Hi, I am hoping someone can help me with an issue I am having. I am trying to configure a heart rate sensor from pulsesensor.com. I am using an Adruino Mega. I have downloaded the example sketch, and I have also coded up the entire sketch myself - the Mega's setup method keeps being called repeatedly whenever I run the .begin() method.
I am using Serial on baud 115200 (as per the instructions).
Here is my code
#define USE_ARDUINO_INTERRUPTS true
const int pulseWire = A1;
const int led = 7;
int threshold = 440;
PulseSensorPlayground pulseSensor;
void setup()
{
Serial.begin(115200);
pulseSensor.analogInput(pulseWire);
pulseSensor.blinkOnPulse(led);
pulseSensor.setThreshold(threshold);
pulseSensor.setSerial(Serial);
Serial.println("Hi");
pulseSensor.begin();
}
void loop() {
if (pulseSensor.sawStartOfBeat()) { // Constantly test to see if "a beat happened".
int myBPM = pulseSensor.getBeatsPerMinute(); // Calls function on our pulseSensor object that returns BPM as an "int".
// "myBPM" hold this BPM value now.
Serial.println("♥ A HeartBeat Happened ! "); // If test is "true", print a message "a heartbeat happened".
Serial.print("BPM: "); // Print phrase "BPM: "
Serial.println(myBPM); // Print the value inside of myBPM.
}
}
I have made sure that I am using the latest version of the pulse sensor playground library, I have looked at all the GitHub examples, no luck
I added the text output "Hi" above the method call to be sure that it is what is causing the board to maybe restart the MCU. I have a looong list of Hi messages. I am a PhD student, in Computer Science, not electronics and I really need to finish this project. Any and all help is appreciated. I am also new and not an expert, so apologies if I broke any rules or posted anything in the wrong format.
Thank you
Sarina
As I understand it computer science deals with the theory of computer processes, while computer programming is the practical application that brings those ideas to life. In this case a lack of electronics should not be a problem.
I suggest you use there code to be sure the hardware is working first.
Thank you so much for your reply. I have used the example sketch , same problem. I have tried in two different Arduino Megas Ans with three different sensors, I still have the same issue.
Have you tried it with the processor they used ie the UNO? There are some differences between them. Since this is a learning experience post a simple schematic showing how it is wired.
The sensor works fine on an Uno - however I need to use a Mega because I need the I/O ports. Is there anything I should be doing differently. Thank you again for your help. I am not sure how to draw an electric diagram, but is literally just the sensor connected to A0, GND and 5V VCC.
Once again thank you for all the help!
Hi , thank you so much for replying. My sincere apologies, I have updated the script and not my diagram - I have tried A0, A1, A2 (thought maybe a pin was fried ). So that is not the cause. Apologies for the confusion.
Sarina
THANK YOU for your reply, I was afraid that I was losing my mind. I ended up stepping back the library to 1.7x and it is now reading a heartbeat, but unfortunately is only returning heart attack-type returns , like 232.
There are many varieties of port ex panders available, some in the $1.50 range US. They are easy to use, I do not use any of the libraries except maybe the wire library sometimes. PCF8574 is common for 8 bit and PCF8575 for 16 bit expansions. They connect to the I2C buss so you need +5, Ground, SCL and SDA connections. All of them go to the same four pins on the Arduino IE it is a bus.
Thank you so much for your recommendation, I did not know about these, I will absolutely get some. I am too far into this project to move controllers now ( I think ) it is the last stretch to deploying my PhD artefact and writing up my thesis. Maybe that heart reading is correct (just kidding) . I truly appreciate the support and advice
