/**
  @page AnalogVoltageMonitoring COMP Analog voltage monitoring example
  
  @verbatim
  ******************** (C) COPYRIGHT 2012 STMicroelectronics *******************
  * @file    COMP/AnalogVoltageMonitoring/readme.txt 
  * @author  MCD Application Team
  * @version V1.1.1
  * @date    13-April-2012
  * @brief   Description of the COMP Analog voltage monitoring example.
  ******************************************************************************
  *
  * Licensed under MCD-ST Liberty SW License Agreement V2, (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.st.com/software_license_agreement_liberty_v2
  *
  * 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.
  *
  ******************************************************************************
   @endverbatim

@par Example Description 

  In some applications, it is recommended to power-on ADC1 only if it is required 
  since it can jeopardize battery life time if left powered-on continuously. 
  In this example, COMP2 is used to monitor the analog voltage while the MCU 
  is in stop mode and to wake-up the system if a predefined threshold is crossed.
  When the analog voltage crosses the threshold, the COMP2 is powered-off and
  ADC1 is powered-on to perform continuous conversion.

  MCU is switching between two modes: 
    - If analog voltage is above the internal reference voltage (VREFINT), 
      ADC1 is powered-on and continuous conversion is performed of channel 18 (PB12)
      for STM32L152_EVAL and performed of channel 31 (PF10) for STM32L152D_EVAL :
      MCU is in run mode, LD1 is OFF and measured voltage is displayed on 
      LCD Glass and color LCD for STM32L152_EVAL and on only color LCD for 
      STM32L152D_EVAL.
    - If analog voltage is under VREFINT, ADC1 is powered-off and COMP2 is 
      powered-on, the MCU enters stop mode and LD1 is ON.

  COMP2 is configured as following:
    - Inverting input is VREFINT: this is the selected threshold
    - Non Inverting input is connected to PB5
    - Edge detection config is rising edge

@par Directory contents 

  - COMP/AnalogVoltageMonitoring/stm32l1xx_conf.h     Library Configuration file
  - COMP/AnalogVoltageMonitoring/stm32l1xx_it.c       Interrupt handlers
  - COMP/AnalogVoltageMonitoring/stm32l1xx_it.h       Header for stm32l1xx_it.c
  - COMP/AnalogVoltageMonitoring/main.c               Main program
  - COMP/AnalogVoltageMonitoring/main.h               Main Header file
  - COMP/AnalogVoltageMonitoring/system_stm32l1xx.c   STM32L1xx system source file

@note The "system_stm32l1xx.c" is generated by an automatic clock configuration 
      system and can be easily customized to your own configuration. 
      To select different clock setup, use the "STM32L1xx_Clock_Configuration_V1.1.0.xls" 
      provided with the AN3309 package available on <a href="http://www.st.com/internet/mcu/family/141.jsp">  ST Microcontrollers </a>

@par Hardware and Software environment

  - This example runs on STM32L1xx Ultra Low Power High-, Medium-Density and Medium-Density Plus Devices.

  - This example has been tested with STMicroelectronics STM32L152D-EVAL (STM32L1xx 
    Ultra Low Power High-Density) and STM32L152-EVAL (STM32L1xx Ultra Low 
    Power Medium-Density) evaluation board and can be easily tailored to any 
    other supported device and development board.


  - STM32L152-EVAL Set-up
    - Connect a variable power supply 0-3.3V to both: ADC Channel18 mapped on pin PB.12
      (potentiometer RV3) and COMP2 inverting input mapped on pin PB5.
    @note Using Jumper JP17, connect one jumper in PB12 and another in PB5 
          position. Thus PB5 and PB12 are both connected to RV3.
    - Remove jumper JP11
    - Make sure that JP10 is in TRST position

  - STM32L152D-EVAL Set-up
   - Connect a variable power supply 0-3.3V to both: ADC Channel31 mapped on pin PF.10
     (potentiometer RV3) and COMP2 inverting input mapped on pin PB5.
    @note Using Jumper JP13, connect one jumper in ADC and another in COM_IN+ 
          position. Thus PB5 and PF10 are both connected to RV3.
    - Remove jumper JP14
     
@par How to use it ? 

In order to make the program work, you must do the following :
 - Copy all source files from this example folder to the template folder under
   Project\STM32L1xx_StdPeriph_Templates
 - Open your preferred toolchain 
 - Rebuild all files and load your image into target memory
 - Run the example

@note
- Ultra Low Power Medium-density devices are STM32L151xx and STM32L152xx 
  microcontrollers where the Flash memory density ranges between 64 and 128 Kbytes.
- Ultra Low Power Medium-density Plus devices are STM32L151xx, STM32L152xx and 
  STM32L162xx microcontrollers where the Flash memory density is 256 Kbytes.
- Ultra Low Power High-density devices are STM32L151xx, STM32L152xx and STM32L162xx 
  microcontrollers where the Flash memory density is 384 Kbytes.
    
 * <h3><center>&copy; COPYRIGHT STMicroelectronics</center></h3>
 */


