Joy-it SEN-KY039HS Manual 

2 3 SEN-KY039HS TABLE OF CONTENT 1. Introduction 2. Use with the Raspberry Pi 2.1 Connection 2.2 Installation 2.3 Program example 3. Use with Arduino 3.1 Connection 3.2 Program example 4. Further information 5. Support

3 3 SEN-KY039HS 1. Introduction Dear customer, Thank you for choosing our product. In the following, we will show you what to consider during commissioning and use. If you experience any unexpected problems during use, you are welcome to contact us.

4 3 SEN-KY039HS 2. Use with the Raspberry Pi 2.1 Connection Since the heartbeat sensor is an analog sensor and the Raspberry Pi has no analog inputs, you will need to use an analog-to-digital converter. For example our ADC COM-KY053ADC. Raspberry Pi KY039HS ADC 3v3 (Pin1) VDD GND (Pin 6) GND SCL (Pin 5) SCL SDA (Pin 3) SDA Black A0 GND (Pin 14) Grey 3v3 (Pin 17) White

5 3 SEN-KY039HS 2.2 Installation First, you need to install the library for the analog-to-digital converter. This was published under the following link under the MIT license. To install the library, simply enter the following command in the console: In addition, you must enable I2C on your Raspberry Pi by entering the following command: Now go to Interfacing Options -> and activate I2C. 2.3 Program example sudo raspi-config sudo pip3 install adafruit-circuitpython-ads1x15 import time import board import busio import adafruit_ads1x15.ads1115 as ADS from adafruit_ads1x15.analog_in import AnalogIn # Create the I2C bus i2c = busio.I2C(board.SCL, board.SDA) # Create the ADC object using the I2C bus ads = ADS.ADS1115(i2c) # Create single-ended input on channels chan0 = AnalogIn(ads, ADS.P0) chan1 = AnalogIn(ads, ADS.P1) chan2 = AnalogIn(ads, ADS.P2) chan3 = AnalogIn(ads, ADS.P3) if __name__ == '__main__': # initialization GAIN = 2/3 curState = 0 thresh = 525 # mid point in the waveform P = 512 T = 512 stateChanged = 0 sampleCounter = 0 lastBeatTime = 0 firstBeat = True secondBeat = False Pulse = False

6 3 SEN-KY039HS 2.3 Program example IBI = 600 rate = [0]*10 amp = 100 lastTime = int(time.time()*1000) # Main loop. use Ctrl-c to stop the code while True: # read from the ADC Signal = chan0.value #TODO: Select the correct ADC channel curTime = int(time.time()*1000) sampleCounter += curTime - lastTime; # keep track of time in mS with this variable lastTime = curTime N = sampleCounter - lastBeatTime; # monitor the time since last beat to avoid noise ## find the peak if Signal < thresh and N > (IBI/5.0)*3.0 : # wait 3/5 of last IBI if Signal < T : # T is the trough T = Signal; # keep track of lowest point in pulse wave if Signal > thresh and Signal > P: # thresh condition helps avoid noise P = Signal; # P is the peak # keep track of highest point in pulse wave # signal surges up in value every time there is a pulse if N > 250 : # avoid high frequency noise if (Signal > thresh) and (Pulse == False) and (N > (IBI/5.0)*3.0) : Pulse = True; # set the Pulse flag when we think there is a pulse IBI = sampleCounter - lastBeatTime; # measure time between beats in mS lastBeatTime = sampleCounter; # keep track of time for next pulse if secondBeat : # if this is the second beat, if secondBeat == TRUE secondBeat = False; # clear secondBeat flag for i in range(0,10): rate[i] = IBI; if firstBeat : firstBeat = False; secondBeat = True; continue # keep a running total of the last 10 IBI values runningTotal = 0; # clear the runningTotal variable for i in range(0,9): # shift data in the rate array rate[i] = rate[i+1]; runningTotal += rate[i];

7 3 SEN-KY039HS 2.3 Program example 3. Use with the Arduino 3.1 Connection rate[9] = IBI; runningTotal += rate[9]; runningTotal /= 10; BPM = 60000/runningTotal; print ('BPM: {}'.format(BPM)) if Signal < thresh and Pulse == True : # when the values are going down, the beat is over Pulse = False; amp = P - T; thresh = amp/2 + T; P = thresh; T = thresh; if N > 2500 : # if 2.5 seconds go by without a beat thresh = 512; # set thresh default P = 512; # set P default T = 512; # set T default lastBeatTime = sampleCounter; # bring the lastBeatTime up to date firstBeat = True; # set these to avoid noise secondBeat = False; # when we get the heartbeat back print ("no beats found") time.sleep(0.005) Arduino KY039HS 5V White GND Grey A0 Black

8 3 SEN-KY039HS 3.2 Program example //////////////////////////////////////////////////////////////////////// /// Copyright (c)2015 Dan Truong /// Permission is granted to use this software under the MIT /// licence, with my name and copyright kept in source code /// http://http://opensource.org/licenses/MIT /// /// KY039 Arduino Heartrate Monitor V1.0 (April 02, 2015) //////////////////////////////////////////////////////////////////////// // German Comments by Joy-IT int rawValue; bool heartbeatDetected(int IRSensorPin, int delay) { static int maxValue = 0; static bool isPeak = false; bool result = false; rawValue = analogRead(IRSensorPin); // Hier wird der aktuelle Spannungswert am Fototransistor ausgelesen und in der rawValue- Variable zwischengespeichert rawValue *= (1000/delay); // Sollte der aktuelle Wert vom letzten maximalen Wert zu weit abweichen // (z.B. da der Finger neu aufgesetzt oder weggenommen wurde) // So wird der MaxValue resetiert, um eine neue Basis zu erhalten. if (rawValue * 4L < maxValue) { maxValue = rawValue * 0.8; } // Detect new peak if (rawValue > maxValue - (1000/delay)) { // Hier wird der eigentliche Peak detektiert. Sollte ein neuer RawValue groeßer sein // als der letzte maximale Wert, so wird das als Spitze der aufgezeichnten Daten er- kannt. if (rawValue > maxValue) { maxValue = rawValue; } // Zum erkannten Peak soll nur ein Herzschlag zugewiesen werden if (isPeak == false) { result = true; } isPeak = true; } else if (rawValue < maxValue - (3000/delay)) { isPeak = false; // Hierbei wird der maximale Wert bei jeden Durchlauf // etwas wieder herabgesetzt. Dies hat den Grund, dass // nicht nur der Wert sonst immer stabil bei jedem Schlag // gleich oder kleiner werden wuerde, sondern auch, // falls der Finger sich minimal bewegen sollte und somit // das Signal generell schwaecher werden wuerde. maxValue-=(1000/delay); } return result; }

9 3 SEN-KY039HS int ledPin=13; int analogPin=0; void setup() { // Die eingebaute Arduino LED (Digital 13), wird hier zur Ausgabe genutzt pinMode(ledPin,OUTPUT); // Serielle Ausgabe Initialisierung Serial.begin(9600); Serial.println("Heartbeat Detektion Beispielcode."); } const int delayMsec = 60; // 100msec per sample // Das Hauptprogramm hat zwei Aufgaben: // - Wird ein Herzschlag erkannt, so blinkt die LED kurz aufgesetzt // - Der Puls wird errechnet und auf der serriellen Ausgabe ausgegeben. void loop() { static int beatMsec = 0; int heartRateBPM = 0; if (heartbeatDetected(analogPin, delayMsec)) { heartRateBPM = 60000 / beatMsec; // LED-Ausgabe bei Herzschlag digitalWrite(ledPin,1); // Serielle Datenausgabe Serial.print("Puls erkannt: "); Serial.println(heartRateBPM); beatMsec = 0; } else { digitalWrite(ledPin,0); } delay(delayMsec); beatMsec += delayMsec; }

10 3 SEN-KY039HS Our information and take-back obligations according to the ElektroG Symbol on electrical and electronic equipment This crossed-out dustbin means that electrical and electronic equipment does not belong in the household waste. You must return the old appliances to a collection point. Before handing over waste batteries and accumulators that are not enclosed by waste equipment must be separated from it. Return options As an end user, you can return your old appliance (which essentially fulfils the same function as the new appliance purchased from us) free of charge for disposal when you purchase a new appliance. Small appliances with no external dimensions greater than 25 cm can be disposed of in normal household quantities independently of the purchase of a new appliance. Possibility of return at our company location during opening hours Simac GmbH, Pascalstr. 8, D-47506 Neukirchen-Vluyn Possibility of return in your area We will send you a parcel stamp with which you can return the device to us free of charge. Please contact us by e-mail at [email protected] or by telephone. Information on packaging If you do not have suitable packaging material or do not wish to use your own, please contact us and we will send you suitable packaging. 4. Further Information

11 3 SEN-KY039HS 5. Support We are also there for you after your purchase. If any questions remain open or problems arise, we are also available by e-mail, telephone and ticket support system. E-Mail: [email protected] Ticket-System: http://support.joy-it.net Phone: +49 (0)2845 98469 – 66 (10- 17 o‘clock) For more information visit our website: www.joy-it.net