提前感谢社区的帮助。
截至目前，我们希望获得一致的数据输出到串行监视器。
我们看到打开设备几秒后输出到显示器，有时输出超过15秒。此外，我们得到的氧浓度值远高于100％。
有时我们得到一个HR值，而O2值似乎是合理的，但是，情况并非总是如此，而且相当不一致。
中断的时间或我们写入串行监视器的频率是否有问题？
代码如下：
#include <LiquidCrystal.h> //Including this so we can test the code as is
//We can always remove the LCD code later
#include "floatToString.h" //SEE COMMENTS BELOW
/*
* You need to include the float to string header file. I am unsure if this goes in the
* main direcotry withe the code or just the library. For completness I have incouded it on my
* computer in both locations. Please do the same untill we can test further.
*/
#include "Arduino.h" //Formally floatToString.h This changed years ago, using Arduino.h
#include <SoftwareSerial.h> //bluetooth
#include <TimerOne.h> //interrupts SEE COMMENT BELOW
//**********************************************************
//Read Below..........................................
/*
* Need a library for the above timeerOne file
* without the library, you will get an error.
* See Github at https://github.com/PaulStoffregen/TimerOne
* Download the timerOne-master.zip file and place the entire
* TimerOne-master folder in my Documents > Arduino > libraries
*/
//**********************************************************
#define analogPin A0
#define Theta 0.6
#define RxD 1 //bluetooth read
#define TxD 0 //bluetooth transmit
#define DEBUG_ENABLED //bluetooth
#define redLED 5 //High is Red led on, Low is Infrared on.
//#define iredLED 6
volatile int maxTemp,minTemp; //shared variables between interrupts and loop
volatile int lastcount,count;
int Rmax, Rmin, IRmax, IRmin;
float R, Spo2,HeartR_frq;
int Sp02_int;
int HeartRate, HeartR;
float LastHeartRate = 70; //default
int average = 140; //average is average crossing
//int average2 = 220;
int interrupts_counter =0; //count the times of interrupts
float value=0.5;
float Spo2_float;
char buffer[25];
SoftwareSerial blueToothSerial(RxD,TxD); //define bluetooth
void setup() {
pinMode(redLED, OUTPUT); //define LED
pinMode(RxD, INPUT); //bluetooth input
pinMode(TxD, OUTPUT); //bluetooth output
pinMode(analogPin, INPUT); //analog signal input
//initially switch on Red LED, after each interrupt will turn on the other
digitalWrite(redLED, HIGH);
Serial.begin(115200);
//bluetooth
setupBlueToothConnection();
//We might not need this, this might be for the LCD display. Leaving it in for now
init_interrupts();
Timer1.initialize(40000); //terrupt every 0.04 seconds
Timer1.attachInterrupt(max_min_num); //interrupt call max_min_num function
Rmax = 0;
IRmax = 0;
Rmin = 0;
IRmin = 0;
LastHeartRate = 70;
}
void loop() {
//initialize LCD
LiquidCrystal lcd(8, 9, 4, 5, 6, 7); // initialize LCD, the pins are all depends
lcd.begin(8, 2); //set up the LCD's number of columns and rows:
while(1){ //the whole while is used to avoid LCD reinitialize
digitalWrite(redLED,HIGH);
delay(2000); //let red led signal to be stable
//interrupts();
while(!((lastcount>average )&& (count<average)) ){ }
digitalWrite(redLED,HIGH);
init_interrupts();
while(!((lastcount>average )&& (count<average)) ){ }
noInterrupts(); // temporarily disabel interrupts, to be sure it will not change while we are reading
Rmax = maxTemp;
Rmin = minTemp;
delay(100);
HeartR_frq = 1/(0.04*interrupts_counter); //d is the times of ISR in 1 second,
interrupts(); //enable interrupts
HeartRate = HeartR_frq * 60;
if(HeartRate> 60 && HeartRate< 120){
HeartR = Theta*HeartRate + (1 - Theta)*LastHeartRate; //Use theta to smooth
LastHeartRate = HeartR;
}
digitalWrite(redLED, LOW);
//initialize lcd
lcd.setCursor(0,0);
lcd.print("HR:");
lcd.setCursor(5,0);
lcd.print(HeartR);
R = (Rmax - Rmin);
Spo2 = (R-180)*0.01 +97.838;
int Spo2_int = (int)Spo2; //float Spo2 to int Spo2_int
String Spo2_float = floatToString(buffer,Spo2,2);
lcd.setCursor(0,1);
lcd.print("SPO2:");
lcd.setCursor(5,1);
lcd.print(Spo2_int);
//transmit data to phone app through bluetooth
String H = String("H: ")+HeartR +String("S: ") +Spo2_float;
Serial.println(H);
delay(1000);
init_interrupts();
}
}
void setupBlueToothConnection() //initialize bluetooth
{
blueToothSerial.begin(115200); //Set BluetoothBee BaudRate to default baud rate 38400
blueToothSerial.print("\r\n+STWMOD=0\r\n"); //t the bluetooth work in slave mode
blueToothSerial.print("\r\n+STNA=HC-06\r\n"); //t the bluetooth name as "HC-05"
blueToothSerial.print("\r\n+STOAUT=1\r\n"); // Permit Paired device to connect me
blueToothSerial.print("\r\n+STAUTO=0\r\n"); // Auto-connection should be forbidden here
delay(2000); // This delay is required.
//blueToothSerial.print("\r\n+INQ=1\r\n"); //make the slave bluetooth inquirable
blueToothSerial.print("bluetooth connected!\n");
delay(2000); // This delay is required.
blueToothSerial.flush();
}
void init_interrupts()
{
maxTemp = 0;
minTemp = 1023;
count = 0;
lastcount =0;
interrupts_counter = 0;
}
void max_min_num()
{
lastcount = count;
count = analogRead(analogPin); //read signa
if(count> maxTemp){
maxTemp = count;
}
else if(count<minTemp){
minTemp = count;
}
interrupts_counter++; //interrupt counter
}
提前感谢您的时间！