Comprendre un programme arduino
Bonsoir, j'ai commandé un capteur cardiaque dont j'ai pu m'approprier le programme suivant afin d'utiliser ce capteur avec l'arduino, le soucis étant que j'aimerais comprendre les tâches réalisés et surtout les intervalles de temps de prise de mesure sauf que je ne connais rien à ce langage. Pouvez-vous m'expliquer ce qu'il se passe dans ce programme, s'il-vous-plait ?
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| // Function: This program can be used to measure heart rate, the lowest pulse in the program be set to 30.
// Use an external interrupt to measure it.
// Hardware: Grove - Ear-clip Heart Rate Sensor, Grove - Base Shield, Grove - LED
// Arduino IDE: Arduino-1.0
// Author: FrankieChu
// Date: Jan 22, 2013
// Version: v1.0
// by <a href="http://www.seeedstudio.com" target="_blank">www.seeedstudio.com</a>
#define LED 4//indicator, Grove - LED is connected with D4 of Arduino
boolean led_state = LOW;//state of LED, each time an external interrupt
//will change the state of LED
unsigned char counter;
unsigned long temp[21];
unsigned long sub;
bool data_effect=true;
unsigned int heart_rate;//the measurement result of heart rate
const int max_heartpluse_duty = 2000;//you can change it follow your system's request.
//2000 meams 2 seconds. System return error
//if the duty overtrip 2 second.
void setup()
{
pinMode(LED, OUTPUT);
Serial.begin(9600);
Serial.println("Please ready your chest belt.");
delay(5000);
arrayInit();
Serial.println("Heart rate test begin.");
attachInterrupt(0, interrupt, RISING);//set interrupt 0,digital port 2
}
void loop()
{
digitalWrite(LED, led_state);//Update the state of the indicator
}
/*Function: calculate the heart rate*/
void sum()
{
if(data_effect)
{
heart_rate=1200000/(temp[20]-temp[0]);//60*20*1000/20_total_time
Serial.print("Heart_rate_is:\t");
Serial.println(heart_rate);
}
data_effect=1;//sign bit
}
/*Function: Interrupt service routine.Get the sigal from the external interrupt*/
void interrupt()
{
temp[counter]=millis();
Serial.println(counter,DEC);
Serial.println(temp[counter]);
switch(counter)
{
case 0:
sub=temp[counter]-temp[20];
Serial.println(sub);
break;
default:
sub=temp[counter]-temp[counter-1];
Serial.println(sub);
break;
}
if(sub>max_heartpluse_duty)//set 2 seconds as max heart pluse duty
{
data_effect=0;//sign bit
counter=0;
Serial.println("Heart rate measure error,test will restart!" );
arrayInit();
}
if (counter==20&&data_effect)
{
counter=0;
sum();
}
else if(counter!=20&&data_effect)
counter++;
else
{
counter=0;
data_effect=1;
}
}
/*Function: Initialization for the array(temp)*/
void arrayInit()
{
for(unsigned char i=0;i < 20;i ++)
{
temp[i]=0;
}
temp[20]=millis();
} |
