}
else
{
f_temp=un_prev_data-aun_red_buffer[i];
f_temp/=(un_max-un_min);
f_temp*=MAX_BRIGHTNESS;
n_brightness+=(int)f_temp;
if(n_brightness>MAX_BRIGHTNESS)
n_brightness=MAX_BRIGHTNESS;
}
//send samples and calculation result to terminal program through UART
if(ch_hr_valid == 1 && n_heart_rate<120)//**/ ch_hr_valid == 1 && ch_spo2_valid ==1 && n_heart_rate<120 && n_sp02<101
{
dis_hr = n_heart_rate;
dis_spo2 = n_sp02;
}
else
{
dis_hr = 0;
dis_spo2 = 0;
}
printf("HR=%i, ", n_heart_rate);
printf("HRvalid=%i, ", ch_hr_valid);
printf("SpO2=%i, ", n_sp02);
printf("SPO2Valid=%i\r\n", ch_spo2_valid);
}
maxim_heart_rate_and_oxygen_saturation(aun_ir_buffer, n_ir_buffer_length, aun_red_buffer, &n_sp02, &ch_spo2_valid, &n_heart_rate, &ch_hr_valid);
}
}
### max30102.c
#include "max30102.h" #include "myiic.h" #include "delay.h"
u8 max30102_Bus_Write(u8 Register_Address, u8 Word_Data) {
/* 采用串行EEPROM随即读取指令序列，连续读取若干字节 */
/* 第1步：发起I2C总线启动信号 */
IIC_Start();
/* 第2步：发起控制字节，高7bit是地址，bit0是读写控制位，0表示写，1表示读 */
IIC_Send_Byte(max30102_WR_address | I2C_WR); /* 此处是写指令 */
/* 第3步：发送ACK */
if (IIC_Wait_Ack() != 0)
{
goto cmd_fail; /* EEPROM器件无应答 */
}
/* 第4步：发送字节地址 */
IIC_Send_Byte(Register_Address);
if (IIC_Wait_Ack() != 0)
{
goto cmd_fail; /* EEPROM器件无应答 */
}
/* 第5步：开始写入数据 */
IIC_Send_Byte(Word_Data);
/* 第6步：发送ACK */
if (IIC_Wait_Ack() != 0)
{
goto cmd_fail; /* EEPROM器件无应答 */
}
/* 发送I2C总线停止信号 */
IIC_Stop();
return 1; /* 执行成功 */
cmd_fail: /* 命令执行失败后，切记发送停止信号，避免影响I2C总线上其他设备 / / 发送I2C总线停止信号 */ IIC_Stop(); return 0; }
u8 max30102_Bus_Read(u8 Register_Address) { u8 data;
/* 第1步：发起I2C总线启动信号 */
IIC_Start();
/* 第2步：发起控制字节，高7bit是地址，bit0是读写控制位，0表示写，1表示读 */
IIC_Send_Byte(max30102_WR_address | I2C_WR); /* 此处是写指令 */
/* 第3步：发送ACK */
if (IIC_Wait_Ack() != 0)
{
goto cmd_fail; /* EEPROM器件无应答 */
}
/* 第4步：发送字节地址， */
IIC_Send_Byte((uint8_t)Register_Address);
if (IIC_Wait_Ack() != 0)
{
goto cmd_fail; /* EEPROM器件无应答 */
}
/* 第6步：重新启动I2C总线。下面开始读取数据 */
IIC_Start();
/* 第7步：发起控制字节，高7bit是地址，bit0是读写控制位，0表示写，1表示读 */
IIC_Send_Byte(max30102_WR_address | I2C_RD); /* 此处是读指令 */
/* 第8步：发送ACK */
if (IIC_Wait_Ack() != 0)
{
goto cmd_fail; /* EEPROM器件无应答 */
}
/* 第9步：读取数据 */
{
data = IIC_Read_Byte(0); /* 读1个字节 */
IIC_NAck(); /* 最后1个字节读完后，CPU产生NACK信号(驱动SDA = 1) */
}
/* 发送I2C总线停止信号 */
IIC_Stop();
return data; /* 执行成功 返回data值 */
cmd_fail: /* 命令执行失败后，切记发送停止信号，避免影响I2C总线上其他设备 / / 发送I2C总线停止信号 */ IIC_Stop(); return 0; }
void max30102_FIFO_ReadWords(u8 Register_Address,u16 Word_Data[][2],u8 count) { u8 i=0; u8 no = count; u8 data1, data2; /* 第1步：发起I2C总线启动信号 */ IIC_Start();
/* 第2步：发起控制字节，高7bit是地址，bit0是读写控制位，0表示写，1表示读 */
IIC_Send_Byte(max30102_WR_address | I2C_WR); /* 此处是写指令 */
/* 第3步：发送ACK */
if (IIC_Wait_Ack() != 0)
{
goto cmd_fail; /* EEPROM器件无应答 */
}
/* 第4步：发送字节地址， */
IIC_Send_Byte((uint8_t)Register_Address);
if (IIC_Wait_Ack() != 0)
{
goto cmd_fail; /* EEPROM器件无应答 */
}
/* 第6步：重新启动I2C总线。下面开始读取数据 */
IIC_Start();
/* 第7步：发起控制字节，高7bit是地址，bit0是读写控制位，0表示写，1表示读 */
IIC_Send_Byte(max30102_WR_address | I2C_RD); /* 此处是读指令 */
/* 第8步：发送ACK */
if (IIC_Wait_Ack() != 0)
{
goto cmd_fail; /* EEPROM器件无应答 */
}
/* 第9步：读取数据 */
while (no)
{
data1 = IIC_Read_Byte(0);
IIC_Ack();
data2 = IIC_Read_Byte(0);
IIC_Ack();
Word_Data[i][0] = (((u16)data1 << 8) | data2); //
data1 = IIC_Read_Byte(0);
IIC_Ack();
data2 = IIC_Read_Byte(0);
if(1==no)
IIC_NAck(); /* 最后1个字节读完后，CPU产生NACK信号(驱动SDA = 1) */
else
IIC_Ack();
Word_Data[i][1] = (((u16)data1 << 8) | data2);
no--;
i++;
}
/* 发送I2C总线停止信号 */
IIC_Stop();
cmd_fail: /* 命令执行失败后，切记发送停止信号，避免影响I2C总线上其他设备 / / 发送I2C总线停止信号 */ IIC_Stop(); }
void max30102_FIFO_ReadBytes(u8 Register_Address,u8* Data) { max30102_Bus_Read(REG_INTR_STATUS_1); max30102_Bus_Read(REG_INTR_STATUS_2);
/* 第1步：发起I2C总线启动信号 */
IIC_Start();
/* 第2步：发起控制字节，高7bit是地址，bit0是读写控制位，0表示写，1表示读 */
IIC_Send_Byte(max30102_WR_address | I2C_WR); /* 此处是写指令 */
/* 第3步：发送ACK */
if (IIC_Wait_Ack() != 0)
{
goto cmd_fail; /* EEPROM器件无应答 */
}
/* 第4步：发送字节地址， */
IIC_Send_Byte((uint8_t)Register_Address);
if (IIC_Wait_Ack() != 0)
{
goto cmd_fail; /* EEPROM器件无应答 */
}
/* 第6步：重新启动I2C总线。下面开始读取数据 */
IIC_Start();
/* 第7步：发起控制字节，高7bit是地址，bit0是读写控制位，0表示写，1表示读 */
IIC_Send_Byte(max30102_WR_address | I2C_RD); /* 此处是读指令 */
/* 第8步：发送ACK */
if (IIC_Wait_Ack() != 0)
{
goto cmd_fail; /* EEPROM器件无应答 */
}
/* 第9步：读取数据 */
Data[0] = IIC_Read_Byte(1);
Data[1] = IIC_Read_Byte(1);
Data[2] = IIC_Read_Byte(1);
Data[3] = IIC_Read_Byte(1);
Data[4] = IIC_Read_Byte(1);
Data[5] = IIC_Read_Byte(0);
/* 最后1个字节读完后，CPU产生NACK信号(驱动SDA = 1) */
/* 发送I2C总线停止信号 */
IIC_Stop();
cmd_fail: /* 命令执行失败后，切记发送停止信号，避免影响I2C总线上其他设备 / / 发送I2C总线停止信号 */ IIC_Stop();
// u8 i; // u8 fifo_wr_ptr; // u8 firo_rd_ptr; // u8 number_tp_read; // //Get the FIFO_WR_PTR // fifo_wr_ptr = max30102_Bus_Read(REG_FIFO_WR_PTR); // //Get the FIFO_RD_PTR // firo_rd_ptr = max30102_Bus_Read(REG_FIFO_RD_PTR); // // number_tp_read = fifo_wr_ptr - firo_rd_ptr; // // //for(i=0;i<number_tp_read;i++){ // if(number_tp_read>0){ // IIC_ReadBytes(max30102_WR_address,REG_FIFO_DATA,Data,6); // }
//max30102_Bus_Write(REG_FIFO_RD_PTR,fifo_wr_ptr);
}
void max30102_init(void) { GPIO_InitTypeDef GPIO_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB,ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_14;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
GPIO_Init(GPIOB, &GPIO_InitStructure);
IIC_Init();
max30102_reset();
// max30102_Bus_Write(REG_MODE_CONFIG, 0x0b); //mode configuration : temp_en[3] MODE[2:0]=010 HR only enabled 011 SP02 enabled // max30102_Bus_Write(REG_INTR_STATUS_2, 0xF0); //open all of interrupt // max30102_Bus_Write(REG_INTR_STATUS_1, 0x00); //all interrupt clear // max30102_Bus_Write(REG_INTR_ENABLE_2, 0x02); //DIE_TEMP_RDY_EN // max30102_Bus_Write(REG_TEMP_CONFIG, 0x01); //SET TEMP_EN
// max30102_Bus_Write(REG_SPO2_CONFIG, 0x47); //SPO2_SR[4:2]=001 100 per second LED_PW[1:0]=11 16BITS
// max30102_Bus_Write(REG_LED1_PA, 0x47); // max30102_Bus_Write(REG_LED2_PA, 0x47);
max30102_Bus_Write(REG_INTR_ENABLE_1,0xc0); // INTR setting
max30102_Bus_Write(REG_INTR_ENABLE_2,0x00);
max30102_Bus_Write(REG_FIFO_WR_PTR,0x00); //FIFO_WR_PTR[4:0]
max30102_Bus_Write(REG_OVF_COUNTER,0x00); //OVF_COUNTER[4:0]
max30102_Bus_Write(REG_FIFO_RD_PTR,0x00); //FIFO_RD_PTR[4:0]
max30102_Bus_Write(REG_FIFO_CONFIG,0x0f); //sample avg = 1, fifo rollover=false, fifo almost full = 17
max30102_Bus_Write(REG_MODE_CONFIG,0x03); //0x02 for Red only, 0x03 for SpO2 mode 0x07 multimode LED
max30102_Bus_Write(REG_SPO2_CONFIG,0x27); // SPO2_ADC range = 4096nA, SPO2 sample rate (100 Hz), LED pulseWidth (400uS)
max30102_Bus_Write(REG_LED1_PA,0x24); //Choose value for ~ 7mA for LED1
max30102_Bus_Write(REG_LED2_PA,0x24); // Choose value for ~ 7mA for LED2
max30102_Bus_Write(REG_PILOT_PA,0x7f); // Choose value for ~ 25mA for Pilot LED
// // Interrupt Enable 1 Register. Set PPG_RDY_EN (data available in FIFO) // max30102_Bus_Write(0x2, 1<<6);
// // FIFO configuration register // // SMP_AVE: 16 samples averaged per FIFO sample // // FIFO_ROLLOVER_EN=1 // //max30102_Bus_Write(0x8, 1<<4); // max30102_Bus_Write(0x8, (0<<5) | 1<<4);
// // Mode Configuration Register // // SPO2 mode // max30102_Bus_Write(0x9, 3);
// // SPO2 Configuration Register // max30102_Bus_Write(0xa, // (3<<5) // SPO2_ADC_RGE 2 = full scale 8192 nA (LSB size 31.25pA); 3 = 16384nA // | (1<<2) // sample rate: 0 = 50sps; 1 = 100sps; 2 = 200sps // | (3<<0) // LED_PW 3 = 411μs, ADC resolution 18 bits // );
// // LED1 (red) power (0 = 0mA; 255 = 50mA) // max30102_Bus_Write(0xc, 0xb0);
// // LED (IR) power // max30102_Bus_Write(0xd, 0xa0);
}
void max30102_reset(void) { max30102_Bus_Write(REG_MODE_CONFIG,0x40); max30102_Bus_Write(REG_MODE_CONFIG,0x40); }
void maxim_max30102_write_reg(uint8_t uch_addr, uint8_t uch_data) { // char ach_i2c_data[2]; // ach_i2c_data[0]=uch_addr; // ach_i2c_data[1]=uch_data; // // IIC_WriteBytes(I2C_WRITE_ADDR, ach_i2c_data, 2); IIC_Write_One_Byte(I2C_WRITE_ADDR,uch_addr,uch_data); }
void maxim_max30102_read_reg(uint8_t uch_addr, uint8_t *puch_data)
{
// char ch_i2c_data;
// ch_i2c_data=uch_addr;
// IIC_WriteBytes(I2C_WRITE_ADDR, &ch_i2c_data, 1);
//
// i2c.read(I2C_READ_ADDR, &ch_i2c_data, 1);
//
// *puch_data=(uint8_t) ch_i2c_data;
IIC_Read_One_Byte(I2C_WRITE_ADDR,uch_addr,puch_data);
}
void maxim_max30102_read_fifo(uint32_t *pun_red_led, uint32_t *pun_ir_led) { uint32_t un_temp; unsigned char uch_temp; char ach_i2c_data[6]; *pun_red_led=0; *pun_ir_led=0;
//read and clear status register maxim_max30102_read_reg(REG_INTR_STATUS_1, &uch_temp); maxim_max30102_read_reg(REG_INTR_STATUS_2, &uch_temp);
IIC_ReadBytes(I2C_WRITE_ADDR,REG_FIFO_DATA,(u8 *)ach_i2c_data,6);
un_temp=(unsigned char) ach_i2c_data[0]; un_temp<<=16; *pun_red_led+=un_temp; un_temp=(unsigned char) ach_i2c_data[1]; un_temp<<=8; *pun_red_led+=un_temp; un_temp=(unsigned char) ach_i2c_data[2]; *pun_red_led+=un_temp;
un_temp=(unsigned char) ach_i2c_data[3]; un_temp<<=16; *pun_ir_led+=un_temp; un_temp=(unsigned char) ach_i2c_data[4]; un_temp<<=8; *pun_ir_led+=un_temp; un_temp=(unsigned char) ach_i2c_data[5]; *pun_ir_led+=un_temp; *pun_red_led&=0x03FFFF; //Mask MSB [23:18] *pun_ir_led&=0x03FFFF; //Mask MSB [23:18] }
### max30102.h
#ifndef __MYIIC_H #define __MYIIC_H #include "sys.h" //
#define MAX30102_INT PBin(9)
#define I2C_WR 0 /* 写控制bit / #define I2C_RD 1 / 读控制bit */
#define max30102_WR_address 0xAE
#define I2C_WRITE_ADDR 0xAE #define I2C_READ_ADDR 0xAF
//register addresses #define REG_INTR_STATUS_1 0x00 #define REG_INTR_STATUS_2 0x01 #define REG_INTR_ENABLE_1 0x02 #define REG_INTR_ENABLE_2 0x03 #define REG_FIFO_WR_PTR 0x04 #define REG_OVF_COUNTER 0x05 #define REG_FIFO_RD_PTR 0x06 #define REG_FIFO_DATA 0x07 #define REG_FIFO_CONFIG 0x08 #define REG_MODE_CONFIG 0x09 #define REG_SPO2_CONFIG 0x0A #define REG_LED1_PA 0x0C #define REG_LED2_PA 0x0D #define REG_PILOT_PA 0x10 #define REG_MULTI_LED_CTRL1 0x11 #define REG_MULTI_LED_CTRL2 0x12 #define REG_TEMP_INTR 0x1F #define REG_TEMP_FRAC 0x20 #define REG_TEMP_CONFIG 0x21 #define REG_PROX_INT_THRESH 0x30 #define REG_REV_ID 0xFE #define REG_PART_ID 0xFF
void max30102_init(void);
void max30102_reset(void);
u8 max30102_Bus_Write(u8 Register_Address, u8 Word_Data);
u8 max30102_Bus_Read(u8 Register_Address);
void max30102_FIFO_ReadWords(u8 Register_Address,u16 Word_Data[][2],u8 count);
void max30102_FIFO_ReadBytes(u8 Register_Address,u8* Data);
void maxim_max30102_write_reg(uint8_t uch_addr, uint8_t uch_data); void maxim_max30102_read_reg(uint8_t uch_addr, uint8_t *puch_data); void maxim_max30102_read_fifo(uint32_t *pun_red_led, uint32_t *pun_ir_led); #endif
### myiic.c
#include "myiic.h" #include "delay.h"
//初始化IIC void IIC_Init(void) { GPIO_InitTypeDef GPIO_InitStructure; //RCC->APB2ENR|=1<<4;//先使能外设IO PORTC时钟 RCC_APB2PeriphClockCmd( RCC_APB2Periph_GPIOB, ENABLE );
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7|GPIO_Pin_8;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP ; //推挽输出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStructure);
IIC_SCL=1;
IIC_SDA=1;
}
//产生IIC起始信号
void IIC_Start(void)
{
SDA_OUT(); //sda线输出
IIC_SDA=1;
IIC_SCL=1;
delay_us(4);
IIC_SDA=0;//START:when CLK is high,DATA change form high to low
delay_us(4);
IIC_SCL=0;//钳住I2C总线，准备发送或接收数据
}
//产生IIC停止信号
void IIC_Stop(void)
{
SDA_OUT();//sda线输出
IIC_SCL=0;
IIC_SDA=0;//STOP:when CLK is high DATA change form low to high
delay_us(4);
IIC_SCL=1;
IIC_SDA=1;//发送I2C总线结束信号
delay_us(4);
}
//等待应答信号到来
//返回值：1，接收应答失败
// 0，接收应答成功
u8 IIC_Wait_Ack(void)
{
u8 ucErrTime=0;
SDA_IN(); //SDA设置为输入
IIC_SDA=1;delay_us(1);
IIC_SCL=1;delay_us(1);
while(READ_SDA)
{
ucErrTime++;
if(ucErrTime>250)
{
IIC_Stop();
return 1;
}
}
IIC_SCL=0;//时钟输出0
return 0;
}
//产生ACK应答
void IIC_Ack(void)
{
IIC_SCL=0;
SDA_OUT();
IIC_SDA=0;
delay_us(2);
IIC_SCL=1;
delay_us(2);
IIC_SCL=0;
}
//不产生ACK应答
void IIC_NAck(void)
{
IIC_SCL=0;
SDA_OUT();
IIC_SDA=1;
delay_us(2);
IIC_SCL=1;
delay_us(2);
IIC_SCL=0;
}
//IIC发送一个字节
//返回从机有无应答
//1，有应答
//0，无应答
void IIC_Send_Byte(u8 txd)
{
u8 t;
SDA_OUT();
IIC_SCL=0;//拉低时钟开始数据传输
for(t=0;t<8;t++)
{
IIC_SDA=(txd&0x80)>>7;
txd<<=1;
delay_us(2); //对TEA5767这三个延时都是必须的
IIC_SCL=1;
delay_us(2);
IIC_SCL=0;
delay_us(2);
}
}
//读1个字节，ack=1时，发送ACK，ack=0，发送nACK
u8 IIC_Read_Byte(unsigned char ack)
{
unsigned char i,receive=0;
SDA_IN();//SDA设置为输入
for(i=0;i<8;i++ )
{
IIC_SCL=0;
delay_us(2);
IIC_SCL=1;
receive<<=1;
if(READ_SDA)receive++;
delay_us(1);
}
if (!ack)
IIC_NAck();//发送nACK
else
IIC_Ack(); //发送ACK
return receive;
}
void IIC_WriteBytes(u8 WriteAddr,u8* data,u8 dataLength) { u8 i; IIC_Start();
IIC_Send_Byte(WriteAddr); //发送写命令
IIC_Wait_Ack();
for(i=0;i<dataLength;i++)
{
IIC_Send_Byte(data[i]);
IIC_Wait_Ack();
}
IIC_Stop();//产生一个停止条件
delay_ms(10);
}
void IIC_ReadBytes(u8 deviceAddr, u8 writeAddr,u8* data,u8 dataLength) { u8 i; IIC_Start();
IIC_Send_Byte(deviceAddr); //发送写命令
IIC_Wait_Ack();
IIC_Send_Byte(writeAddr);
IIC_Wait_Ack();
IIC_Send_Byte(deviceAddr|0X01);//进入接收模式
IIC_Wait_Ack();
for(i=0;i<dataLength-1;i++)
{
data[i] = IIC_Read_Byte(1);
}
data[dataLength-1] = IIC_Read_Byte(0);
IIC_Stop();//产生一个停止条件
delay_ms(10);
}
void IIC_Read_One_Byte(u8 daddr,u8 addr,u8* data) { IIC_Start();
IIC_Send_Byte(daddr); //发送写命令
IIC_Wait_Ack();
IIC_Send_Byte(addr);//发送地址
IIC_Wait_Ack();
IIC_Start();
IIC_Send_Byte(daddr|0X01);//进入接收模式
IIC_Wait_Ack();
*data = IIC_Read_Byte(0);
IIC_Stop();//产生一个停止条件
}
void IIC_Write_One_Byte(u8 daddr,u8 addr,u8 data) { IIC_Start();
IIC_Send_Byte(daddr); //发送写命令
IIC_Wait_Ack();
IIC_Send_Byte(addr);//发送地址
IIC_Wait_Ack();
IIC_Send_Byte(data); //发送字节
IIC_Wait_Ack();
IIC_Stop();//产生一个停止条件
delay_ms(10);
}
### myiic.h
#ifndef __MAX30102_H #define __MAX30102_H #include "sys.h" //
//IO方向设置 #define SDA_IN() {GPIOB->CRH&=0XFFFFFFF0;GPIOB->CRH|=4;} #define SDA_OUT() {GPIOB->CRH&=0XFFFFFFF0;GPIOB->CRH|=7;}
//IO操作函数 #define IIC_SCL PBout(7) //SCL #define IIC_SDA PBout(8) //SDA #define READ_SDA PBin(8) //输入SDA
//IIC所有操作函数 void IIC_Init(void); //初始化IIC的IO口 void IIC_Start(void); //发送IIC开始信号 void IIC_Stop(void); //发送IIC停止信号 void IIC_Send_Byte(u8 txd); //IIC发送一个字节 u8 IIC_Read_Byte(unsigned char ack);//IIC读取一个字节 u8 IIC_Wait_Ack(void); //IIC等待ACK信号 void IIC_Ack(void); //IIC发送ACK信号 void IIC_NAck(void); //IIC不发送ACK信号
void IIC_Write_One_Byte(u8 daddr,u8 addr,u8 data); void IIC_Read_One_Byte(u8 daddr,u8 addr,u8* data);
void IIC_WriteBytes(u8 WriteAddr,u8* data,u8 dataLength); void IIC_ReadBytes(u8 deviceAddr, u8 writeAddr,u8* data,u8 dataLength); #endif
### algorithm.c
/** \file algorithm.c ****************************************************** *
- Project: MAXREFDES117#
- Filename: algorithm.cpp
- Description: This module calculates the heart rate/SpO2 level
-
- This code follows the following naming conventions:
- char ch_pmod_value
- char (array) s_pmod_s_string[16]
- float f_pmod_value
- int32_t n_pmod_value
- int32_t (array) an_pmod_value[16]
- int16_t w_pmod_value
- int16_t (array) aw_pmod_value[16]
- uint16_t uw_pmod_value
- uint16_t (array) auw_pmod_value[16]
- uint8_t uch_pmod_value
- uint8_t (array) auch_pmod_buffer[16]
- uint32_t un_pmod_value
- int32_t * pn_pmod_value
- ------------------------------------------------------------------------- / /******************************************************************************
- Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved.
- Permission is hereby granted, free of charge, to any person obtaining a
- copy of this software and associated documentation files (the "Software"),
- to deal in the Software without restriction, including without limitation
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- and/or sell copies of the Software, and to permit persons to whom the
- Software is furnished to do so, subject to the following conditions:
- The above copyright notice and this permission notice shall be included
- in all copies or substantial portions of the Software.
- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
- OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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- IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
- OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
- ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
- OTHER DEALINGS IN THE SOFTWARE.
- Except as contained in this notice, the name of Maxim Integrated
- Products, Inc. shall not be used except as stated in the Maxim Integrated
- Products, Inc. Branding Policy.
- The mere transfer of this software does not imply any licenses
- of trade secrets, proprietary technology, copyrights, patents,
- trademarks, maskwork rights, or any other form of intellectual
- property whatsoever. Maxim Integrated Products, Inc. retains all
- ownership rights.
*/ #include "algorithm.h"
const uint16_t auw_hamm[31]={ 41, 276, 512, 276, 41 }; //Hamm= long16(512* hamming(5)'); //uch_spo2_table is computed as -45.060ratioAverage ratioAverage + 30.354 *ratioAverage + 94.845 ; const uint8_t uch_spo2_table[184]={ 95, 95, 95, 96, 96, 96, 97, 97, 97, 97, 97, 98, 98, 98, 98, 98, 99, 99, 99, 99, 99, 99, 99, 99, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 99, 99, 99, 99, 99, 99, 99, 99, 98, 98, 98, 98, 98, 98, 97, 97, 97, 97, 96, 96, 96, 96, 95, 95, 95, 94, 94, 94, 93, 93, 93, 92, 92, 92, 91, 91, 90, 90, 89, 89, 89, 88, 88, 87, 87, 86, 86, 85, 85, 84, 84, 83, 82, 82, 81, 81, 80, 80, 79, 78, 78, 77, 76, 76, 75, 74, 74, 73, 72, 72, 71, 70, 69, 69, 68, 67, 66, 66, 65, 64, 63, 62, 62, 61, 60, 59, 58, 57, 56, 56, 55, 54, 53, 52, 51, 50, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 31, 30, 29, 28, 27, 26, 25, 23, 22, 21, 20, 19, 17, 16, 15, 14, 12, 11, 10, 9, 7, 6, 5, 3, 2, 1 } ; static int32_t an_dx[ BUFFER_SIZE-MA4_SIZE]; // delta static int32_t an_x[ BUFFER_SIZE]; //ir static int32_t an_y[ BUFFER_SIZE]; //red
void maxim_heart_rate_and_oxygen_saturation(uint32_t *pun_ir_buffer, int32_t n_ir_buffer_length, uint32_t *pun_red_buffer, int32_t *pn_spo2, int8_t *pch_spo2_valid, int32_t pn_heart_rate, int8_t pch_hr_valid) /
-
\brief Calculate the heart rate and SpO2 level
-
\par Details
-
By detecting peaks of PPG cycle and corresponding AC/DC of red/infra-red signal, the ratio for the SPO2 is computed. -
Since this algorithm is aiming for Arm M0/M3. formaula for SPO2 did not achieve the accuracy due to register overflow. -
Thus, accurate SPO2 is precalculated and save longo uch_spo2_table[] per each ratio. -
\param[in] *pun_ir_buffer - IR sensor data buffer
-
\param[in] n_ir_buffer_length - IR sensor data buffer length
-
\param[in] *pun_red_buffer - Red sensor data buffer
-
\param[out] *pn_spo2 - Calculated SpO2 value
-
\param[out] *pch_spo2_valid - 1 if the calculated SpO2 value is valid
-
\param[out] *pn_heart_rate - Calculated heart rate value
-
\param[out] *pch_hr_valid - 1 if the calculated heart rate value is valid
-
\retval None */ { uint32_t un_ir_mean ,un_only_once ; int32_t k ,n_i_ratio_count; int32_t i, s, m, n_exact_ir_valley_locs_count ,n_middle_idx; int32_t n_th1, n_npks,n_c_min;
int32_t an_ir_valley_locs[15] ; int32_t an_exact_ir_valley_locs[15] ; int32_t an_dx_peak_locs[15] ; int32_t n_peak_interval_sum;int32_t n_y_ac, n_x_ac; int32_t n_spo2_calc; int32_t n_y_dc_max, n_x_dc_max; int32_t n_y_dc_max_idx, n_x_dc_max_idx; int32_t an_ratio[5],n_ratio_average; int32_t n_nume, n_denom ; // remove DC of ir signal
un_ir_mean =0; for (k=0 ; k<n_ir_buffer_length ; k++ ) un_ir_mean += pun_ir_buffer[k] ; un_ir_mean =un_ir_mean/n_ir_buffer_length ; for (k=0 ; k<n_ir_buffer_length ; k++ ) an_x[k] = pun_ir_buffer[k] - un_ir_mean ;// 4 pt Moving Average for(k=0; k< BUFFER_SIZE-MA4_SIZE; k++){ n_denom= ( an_x[k]+an_x[k+1]+ an_x[k+2]+ an_x[k+3]); an_x[k]= n_denom/(int32_t)4; }
// get difference of smoothed IR signal
for( k=0; k<BUFFER_SIZE-MA4_SIZE-1; k++) an_dx[k]= (an_x[k+1]- an_x[k]);
// 2-pt Moving Average to an_dx for(k=0; k< BUFFER_SIZE-MA4_SIZE-2; k++){ an_dx[k] = ( an_dx[k]+an_dx[k+1])/2 ; }
// hamming window // flip wave form so that we can detect valley with peak detector for ( i=0 ; i<BUFFER_SIZE-HAMMING_SIZE-MA4_SIZE-2 ;i++){ s= 0; for( k=i; k<i+ HAMMING_SIZE ;k++){ s -= an_dx[k] *auw_hamm[k-i] ; } an_dx[i]= s/ (int32_t)1146; // divide by sum of auw_hamm }
n_th1=0; // threshold calculation for ( k=0 ; k<BUFFER_SIZE-HAMMING_SIZE ;k++){ n_th1 += ((an_dx[k]>0)? an_dx[k] : ((int32_t)0-an_dx[k])) ; } n_th1= n_th1/ ( BUFFER_SIZE-HAMMING_SIZE); // peak location is acutally index for sharpest location of raw signal since we flipped the signal
maxim_find_peaks( an_dx_peak_locs, &n_npks, an_dx, BUFFER_SIZE-HAMMING_SIZE, n_th1, 8, 5 );//peak_height, peak_distance, max_num_peaksn_peak_interval_sum =0; if (n_npks>=2){ for (k=1; k<n_npks; k++) n_peak_interval_sum += (an_dx_peak_locs[k]-an_dx_peak_locs[k -1]); n_peak_interval_sum=n_peak_interval_sum/(n_npks-1); *pn_heart_rate=(int32_t)(6000/n_peak_interval_sum);// beats per minutes *pch_hr_valid = 1; } else { *pn_heart_rate = -999; *pch_hr_valid = 0; }
for ( k=0 ; k<n_npks ;k++) an_ir_valley_locs[k]=an_dx_peak_locs[k]+HAMMING_SIZE/2;
// raw value : RED(=y) and IR(=X) // we need to assess DC and AC value of ir and red PPG. for (k=0 ; k<n_ir_buffer_length ; k++ ) { an_x[k] = pun_ir_buffer[k] ; an_y[k] = pun_red_buffer[k] ; }
// find precise min near an_ir_valley_locs n_exact_ir_valley_locs_count =0; for(k=0 ; k<n_npks ;k++){ un_only_once =1; m=an_ir_valley_locs[k]; n_c_min= 16777216;//2^24; if (m+5 < BUFFER_SIZE-HAMMING_SIZE && m-5 >0){ for(i= m-5;i<m+5; i++) if (an_x[i]<n_c_min){ if (un_only_once >0){ un_only_once =0; } n_c_min= an_x[i] ; an_exact_ir_valley_locs[k]=i; } if (un_only_once ==0) n_exact_ir_valley_locs_count ++ ; } } if (n_exact_ir_valley_locs_count <2 ){ *pn_spo2 = -999 ; // do not use SPO2 since signal ratio is out of range *pch_spo2_valid = 0; return; } // 4 pt MA for(k=0; k< BUFFER_SIZE-MA4_SIZE; k++){ an_x[k]=( an_x[k]+an_x[k+1]+ an_x[k+2]+ an_x[k+3])/(int32_t)4; an_y[k]=( an_y[k]+an_y[k+1]+ an_y[k+2]+ an_y[k+3])/(int32_t)4; }
//using an_exact_ir_valley_locs , find ir-red DC andir-red AC for SPO2 calibration ratio //finding AC/DC maximum of raw ir * red between two valley locations n_ratio_average =0; n_i_ratio_count =0;
for(k=0; k< 5; k++) an_ratio[k]=0; for (k=0; k< n_exact_ir_valley_locs_count; k++){ if (an_exact_ir_valley_locs[k] > BUFFER_SIZE ){
*pn_spo2 = -999 ; // do not use SPO2 since valley loc is out of range *pch_spo2_valid = 0; return; } } // find max between two valley locations // and use ratio betwen AC compoent of Ir & Red and DC compoent of Ir & Red for SPO2for (k=0; k< n_exact_ir_valley_locs_count-1; k++){ n_y_dc_max= -16777216 ; n_x_dc_max= - 16777216; if (an_exact_ir_valley_locs[k+1]-an_exact_ir_valley_locs[k] >10){ for (i=an_exact_ir_valley_locs[k]; i< an_exact_ir_valley_locs[k+1]; i++){ if (an_x[i]> n_x_dc_max) {n_x_dc_max =an_x[i];n_x_dc_max_idx =i; } if (an_y[i]> n_y_dc_max) {n_y_dc_max =an_y[i];n_y_dc_max_idx=i;} } n_y_ac= (an_y[an_exact_ir_valley_locs[k+1]] - an_y[an_exact_ir_valley_locs[k] ] )*(n_y_dc_max_idx -an_exact_ir_valley_locs[k]); //red n_y_ac= an_y[an_exact_ir_valley_locs[k]] + n_y_ac/ (an_exact_ir_valley_locs[k+1] - an_exact_ir_valley_locs[k]) ;
n_y_ac= an_y[n_y_dc_max_idx] - n_y_ac; // subracting linear DC compoenents from raw n_x_ac= (an_x[an_exact_ir_valley_locs[k+1]] - an_x[an_exact_ir_valley_locs[k] ] )*(n_x_dc_max_idx -an_exact_ir_valley_locs[k]); // ir n_x_ac= an_x[an_exact_ir_valley_locs[k]] + n_x_ac/ (an_exact_ir_valley_locs[k+1] - an_exact_ir_valley_locs[k]); n_x_ac= an_x[n_y_dc_max_idx] - n_x_ac; // subracting linear DC compoenents from raw n_nume=( n_y_ac *n_x_dc_max)>>7 ; //prepare X100 to preserve floating value n_denom= ( n_x_ac *n_y_dc_max)>>7; if (n_denom>0 && n_i_ratio_count <5 && n_nume != 0) { an_ratio[n_i_ratio_count]= (n_nume*20)/n_denom ; //formular is ( n_y_ac *n_x_dc_max) / ( n_x_ac *n_y_dc_max) ; ///*************************n_nume原来是*100************************// n_i_ratio_count++; } }}
maxim_sort_ascend(an_ratio, n_i_ratio_count); n_middle_idx= n_i_ratio_count/2;
if (n_middle_idx >1) n_ratio_average =( an_ratio[n_middle_idx-1] +an_ratio[n_middle_idx])/2; // use median else n_ratio_average = an_ratio[n_middle_idx ];
if( n_ratio_average>2 && n_ratio_average <184){ n_spo2_calc= uch_spo2_table[n_ratio_average] ; pn_spo2 = n_spo2_calc ; pch_spo2_valid = 1;// float_SPO2 = -45.060n_ratio_average n_ratio_average/10000 + 30.354 *n_ratio_average/100 + 94.845 ; // for comparison with table } else{ *pn_spo2 = -999 ; // do not use SPO2 since signal ratio is out of range *pch_spo2_valid = 0; } }
void maxim_find_peaks(int32_t *pn_locs, int32_t pn_npks, int32_t pn_x, int32_t n_size, int32_t n_min_height, int32_t n_min_distance, int32_t n_max_num) /
- \brief Find peaks
- \par Details
-
Find at most MAX_NUM peaks above MIN_HEIGHT separated by at least MIN_DISTANCE - \retval None */ { maxim_peaks_above_min_height( pn_locs, pn_npks, pn_x, n_size, n_min_height ); maxim_remove_close_peaks( pn_locs, pn_npks, pn_x, n_min_distance ); *pn_npks = min( *pn_npks, n_max_num );
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