Bluetooth health management device based on stm32

1.  Preface

With the development of mobile communication technology , Increasingly popular mobile Internet , The traditional Internet is already migrating to the mobile Internet , Intelligent wearable devices have developed very rapidly in recent years , Become a hot industry , By means of sensors , Information exchange with human body , It is an intelligent device born under the new concept , It has a wide range of applications , And can continuously upgrade according to user needs . Intelligent wearable devices are improving people's quality of life 、 It will play a very important role in promoting intelligent lifestyle .

According to different main functions , Intelligent wearable device products can be divided into the following categories ： Sports and health 、 Somatosensory interaction class 、 Information information 、 Medical health and comprehensive function, etc , Each type of equipment is targeted at different market segments and consumer groups . Sports and medical health equipment include sports 、 Body side wrist strap and smart bracelet , The main consumers are mass consumers ; The devices of somatosensory control and comprehensive functions include smart glasses, etc , The consumer group is mainly young people ; Information consulting devices include smart watches , The main consumers are mass consumers . So far , There are many users of medical and sports health equipment .

With the increasingly fierce competition in the intelligent wearable industry , The phenomenon of homogeneous products is becoming more and more serious , All kinds of intelligent hardware with only a single function have begun to seek cooperation with other intelligent hardware . some time , As the technology of intelligent wearable products in a single field becomes more and more mature , Products in different fields and functional demands will complement each other in function according to the actual needs of users , So as to bring a more intelligent experience that meets the needs of users , The direction of development will be increasingly clear and diversified .

Current adoption STM32 Plus a variety of peripheral sensors with Bluetooth + mobile phone APP Designed a personal health monitoring and management equipment , adopt BLE Low power Bluetooth uploads the collected sensor data to the mobile phone APP Real time display .

2.  Function summary

The main function

（1） Development board selection STM32 Single chip microcomputer does data processing .

（2） Develop a Android mobile phone APP, Used to display data uploaded by Bluetooth

（3） Use Bluetooth to transmit data , Connect the temperature sensor 、 Heart rate pulse sensor 、 The data collected by the acceleration sensor is uploaded to the mobile phone for display .

Generally, the pulse is equal to the heart rate , Blood from the heart flows forward along the walls of the blood vessels , Form a pulse . Normal people, regardless of adults 、 The child 、 aged , Under normal conditions, the pulse and heart rate are consistent . If you have a heart attack , Because the heart's own conduction system has a protective effect , The ventricular rate cannot be the same as the atrial rate , The velocity of conduction in the blood vessels is also different , The pulse will be weak sometimes , Sometimes strong . You may not feel it when it is weak , In this state, the pulse will be less than the heart rate , Heart rate is higher than pulse in atrial fibrillation , So the pulse does not necessarily represent the heart rate .

（4） If the measured body temperature exceeds the warning value , The buzzer on the local device will sound a warning prompt .

Hardware to be used ：

（1）STM32 System board

（2） Temperature sensor

（3） Gyroscope sensor

（4） Heart rate pulse sensor

3.  Hardware selection

3.1 MPU6050 gyroscope

MPU6050 characteristic ：

（1） High performance triaxial acceleration + Six axis sensor module of three-axis gyroscope MPU6050 chip ;

（2） You can use your own digital motion processor (DMP） Hardware acceleration engine , Through the master IKC Interface , Output the data after attitude calculation to the application terminal , Use InvenSense Sports processing database provided by the company , Realize attitude calculation , It reduces the load of motion processing on the operating system and greatly reduces the difficulty of development ;

（3） Small volume , With temperature sensor ;

（4） Support IIC Slave address setting and interrupt ;

（5） compatible 3.3V/5V System ;

3.2 STM32 Development board

3.3  Female to female DuPont line

3.4  Temperature sensor

GY-MCU90615  Is a low-cost infrared temperature module . Working voltage  3-5v  Low power consumption , Small volume . How it works ,  Is to read the infrared temperature data through the single chip microcomputer , A serial port （TTL  level ） Communication mode output . The baud rate of the serial port is  9600bps  And  115200bps  There are two modes: continuous output and query output , Can adapt to different working environments , Connect with all microcontrollers and computers .

Communication protocol
Serial port sends command bytes ：

（1）、 Serial communication parameters （ Default baud rate value 9600 bps, It can be set by software ）
Baud rate ：9600 bps  Check bit ：N  Data bits ：8  Stop bit ：1

Baud rate ：115200 bps  Check bit ：N  Data bits ：8  Stop bit ：1

（2）、 Module input commands , Sent by external controller to GY-MCU90615 modular （ Hexadecimal ）

 1、 Frame head ：0xa5

Command format ： Frame head + Instructions + The checksum (8bit)（ Such as automatically reading the temperature command =0xA5+0x45+0xEA）

2、 Command instruction ： 

Continuous output instruction ：0xA5+0x45+0xEA---------------- Temperature data （ The data type returned by the module is 0x45）

Query output instruction ：

0xA5+0x15+0xBA --------------- Temperature data （ The data type returned by the module is 0x45）

Configuration instructions ：( It takes effect after power failure and restart ) 

Baud rate configuration ：

0xA5+0xAE+0x53 ---------------9600（ Default ）

0xA5+0xAF+0x54 ---------------115200

Whether to automatically send temperature data configuration when powered on ：

0xA5+0x51+0xF6--------------- Automatically output temperature data after power on ( Default )

0xA5+0x52+0xF7--------------- No automatic output of temperature data after power on

 

Communication protocol

A serial port to receive ：

（1）、 Serial communication parameters （ Default baud rate value 9600 bps, It can be set by software ）

  Baud rate ：9600 bps  Check bit ：N  Data bits ：8  Stop bit ：1

Baud rate ：115200 bps  Check bit ：N  Data bits ：8  Stop bit ：1

 

（2）、 Module output format , Each frame contains 9 Bytes （ Hexadecimal ）：

 ①.Byte0: 0x5A  Frame header flag  

 ②.Byte1: 0x5A  Frame header flag  

③.Byte2: 0X45  Data type of this frame （0X45： Temperature data ）

 ④.Byte3: 0x04  Data volume （ following 4 Data 2 Group as an example ）

 ⑤.Byte4: 0x00~0xFF  data 1 high 8 position

 ⑥.Byte5: 0x00~0xFF  data 1 low 8 position

 ⑦.Byte6: 0x00~0xFF  data 2 high 8 position

⑧.Byte7: 0x00~0xFF  data 2 low 8 position

⑨.Byte8: 0x00~0xFF  The checksum （ Previous data accumulation and , Leave only low 8 position ） 

（3）、 Data calculation method

Temperature calculation method  ：

temperature =  high 8 position <<8  low 8 position （ The result is the actual angle multiplied by 100）

  example ： Send instructions ：A5 45 EA , Received a frame of data ：

<5A- 5A- 45- 04- 0C- 78- 0D- 19- A7 >

  Express TO（ A signed 16bit, Indicates the target temperature ）：TO=0x0C78/100=31.92 ℃

  Express TA（ A signed 16bit, Represents the ambient temperature ）：TO=0x0D19/100=33.53 ℃

Usage method
This module outputs data for serial port , After the user connects through the serial port , Send output instructions , for example 0xA5+0x45+0xEA To module , The module will continuously output temperature data ; If you want to query the output, you can send 0xA5+0x15+0xBA To module , Every time it's sent , The module will return temperature data once , The query frequency should be less than 10hz, If higher than 10hz Please use continuous output mode , Send 0xA5+0x45+0xEA Instructions ;


3.5  Pulse sensor

PulseSensor  It is a photoelectric reflective analog sensor for pulse and heart rate measurement . Put it on your fingers 、 Earlobe, etc , Through wire connection, the collected analog signal can be transmitted to  Arduino  And other single chip computers are used to convert into digital signals , Re pass  arduino  After simple calculation by single chip microcomputer, the heart rate value can be obtained , In addition, the pulse waveform can be uploaded to the computer through the serial port to display the waveform . PulseSensor  Is an open source hardware ,  At present, there are corresponding on foreign official websites  arduino  Program and host computer  Processing  Program ,  It is suitable for scientific research and teaching demonstration of heart rate , It is also very suitable for secondary development .

Special reminder ： On the back of the sensor are the electronic components , Please do not touch directly with your fingers ,  In order to avoid static electricity or perspiration causing back device damage .  You can paste black fasteners on the back ,  A transparent film is pasted on the front to protect the sensor .

The interface of the sensor is  3  individual ,  As shown in the red box above .  Please don't speculate by yourself according to the color of the line ,  It should be distinguished according to the identification on the back of the circuit board . The red box  3  Root line , Be marked with  S  Analog signal output line （ Leftmost ） ;  Be marked with + Is the power input line （ middle ）; Be marked with - Is the ground wire （ Far right ） . To sum up ：S →  Pulse signal output （ I want to connect to the MCU  AD  Interface ）

VCC→ 5v( or  3.3v) Power input

GND→ GND  The earth

3.6 PCB Hole board

3.7 BLE Low power Bluetooth module

4.  PC programming

4.1  development environment

The upper computer software adopts Qt framework design ,Qt It's a cross platform C++ GUI application framework .Qt It's a 1991 Year by year Qt Company Cross platform development C++ GUI application development framework . It can develop GUI Program , It can also be used to develop non GUI Program , For example, console tools and servers . Simply speaking ,QT It can easily help you make software with interface , It doesn't even require you to put a lot of energy .

QT Official website :

 

https://www.qt.io/

QT5.12.6 Download address ：

https://download.qt.io/archive/qt/5.12/5.12.6/

Open the download link and select the following version to download ：

qt-opensource-windows-x86-5.12.6.exe 13-Nov-2019 07:28 3.7G Details

Installation of network software is interrupted , Otherwise, you will be prompted to enter the account .

During installation , Check one in the first check box mingw 32 The compiler can , The others are OK by default , Click next to continue the installation .

choice MinGW 32-bit  compiler ：

choice MinGW 32-bit  compiler ：

4.2  Design effect

5. STM32 Development

The following is just a screenshot of the schematic diagram , Running effect , Part of the code , It is difficult to upload the hardware demonstration video , If a complete project is required 、 System schematic diagram 、 Relevant hardware information , You can download it here ：

https://download.csdn.net/download/xiaolong1126626497/85793557

5.1  Hardware wiring

The hardware wiring instructions of this design : 
（1）BLE Low power Bluetooth module
PA2(TX)--RXD  Module receiving pin
PA3(RX)--TXD  Module sending pin
GND---GND  The earth
VCC---VCC  Power Supply （3.3V）

（2） Infrared temperature measurement module
PB10(TX)--RXD  Module receiving pin
PB11(RX)--TXD  Module sending pin
GND---GND  The earth
VCC---VCC  Power Supply （3.3V）

（3）MPU6050 gyroscope
1 VCC 3.3V/5V  Power input  ----> Pick up 3.3V
2 GND  Ground wire  ---> Pick up GND
3 IIC_SDA IIC  Communication data line  -->PB6
4 IIC_SCL IIC  Communication clock line  -->PB7
5 MPU_INT  Interrupt output pin  ----> Unanswered
6 MPU_AD0 IIC  Slave address setting pin --> Unanswered
 AD0 Pin description ：ID=0X68( In the air / Pick up  GND) ID=0X69( Pick up  VCC)
 
 （4） Heart rate detection module
PA1--- Heart rate module DAT Output pin
GND---GND  The earth
VCC---VCC  Power Supply （3.3V）


（--） On board LED The lamp : Low level light
LED1--PC13 
BEEP2--PC14

（--） Onboard keys : 
KEY1--PA0  Press to high level


5.2  Program download

Connect the development board to the computer , Open the program to download the software , Follow the instructions below to download .

5.3  System schematic diagram

5.4 keil engineering

5.5  Function code

#include "stm32f10x.h"
#include "delay.h"
#include "led.h"
#include "key.h"
#include "sys.h"
#include "usart.h"
#include <string.h>
#include <stdlib.h>
#include &quot;timer.h&quot;
#include &quot;adc.h&quot;
#include &quot;mpu6050.h&quot;

/*--------- Heart rate related data values ---------------*/
extern int IBI; // Adjacent beat time
extern int BPM; // Heart rate  
extern int Signal; // Raw signal value  
extern unsigned char QS; // Found heartbeat sign

short aacx,aacy,aacz; // Acceleration sensor raw data
short gyrox,gyroy,gyroz; // Gyroscope raw data
float TO=0; // Infrared temperature measurement - Target temperature
float TA=0; // Infrared temperature measurement - Object temperature
 

// Bluetooth send buffer
u8 BLE_TX_BUFF[100];

/*
The main function :  The entry of program execution
*/
int main(void)
{
 u32 i=0;
 u8 key_val;
 u32 wifi_TimeCnt=0;
 JTAG_Set();
 USART1_Init(115200); // A serial port 1 The initialization
 USART2_Init(9600); // A serial port - bluetooth
 TIMER2_Init(72,20000); // Timeout time 20ms
 USART3_Init(9600); // A serial port - Infrared temperature measurement module
 TIMER3_Init(36,20000); // Timeout time 20ms
 
 // On board button initialization
 KEY_Init();
 // On board LED Lamp initialization
 LED_Init();
 
 //ADC initialization
 ADC_Init(); 
 // Timeout time 2ms 
 TIMER1_Init(72,2000); 
 // initialization MPU6050
 while(MPU6050_Init()) 
 {
 printf(&quot; Three axis accelerometer 、 Gyro initialization failed !\r\n&quot;);
 DelayMs(1000);
 }

 printf(&quot; The system works normally ..\r\n&quot;);
 
 while(1)
 { 
 // Onboard key detection
 key_val=KEY_GetValue();
 if(key_val)
 {
 printf(&quot; Press the key ...\r\n&quot;);
 }
 
 // Time record
 DelayMs(10);
 wifi_TimeCnt++;
 if(wifi_TimeCnt>=100) //1000 One millisecond
 {
 wifi_TimeCnt=0;
 LED1=!LED1;
 MPU6050_Get_Gyroscope(&gyrox,&gyroy,&gyroz); // Get the original data of the gyroscope
 MPU6050_Get_Accelerometer(&aacx,&aacy,&aacz); // Get the acceleration sensor data
 printf(&quot; Three axis gyroscope :x=%d y=%d z=%d\r\n&quot;,gyrox,gyroy,gyroz);
 printf(&quot; Triaxial acceleration :x=%d y=%d z=%d\r\n&quot;,aacx,aacy,aacz);
 printf(&quot;( heart rate )BPM=%d\r\n&quot;,BPM);
 
 // Send data to Bluetooth , Send it to the upper computer
 // for example : update,12,13,14,15,20.5
 // respectively : The acceleration X Axis , The acceleration Y Axis , The acceleration Z Axis , heart rate 、 Temperature
 sprintf((char*)BLE_TX_BUFF,&quot;update,%d,%d,%d,%d,%f&quot;,aacx,aacy,aacz,BPM,TO);
 USARTx_StringSend(USART2,(char*)BLE_TX_BUFF);
 }

 //  Receive the data returned by Bluetooth
 if(USART2_RX_FLAG)
 {
 USART2_RX_BUFFER[USART2_RX_CNT]='\0';
 
 printf(&quot; Bluetooth receives data :\r\n&quot;);
 // The data returned to the serial port print server
 for(i=0;i<USART2_RX_CNT;i++)
 {
 printf(&quot;%c&quot;,USART2_RX_BUFFER[i]);
 }
 USART2_RX_CNT=0;
 USART2_RX_FLAG=0;
 }
 
 // Receive the data received by the infrared temperature measurement module in real time
 if(USART3_RX_FLAG)
 {
 printf(&quot;\r\n Infrared temperature measurement starts :&quot;);
 for(i=0;i<USART3_RX_CNT;i++)
 {
 printf(&quot;%#x &quot;,USART3_RX_BUFFER[i]);
 }
 printf(&quot; End of infrared temperature measurement .\r\n&quot;);
 
 u8 sum=0,i=0;
 for(sum=0,i=0;i<(USART3_RX_BUFFER[3]+4);i++)
 {
 sum+=USART3_RX_BUFFER[i]; 
 }
 
 /*
Temperature calculation method  ：
temperature = high  8  position <<8| low  8  position （ The result is the actual angle multiplied by  100）
example ： Send instructions ： A5 45 EA , Received a frame of data ： <5A- 5A- 45- 04- 0C- 78- 0D- 19- A7 >
Express  TO（ A signed  16bit, Indicates the target temperature ）： TO=0x0C78/100=31.92 ℃
Express  TA（ A signed  16bit, Represents the ambient temperature ）： TO=0x0D19/100=33.53 ℃
 */
 if(sum==USART3_RX_BUFFER[i])// Checksum judgment
 {
 TO=(float)((USART3_RX_BUFFER[4]<<8)|USART3_RX_BUFFER[5])/100.0; // Get the real temperature
 TA=(float)((USART3_RX_BUFFER[6]<<8)|USART3_RX_BUFFER[7])/100.0; // Get the real temperature  
 }
 
 printf(&quot;TO: %f\r\n&quot;,TO);
 printf(&quot;TA: %f\r\n&quot;,TA);
 
 memset(USART3_RX_BUFFER,0,sizeof(USART3_RX_BUFFER));
 USART3_RX_CNT=0;
 USART3_RX_FLAG=0;
 } 
 } 
}