */
    AnalogIn(PinName pin) {
      analogin_init(&_adc, pin);
    }

    /** Read the input voltage, represented as a float in the range
   *
   * @returns A floating-point value representing the current input voltage, measured as a percentage
   */
    float read() {
      return analogin_read(&_adc);
    }

    /** Read the input voltage, represented as an unsigned short in the range
   *
   * @returns
   *   16-bit unsigned short representing the current input voltage, normalised to a 16-bit value
   */
    unsigned short read_u16() {
      return analogin_read_u16(&_adc);
    }

#ifdef MBED_OPERATORS
    /** An operator shorthand for read()
   *
   * The float() operator can be used as a shorthand for read() to simplify common code sequences
   *
   * Example:
   * @code
   * float x = volume.read();
   * float x = volume;
   *
   * if(volume.read() > 0.25) { ... }
   * if(volume > 0.25) { ... }
   * @endcode
   */
    operator float() {
      return read();
    }
#endif

protected:
    analogin_t _adc;
};

} // namespace mbed

#endif

#endif

晓枫VS枯叶 发表于 2014-11-27 20:26:55

在线版的mbed编译器上无法更改 时钟频率等一些列的东西,建议使用离线版中更改 底层文件实现!

hjl240 发表于 2014-11-27 20:41:54

晓枫VS枯叶 发表于 2014-11-27 20:26
在线版的mbed编译器上无法更改 时钟频率等一些列的东西,建议使用离线版中更改 底层文件实现! ...

离线版指的是keil?

晓枫VS枯叶 发表于 2014-11-27 20:52:06

现在keil和IAR上都可以编译了,建议使用IAR,编译速度比mdk快一些!
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