# Grove Ear clip Heart Rate Sensor ![](https://raw.githubusercontent.com/SeeedDocument/Grove-Ear-clip_Heart_Rate_Sensor/master/img/Heart_rate_ear_clip_kit.jpg) The Heart Rate Ear clip kit contains a ear clip and a receiver module. The heart rate measure kit can be used to monitor heart rate of patient and athlete. The result can be displayed on a screen via the serial port and can be saved for analysis. The entire system is a high sensitivity, low power consumption and portable. [![](https://raw.githubusercontent.com/SeeedDocument/common/master/Get_One_Now_Banner.png)](http://www.seeedstudio.com/Grove-Ear-clip-Heart-Rate-Sensor-p-1116.html) ## Features * Low power consumption * Convenient to use * High sensitivity * Fully RoHS compliant !!!Tip More details about Grove modules please refer to [Grove System](http://wiki.seeed.cc/Grove_System/) ## Specifications | Item | Min | Typical | Max | Unit | | ----------------------- | ------- | ------- | ---- | ---- | | Voltage | 3.0 | 5.0 | 5.25 | V | | Work Current | 6.5 | mA | | | | Length of ear clip wire | 120 | cm | | | | Measures Range | ≥30/min | - | | | ## Application Ideas * Heart rate monitor. ## Platforms Supported ## Usage The following sketch demonstrates a simple application of using the Ear-clip Heart Rate Sensor to measure heart rate. * Connect this module to the digital port D2 on [Grove-Base shield](http://www.seeedstudio.com/depot/grove-base-shield-p-754.html?cPath=132). And connect Grove-LED to Digital port 4. * Plug the Base Shield into Arduino/Seeeduino. ![](https://raw.githubusercontent.com/SeeedDocument/Grove-Ear-clip_Heart_Rate_Sensor/master/img/Ear_Clip_Heart_Rate.jpg) * Copy and paste code below to a new Arduino sketch. ``` // 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 www.seeedstudio.com #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(); } ``` * Upload the code. * Make sure the sensor contacts your ear skin. This is the signal when we are measuring the heart rate: ![](https://raw.githubusercontent.com/SeeedDocument/Grove-Ear-clip_Heart_Rate_Sensor/master/img/GROVE_heart_rate_chest_belt.bmp) ![](https://raw.githubusercontent.com/SeeedDocument/Grove-Ear-clip_Heart_Rate_Sensor/master/img/Grove-heart_rate_serial.jpg) In the first of the figures, which is a waveform diagram of the detected heartbeat, a high pulse comes when beating. Note If the serial monitor return an error message, please change the position of the sensor. ## Resources * [Grove - Ear-clip Heart Rate Sensor Demo code](https://raw.githubusercontent.com/SeeedDocument/Grove-Ear-clip_Heart_Rate_Sensor/master/res/Grove-Heart_rate_chest_belt_V1.0.zip) --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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