STM32 实现二维码解码

一个国外朋友实现的关于STM32F417解析二维码的代码，移植了开源库ZXing，可以成功实现二维码的解析。非常好的设计参考资源

/**
  ******************************************************************************
  * @file    system_stm32f4xx.c
  * @author  MCD Application Team
  * @version V1.0.2
  * @date    05-March-2012
  * @brief   CMSIS Cortex-M4 Device Peripheral Access layer System Source File.
  *          This file contains the system clock configuration for STM32F4xx devices
  *          and is generated by the clock configuration tool
  *          stm32f4xx_Clock_Configuration_V1.0.1.xls
  *             
  * 1.  This file provides two functions and one global variable to be called from 
  *     user application:
  *      - SystemInit（）: Setups the system clock （System clock source PLL Multiplier
  *                      and Divider factors AHB/APBx prescalers and Flash settings）
  *                      depending on the configuration made in the clock xls tool. 
  *                      This function is called at startup just after reset and 
  *                      before branch to main program. This call is made inside
  *                      the “startup_stm32f4xx.s“ file.
  *
  *      - SystemCoreClock variable: Contains the core clock （HCLK） it can be used
  *                                  by the user application to setup the SysTick 
  *                                  timer or configure other parameters.
  *                                     
  *      - SystemCoreClockUpdate（）: Updates the variable SystemCoreClock and must
  *                                 be called whenever the core clock is changed
  *                                 during program execution.
  *
  * 2. After each device reset the HSI （16 MHz） is used as system clock source.
  *    Then SystemInit（） function is called in “startup_stm32f4xx.s“ file to
  *    configure the system clock before to branch to main program.
  *
  * 3. If the system clock source selected by user fails to startup the SystemInit（）
  *    function will do nothing and HSI still used as system clock source. User can 
  *    add some code to deal with this issue inside the SetSysClock（） function.
  *
  * 4. The default value of HSE crystal is set to 25MHz refer to “HSE_VALUE“ define
  *    in “stm32f4xx.h“ file. When HSE is used as system clock source directly or
  *    through PLL and you are using different crystal you have to adapt the HSE
  *    value to your own configuration.
  *
  * 5. This file configures the system clock as follows:
  *=============================================================================
  *=============================================================================
  *        Supported STM32F4xx device revision    | Rev A
  *-----------------------------------------------------------------------------
  *        System Clock source                    | PLL （HSE）
  *-----------------------------------------------------------------------------
  *        SYSCLK（Hz）                             | 168000000
  *------------------------------------------------------

 属性            大小     日期    时间   名称
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     目录           0  2013-12-12 13:54  qr-scanner-test-master\
     目录           0  2013-12-12 13:54  qr-scanner-test-master\Libraries\
     目录           0  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\
     文件       51511  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\CMSIS END USER LICENCE AGREEMENT.pdf
     目录           0  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Device\
     目录           0  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Device\ST\
     目录           0  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Device\ST\STM32F4xx\
     目录           0  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Device\ST\STM32F4xx\Include\
     文件      523850  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Device\ST\STM32F4xx\Include\stm32f4xx.h
     文件        3128  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Device\ST\STM32F4xx\Include\system_stm32f4xx.h
     文件       20407  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Device\ST\STM32F4xx\Release_Notes.html
     目录           0  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Device\ST\STM32F4xx\Source\
     目录           0  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Device\ST\STM32F4xx\Source\Templates\
     目录           0  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Device\ST\STM32F4xx\Source\Templates\arm\
     文件       29203  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Device\ST\STM32F4xx\Source\Templates\arm\startup_stm32f4xx.s
     目录           0  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Device\ST\STM32F4xx\Source\Templates\iar\
     文件       24043  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Device\ST\STM32F4xx\Source\Templates\iar\startup_stm32f4xx.s
     文件       21297  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Device\ST\STM32F4xx\Source\Templates\system_stm32f4xx.c
     目录           0  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Documentation\
     文件       13369  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Documentation\CMSIS-SVD_Schema_1_0.xsd
     文件      123611  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Documentation\CMSIS_CM4_SIMD.htm
     文件       63937  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Documentation\CMSIS_Core.htm
     文件        9717  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Documentation\CMSIS_DebugSupport.htm
     文件       17391  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Documentation\CMSIS_History.htm
     文件      123676  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Documentation\CMSIS_Logo_Final.jpg
     文件       66130  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Documentation\CMSIS_System_View_Description.htm
     目录           0  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Include\
     文件        1085  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Include\arm_common_tables.h
     文件      233275  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Include\arm_math.h
     文件       31283  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Include\core_cm0.h
     文件       68486  2013-12-12 13:54  qr-scanner-test-master\Libraries\CMSIS\Include\core_cm3.h
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