【2018 LPC54114双核挑战赛】驱动DDS AD9833

哈佛祖安智 · 发表于 2018-5-27 15:04:19

项目需要用到DDS芯片产生可调频的高精度正弦信号，

ad9833驱动比较简单，只需要3个IO即可，片选、数据、时钟，这里我使用PIO0_11作为时钟，PIO0_12作为数据、PIO0_14作为片选。采用模拟SPI方式。

#include "app_ad9833.h"
#include "app_ioctl.h"
#define AD9833_SYSTEM_CLOCK 25000000UL
#define FSYNC_0() do {gpio_out_low(0,12);} while(0)
#define FSYNC_1() do {gpio_out_high(0,12);} while(0)
#define SCLK_0() do {gpio_out_low(0,11);} while(0)
#define SCLK_1() do {gpio_out_high(0,11);} while(0)
#define SDATA_0() do {gpio_out_low(0,14);} while(0)
#define SDATA_1() do {gpio_out_high(0,14);} while(0)
void ad9833_init(void)
{
gpio_out_init(0,12,1);//ss
gpio_out_init(0,14,0);//data
gpio_out_init(0,11,0);//sck
}
void AD9833_Write_16Bits(uint16_t _cmd)
{
uint8_t i;
SCLK_1();
FSYNC_0();
for(i = 0; i < 16; i++)
{
if (_cmd & 0x8000)
{
SDATA_1();
}
else
{
SDATA_0();
}
SCLK_0();
_cmd <<= 1;
SCLK_1();
}
FSYNC_1();
}
/*
*********************************************************************************************************
* 函数名：AD9833_SelectWave
* 功能说明：软件位控制
* IOUT正弦波，SIGNBITOUT方波，写FREQREG0 ，写PHASE0
* ad9833_write_16bit(0x2028) 一次性写FREQREG0
* ad9833_write_16bit(0x0038) 单独改写FREQREG0的LSB
* ad9833_write_16bit(0x1038) 单独改写FREQREG0的MSB
* IOUT三角波，写PHASE0
* ad9833_write_16bit(0x2002)一次性写FREQREG0
* ad9833_write_16bit(0x0002)单独改写FREQREG0的LSB
* ad9833_write_16bit(0x1008)单独改写FREQREG0的MSB
* 形参：_Type -- 波形类型
* 返回值：无
*********************************************************************************************************
*/
void AD9833_SelectWave(uint8_t _Type)
{
FSYNC_1(); //宏定义
SCLK_1();
if(_Type == 0)
{
AD9833_Write_16Bits(0x2028); /*频率寄存器输出方波*/
}
else if(_Type == 1)
{
AD9833_Write_16Bits(0x2002); /*频率寄存器输出三角波*/
}
else if(_Type == 2)
{
AD9833_Write_16Bits(0x2000); /*频率寄存器输出正弦波*/
}
else if(_Type == 3)
{
AD9833_Write_16Bits(0x00C0); /*无输出*/
}
}
/****************************************************************
函数名称: AD9833_SetFreq
功能: 设置频率值
参数: _freq
freq -- 频率值 (Freq_value(value)=Freq_data(data)*FCLK/2^28)
返回值: 无
*****************************************************************/
void AD9833_SetFreq(uint32_t _freq)
{
uint32_t freq;
uint16_t lsb_14bit;
uint16_t msb_14bit;
uint8_t freq_number = 0;
freq = (uint32_t)(268435456.0 / AD9833_SYSTEM_CLOCK * _freq);
lsb_14bit = (uint16_t)freq;
msb_14bit = (uint16_t)(freq >> 14);
if(freq_number == FREQ_0)
{
lsb_14bit &= ~(1U<<15);
lsb_14bit |= 1<<14;
msb_14bit &= ~(1U<<15);
msb_14bit |= 1<<14;
}
else
{
lsb_14bit &= ~(1<<14);
lsb_14bit |= 1U<<15;
msb_14bit &= ~(1<<14);
msb_14bit |= 1U<<15;
}
AD9833_Write_16Bits(lsb_14bit);
AD9833_Write_16Bits(msb_14bit);
}

复制代码

附上工程：

LPC54114-AD9833.zip (1.08 MB, 下载次数: 20)

[LPC双核挑战赛] 【2018 LPC54114双核挑战赛】驱动DDS AD9833

站长推荐 /4