solijoli
Newbie level 1
Hello, I'm trying to control the AD9833 waveform generator circuit with the STM32F4 board via SPI. I've written the code below. I'm able to generate the desired waveforms for the signal but I can't change the frequency or the phase. Can you tell me what is wrong with the code and how can it be fixed. I also think that there might be a problem about initializing the AD9833 but I couldn't tell for sure. The datasheet can be seen from the link below. Thanks for helping!!
https://www.analog.com/static/imported-files/data_sheets/AD9833.pdf
https://www.analog.com/static/imported-files/data_sheets/AD9833.pdf
Code:
#include "stm32f4xx.h"
#include "stm32f4xx_rcc.h"
#include "stm32f4xx_gpio.h"
#include "stm32f4xx_spi.h"
#define AD_F_MCLK 25000000
#define AD_2POW28 268435456
#define AD_FREQ_CALC(freq) (uint32_t)(((double)AD_2POW28/(double)AD_F_MCLK*freq)*4)
#define AD_PHASE_CALC(phase_deg) (uint16_t)((512*phase_deg)/45)
#define AD_B28 13
#define AD_HLB 12
#define AD_FSELECT 11
#define AD_PSELECT 10
#define AD_RESET 8
#define AD_SLEEP1 7
#define AD_SLEEP12 6
#define AD_OPBITEN 5
#define AD_DIV2 3
#define AD_MODE 1
#define AD_OFF 0
#define AD_TRIANGLE 1
#define AD_SQUARE 2
#define AD_SINE 3
#define AD_FREQ0 (1<<14)
#define AD_FREQ1 (1<<15)
#define AD_PHASE0 (3<<14)
#define AD_PHASE1 ((3<<14)|(1<<13))
typedef struct {
uint8_t freq_out;
uint8_t phase_out;
uint8_t mode;
uint16_t command_reg;
} ad9833_settings_t;
typedef struct {
float freq[2];
float phase[2];
float mod_freq;
} ad9833_settings_f;
ad9833_settings_t ad_settings;
ad9833_settings_f ad_settings2;
void delay(__IO uint32_t nCount)
{
while(nCount--)
{
}
}
static void AD9833_word(uint16_t data)
{
SPI1->DR = (data>>8); // High 8 bits, MSB first
while(!(SPI1->SR & SPI_I2S_FLAG_TXE));
while( SPI1->SR & SPI_I2S_FLAG_BSY );
SPI1->DR = (uint8_t) data; // Low 8 bits
while(!(SPI1->SR & SPI_I2S_FLAG_TXE));
while( SPI1->SR & SPI_I2S_FLAG_BSY );
}
static void AD9833_write(uint16_t data)
{
GPIO_ResetBits(GPIOE, GPIO_Pin_7);
delay(0xFF);
AD9833_word(data);
delay(0xFF);
GPIO_SetBits(GPIOE, GPIO_Pin_7);
}
void AD9833_setFreq(uint8_t reg, double freq){
uint32_t freq_reg;
uint16_t reg_reg; //probably should be renamed...
freq_reg = AD_FREQ_CALC(freq);
ad_settings2.freq[reg] = freq;
if (reg==1)
reg_reg = AD_FREQ1;
else
reg_reg = AD_FREQ0;
GPIO_ResetBits(GPIOE, GPIO_Pin_7);
delay(0xFF);
AD9833_word(reg_reg | (0x3FFF&(uint16_t)(freq_reg>>2 )));
AD9833_word(reg_reg | (0x3FFF&(uint16_t)(freq_reg>>16)));
delay(0xFF);
GPIO_SetBits(GPIOE, GPIO_Pin_7);
}
void AD9833_setFreqOut(uint8_t freq_out){
ad_settings.freq_out = freq_out;
switch (freq_out){
case 0:
ad_settings.command_reg &= ~(1<<AD_FSELECT);
break;
case 1:
ad_settings.command_reg |= (1<<AD_FSELECT);
break;
case 2:
//TODO
break;
}
AD9833_write(ad_settings.command_reg);
}
double AD9833_getFreq(uint8_t reg){
return ad_settings2.freq[reg];
}
void AD9833_setPhase(uint8_t reg, double phase){
uint16_t reg_reg; //probably should be renamed...
if (reg==1)
reg_reg = AD_PHASE1;
else
reg_reg = AD_PHASE0;
ad_settings2.phase[reg] = phase;
AD9833_write(reg_reg | AD_PHASE_CALC(ad_settings2.phase[reg]));
}
void AD9833_setPhaseOut(uint8_t phase_out){
ad_settings.phase_out = phase_out;
switch (phase_out){
case 0:
ad_settings.command_reg &= ~(1<<AD_PSELECT);
break;
case 1:
ad_settings.command_reg |= (1<<AD_PSELECT);
break;
case 2:
//TODO
break;
}
AD9833_write(ad_settings.command_reg);
}
void AD9833_setMode(uint8_t mode)
{
ad_settings.mode = mode;
switch(mode)
{
case AD_OFF:
ad_settings.command_reg |= (1<<AD_SLEEP12);
ad_settings.command_reg |= (1<<AD_SLEEP1);
break;
case AD_TRIANGLE:
ad_settings.command_reg &= ~(1<<AD_OPBITEN);
ad_settings.command_reg |= (1<<AD_MODE);
ad_settings.command_reg &= ~(1<<AD_SLEEP12);
ad_settings.command_reg &= ~(1<<AD_SLEEP1);
break;
case AD_SQUARE:
ad_settings.command_reg |= (1<<AD_OPBITEN);
ad_settings.command_reg &= ~(1<<AD_MODE);
ad_settings.command_reg |= (1<<AD_DIV2);
ad_settings.command_reg &= ~(1<<AD_SLEEP12);
ad_settings.command_reg &= ~(1<<AD_SLEEP1);
break;
case AD_SINE:
ad_settings.command_reg &= ~(1<<AD_OPBITEN);
ad_settings.command_reg &= ~(1<<AD_MODE);
ad_settings.command_reg &= ~(1<<AD_SLEEP12);
ad_settings.command_reg &= ~(1<<AD_SLEEP1);
break;
}
AD9833_write(ad_settings.command_reg); // Send selected MODE to AD9833
}
void init_SPI1(void)
{
GPIO_InitTypeDef GPIO_InitStruct;
SPI_InitTypeDef SPI_InitStruct;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
/* configure pins used by SPI1
* PA5 = SCK
* PA6 = MISO
* PA7 = MOSI
*/
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_7 | GPIO_Pin_5;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOA, &GPIO_InitStruct);
// connect SPI1 pins to SPI alternate function
GPIO_PinAFConfig(GPIOA, GPIO_PinSource5, GPIO_AF_SPI1);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource7, GPIO_AF_SPI1);
// enable clock for used IO pins
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOE, ENABLE);
/* Configure the chip select pin
in this case we will use PE7 */
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_7;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_Init(GPIOE, &GPIO_InitStruct);
GPIOE->BSRRL |= GPIO_Pin_7; // set PE7 high
// enable peripheral clock
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);
/* configure SPI1 in Mode 2
* CPOL = 1 --> clock is high when idle
* CPHA = 0 --> data is sampled at the first edge
*/
SPI_InitStruct.SPI_Direction = SPI_Direction_1Line_Tx;
SPI_InitStruct.SPI_Mode = SPI_Mode_Master; // transmit in master mode, NSS pin has to be always high
SPI_InitStruct.SPI_DataSize = SPI_DataSize_16b; // one packet of data is 8 bits wide
SPI_InitStruct.SPI_CPOL = SPI_CPOL_High; // clock is low when idle
SPI_InitStruct.SPI_CPHA = SPI_CPHA_1Edge; // data sampled at first edge
SPI_InitStruct.SPI_NSS = SPI_NSS_Soft | SPI_NSSInternalSoft_Set;
SPI_InitStruct.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_4; // SPI frequency is APB2 frequency / 4
SPI_InitStruct.SPI_FirstBit = SPI_FirstBit_MSB;// data is transmitted MSB first
SPI_Init(SPI1, &SPI_InitStruct);
SPI_Cmd(SPI1, ENABLE); // enable SPI1
}
int main(void) {
init_SPI1();
AD9833_setFreq(0, 100);
AD9833_setFreqOut(0);
AD9833_setMode(AD_SQUARE);
while(1){
}
}