STM32 development | ad7606 parallel multi-channel data acquisition

1、 Schematic design reference

2、 Pin description

Pin	explain
AVCC	Analog power supply voltage 4.75 V to 5.25 V
AGND	Simulate
OS0/OS1/OS2	Oversampling mode selection
PAR/SER/BYTE	parallel / Serial / Parallel byte interface selection
STBY	Standby mode
RANGE	Analog input range selection （±10V or ±5V）
CONVST-A / CONVST-B	Start conversion pin , Generally, it is connected in parallel with PWM Function pin
RESET	Reset pin
RD/SCLK	The parallel interface mode is to read the control pin (RD) / Clock input in serial interface mode (SCLK)
CS	Chip selection , Low level active
BUSY	Output busy , Data can be read at low level
FRSTDATA	Digital output , Indicates when to read back data
REF	Reference voltage selection
DB0~DB15	16 Bit read data output

3、 Reference code

#include <stdio.h>
#include <string.h>
#include "stm32f10x.h"
#include "ad7606.h"

//AD7606 Pin configuration 
void AD7606_GPIOConfig(void)
{
    
	GPIO_InitTypeDef GPIO_InitStructure;

	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_GPIOC | RCC_APB2Periph_GPIOD | RCC_APB2Periph_AFIO, ENABLE);
	GPIO_PinRemapConfig(GPIO_Remap_SWJ_Disable, ENABLE);
	//  Allow modification of RTC And backup registers 
	PWR_BackupAccessCmd(ENABLE);
	// Turn off the external low-speed clock ,PC14+PC15 Can be used as ordinary IO
   	RCC_LSEConfig(RCC_LSE_OFF); 
   	// Turn off intrusion detection ,PC13 As ordinary IO
   	BKP_TamperPinCmd(DISABLE);
	
	//----------------------------- AD7606 DATA GPIO ------------------------------
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_All;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
	GPIO_Init(GPIOC, &GPIO_InitStructure);
	//  No modification RTC And backup registers 
	PWR_BackupAccessCmd(DISABLE);
	//------------------------------------ End ------------------------------------

	//ADCS->PB3, OS0->PB7, OS1->PB6, OS2->PB5
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3 | GPIO_Pin_4 | GPIO_Pin_5 | GPIO_Pin_6;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOB, &GPIO_InitStructure);

	//ADREAD->PD2
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOD, &GPIO_InitStructure);

	// COVA->PA8, COVB->PA11, ADRESET->PA13
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOA, &GPIO_InitStructure);

	//ADFIRST->PA14
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_14;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
	GPIO_Init(GPIOA, &GPIO_InitStructure);
}

// Oversampling rate setting 
void AD7606_SetOS(AD7606_OS_E ucOS)
{
    
	switch (ucOS)
	{
    
		case AD_OS_NO: OS2_0(); OS1_0(); OS0_0(); break;
		case AD_OS_X2: OS2_0(); OS1_0(); OS0_1(); break;
		case AD_OS_X4: OS2_0(); OS1_1(); OS0_0(); break;
		case AD_OS_X8: OS2_0(); OS1_1(); OS0_1(); break;
		case AD_OS_X16: OS2_1(); OS1_0(); OS0_0(); break;
		case AD_OS_X32: OS2_1(); OS1_0(); OS0_1(); break;
		case AD_OS_X64: OS2_1(); OS1_1(); OS0_0(); break;
		default: OS2_0(); OS1_0(); OS0_0(); break;
	}
}

//AD7606 initialization 
void AD7606Initialization(void)
{
    
	delay_ms(1);
	AD7606_RESET_0
	AD7606_SetOS(AD_OS_NO);
	AD7606_CS_0
	AD7606_RD_1
	delay_ms(1);
	AD7606Reset();
}

//AD7606 Reset 
void AD7606Reset(void)
{
    
	AD7606_RESET_1;
	delay_us(1);
	AD7606_RESET_0;
	delay_us(1);
}

// Reading data 
void AD7606ReadSample(void)
{
    
	uint8_t i;
	char ad_buffer[20] = {
    0};
	short ad_value[4] = {
    0};

	for(i = 0; i < 4; i++)
	{
    
		AD7606_RD_0
		__NOP();
		
		ad_buffer[i] = READ_AD_DATA;
		
		AD7606_RD_1;
		__NOP();
	}
	sprintf(ad_buffer, "%d %d %d %d ", ad_buffer[0], ad_buffer[1], ad_buffer[2], ad_buffer[3]);
	USART2_SendStr(ad_buffer);
}

// Frequency settings 
void PWM_ModeConfig(uint32_t frequency)
{
    
	uint32_t arr_value, psc_value;

    // Initialize structure 
	GPIO_InitTypeDef	GPIO_InitStructure;
	TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
	TIM_OCInitTypeDef  TIM_OCInitStructure;

    // Turn on the port clock and reset the clock 
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE);
    // Turn on the timer clock 
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);

    // Pin configuration 
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_11;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOA, &GPIO_InitStructure);

	/* * PWM(Hz) = 72MHz / ((ARR + 1) * (PSC + 1)) * ARR(arr_value) -> TIM_Period * PSC(psc_value) -> TIM_Prescaler */
	psc_value = 72 - 1;
	arr_value = SystemCoreClock / (psc_value + 1) / frequency - 1;
	
    // Count value ,TIM_Period + 1
	TIM_TimeBaseStructure.TIM_Period = arr_value;
    // Prescaled value ,TIM_Perscaler + 1
	TIM_TimeBaseStructure.TIM_Prescaler = psc_value;
    // Clock division factor 
	TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
    // Counter counting mode , Count up 
	TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    // Initialize the timer 
	TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);

    //PWM Pattern 
	TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
    // Output enable 
	TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    // Output channel level polarity configuration 
	TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;

    // Output comparison channel 1
	TIM_OCInitStructure.TIM_Pulse = 4;
	TIM_OC1Init(TIM1, &TIM_OCInitStructure);
	TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable);

    // Output comparison channel 4
	TIM_OCInitStructure.TIM_Pulse = 4;
	TIM_OC4Init(TIM1, &TIM_OCInitStructure);
	TIM_OC4PreloadConfig(TIM1, TIM_OCPreload_Enable);

    // Allow or prohibit the timer to work when ARR Write a new value to the buffer of 
	TIM_ARRPreloadConfig(TIM1, ENABLE);

    // Enable timer 
	TIM_Cmd(TIM1, ENABLE);

	// Main output enable , Only valid when using advanced timer 
	TIM_CtrlPWMOutputs(TIM1, ENABLE);
}

//busy Interrupt configuration 
void AD7606_Busy_IRQ(void)
{
    
	EXTI_InitTypeDef   EXTI_InitStructure;
	GPIO_InitTypeDef   GPIO_InitStructure;
	NVIC_InitTypeDef   NVIC_InitStructure;

	/* Enable GPIOA clock */
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
	// Disable debugging interface 
	GPIO_PinRemapConfig(GPIO_Remap_SWJ_Disable, ENABLE);

	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_15;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
	GPIO_Init(GPIOA, &GPIO_InitStructure);

	GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource15);

	EXTI_InitStructure.EXTI_Line = EXTI_Line15;
	EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
	EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
	EXTI_InitStructure.EXTI_LineCmd = ENABLE;
	EXTI_Init(&EXTI_InitStructure);

	NVIC_InitStructure.NVIC_IRQChannel = EXTI15_10_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
	NVIC_Init(&NVIC_InitStructure);
}

4、 The header file

#ifndef _AD7606_H_
#define _AD7606_H_

#include "stm32f01x.h"

#define READ_AD_DATA GPIO_ReadInputData(GPIOC)

#define OS0_1() GPIO_SetBits(GPIOB, GPIO_Pin_6);
#define OS0_0() GPIO_ResetBits(GPIOB, GPIO_Pin_6);
#define OS1_1() GPIO_SetBits(GPIOB, GPIO_Pin_5);
#define OS1_0() GPIO_ResetBits(GPIOB, GPIO_Pin_5);
#define OS2_1() GPIO_SetBits(GPIOB, GPIO_Pin_4);
#define OS2_0() GPIO_ResetBits(GPIOB, GPIO_Pin_4);

#define AD7606_CS_1 GPIO_SetBits(GPIOB, GPIO_Pin_3);
#define AD7606_CS_0 GPIO_ResetBits(GPIOB, GPIO_Pin_3);
#define AD7606_RD_1 GPIO_SetBits(GPIOD, GPIO_Pin_2);
#define AD7606_RD_0 GPIO_ResetBits(GPIOD, GPIO_Pin_2);


#define AD7606_RESET_1 GPIO_SetBits(GPIOA, GPIO_Pin_13);
#define AD7606_RESET_0 GPIO_ResetBits(GPIOA, GPIO_Pin_13);
#define AD7606_CONVST_1 GPIO_SetBits(GPIOA, GPIO_Pin_8 | GPIO_Pin_11);
#define AD7606_CONVST_0 GPIO_ResetBits(GPIOA, GPIO_Pin_8 | GPIO_Pin_11);

#define AD7606_BUSY_STATE GPIO_ReadInputDataBit(GPIOA, GPIO_Pin_15)
#define AD7606_FRSTDATA_STATE GPIO_ReadInputDataBit(GPIOA, GPIO_Pin_14)

typedef enum
{
    
	AD_OS_NO = 0,
	AD_OS_X2 = 1,
	AD_OS_X4 = 2,
	AD_OS_X8 = 3,
	AD_OS_X16 = 4,
	AD_OS_X32 = 5,
	AD_OS_X64 = 6
	
}AD7606_OS_E;

void AD7606Initialization(void);
void AD7606Reset(void);
void AD7606ReadSample(void);
void AD7606_GPIOConfig(void);
void AD7606_PWM_ModeConfig(uint32_t frequency);
void AD7606_SetOS(uint8_t _ucOS);
void AD7606_Busy_IRQ(void);
void AD7606_IRQ_Disable(void);
void AD7606_IRQ_Enable(void);

#endif /*_AD7606_H*/

Serial transmission can be found in this article

5、 application

#include "stm32f10x.h"
#include "ad7606.h"

int main(void)
{
    	
	AD7606Initialization();
	// Frequency settings 20k
	AD7606_PWM_ModeConfig(20000);
	// Set and enter interrupt 
	AD7606_Busy_IRQ();

	while(1)
	{
    

	}
}

// Interrupt service function 
void EXTI15_10_IRQHandler(void)
{
    
  if(EXTI_GetITStatus(EXTI_Line15) != RESET)
	{
    
		AD7606ReadSample();
    	EXTI_ClearITPendingBit(EXTI_Line15);
	}
}

6、 Download Chinese resources

link ：https://pan.baidu.com/s/1l4AseVGhHjZcd0mLW5btLQ
Extraction code ：a0ko