用淘宝买的信号模块9833，然后例子也已经给了51的，但是手头用的是stc8a的，因此简单改造一下，测试买的模块。
测试的结果还是比较好的，就是信号比较弱，所以后面需要加运放等电路。
接线：
VCC接单片机的+5V，DGND接单片机的GND，
三个信号引脚；
测试的示波器的引脚GND接AGND，然后红表笔接OUT。
得到后面的波形。
//---------------------------------------------------//
//AD9833模块测试程序
//功能：循环输出1KHz方波，正弦波。三角波
//接口：DAT --> P1.0
// CLK --> P1.1
// FNC --> P1.2
//---------------------------------------------------//
//定义头文件
# include <reg51.h>
# include <stdio.h>
# include <intrins.h>
sfr P0M0 = 0x94;
sfr P0M1 = 0x93;
sfr P1M0 = 0x92;
sfr P1M1 = 0x91;
sfr P2M0 = 0x96;
sfr P2M1 = 0x95;
sfr P3M0 = 0xb2;
sfr P3M1 = 0xb1;
sfr P4M0 = 0xb4;
sfr P4M1 = 0xb3;
sfr P5M0 = 0xca;
sfr P5M1 = 0xc9;
sfr P6M0 = 0xcc;
sfr P6M1 = 0xcb;
sfr P7M0 = 0xe2;
sfr P7M1 = 0xe1;
//---------------------------------------------------//
sbit ad9833_sdata =P2^2;
sbit ad9833_sclk =P2^3;
sbit ad9833_fsync =P2^4;
//---------------------------------------------------//
//延时程序
//---------------------------------------------------//
void delay(unsigned int m)
{
unsigned int n,tt;
for (n=0;n<=m;n++)
{
for (tt=0;tt<=10;tt++);
}
}
//---------------------------------------------------//
//向AD9833写16位数据
//---------------------------------------------------//
void write_ad9833_d16(unsigned int x)
{
int i,w;
ad9833_sclk=1;
ad9833_fsync=1;
ad9833_fsync=0;
//写16位数据
w=x;
for(i=0;i<16;i++)
{
ad9833_sdata=w&0x8000;
ad9833_sclk=0;
ad9833_sclk=1;
w=w<<1;
}
ad9833_fsync=1;
ad9833_sclk=0;
}
//---------------------------------------------------//
// 主程序 //
//---------------------------------------------------//
main()
{
int i;
P0M0=0x00;
P0M1=0x00;
P1M0=0x00;
P1M1=0x00;
P2M0=0x00;
P2M1=0x00;
P3M0=0x00;
P3M1=0x00;
P0=0XFF;
P1=0XFF;
P2=0XFF;
P3=0XFF;
while(1)
{
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
//寄存器频率0输出1KHz波形
//第一步：复位
//0000 0001 0000 0000
write_ad9833_d16(0x0100); //D8=1,复位AD9833
for(i=0;i<16;i++);
//第二步，设置一次写入的模式
//D15D14=00，选择控制寄存器
//0010 0001 0000 0000
write_ad9833_d16(0x2100); //选择数据一次写入,将D13=1,D12=0
for(i=0;i<16;i++);
//选择频率0寄存器
//第三步，写入低14位
//01 10 1001 1111 0001 D15D14=01，选择频率寄存器0 ；D13-D0 MSB14
write_ad9833_d16(0x69F1); //L14 先写LSB14
for(i=0;i<16;i++);//延时一下
//第四步，写入高14位
//01 00 0000 0000 0000
write_ad9833_d16(0x4000); //H14 写MSB14，频率寄存器0为1KHz
for(i=0;i<16;i++);
//选择频率1寄存器
//第五步，写入低14位
//1001 0011 1110 0011 D15D14=10选择频率寄存器0,01001111100011
write_ad9833_d16(0x93E3); //L14
for(i=0;i<16;i++);
write_ad9833_d16(0x8001); //H14 频率寄存器1为2KHz
for(i=0;i<16;i++);
write_ad9833_d16(0x2000); //芯片进入工作状态,寄存器频率0输出1KHz波形
//寄存器频率1输出2KHz波形
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
write_ad9833_d16(0x2800);
//寄存器频率0输出1KHz三角波波形
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
write_ad9833_d16(0x2002);
//寄存器频率0输出1KHz方波波形
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
write_ad9833_d16(0x2020);
for(i=0;i<16;i++);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
delay(100000);
}
}
```
