MXCHIP+Core1081的ADC

今天跑了下V1.19中 ADC的实验。将Analog Test Board 插入Open1081 的SPI口 。 （注：Analog Test Board 本身不带有ADC芯片，只是用于测试MCU自带的AD/DA功能 ）

用MDK软件打开 ADC 的工程，配置，编译，下载运行

发现每隔一秒就会输出一个测量值，
用手旋转Analog Test Board上的电位器，串口输出 AD1 的采样值，同时Open1081 板上的4个用户LED 闪烁频率会相应改变。
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打开简单浏览了下V1.19中 ADC实验的main.c代码 ，发现MX1081 的 ADC 功能上手较容易。
关键代码：
·················
#define ADC1_DR_Address ((u32)0x4001204C) // 指定使用ADC1
··················
main()
{ ·····
ADC1_CH1_DMA_Config(); // 配置ADC1的参数 采用DMA模式
ADC_SoftwareStartConv(ADC1);// 启动ADC
·····
AD_value_1 = ADC_ConvertedValue[0]; //得到采样值的值
·····}

可以看出ST的库函数，已经把ADC 采样、转换 、传输等功能函数已经都编写好了，我们只需设置一下就可以正常使用了。
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突然对MX1081 的 ADC 有点兴趣，就查询MX1081的相关资料找到：

大概得出：MX1081 内部集成的STM32F205RG 内嵌3个12位的ADC,每个ADC共用8个外部通道。 STM32的ADC是逐次比较型ADC。
更多信息可以参看 stm32f2xx_adc.c

在STM32中，使用ADC时往往采用DMA传输方式，由DMA把ADC外设转换的数据传输到SRAM，再进行处理，甚至直接把ADC外设转换的数据转移到串口发送给上位机。

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简单修改了下 main.c中代码，让其测电源压值 。
while(1)
{
/* Printf message with AD value to serial port every 1 second */
printf("\r\n****************************************************************\r\n");
AD_value_1 = ADC_ConvertedValue[0];
AD_value_1=(float) ADC_ConvertedValue[0]/4096*3.3;
printf("The current AD1 value = %f v\r\n",AD_value_1);
}

运行效果为：