The goal of this project was to create a heart rate monitor using the Arduino. The issue I have ran into is that my circuit is wired right but random characters are printing out. I am not sure if my pulse sensor is malfunctioning or is it my code. Any suggestions?
#define USE_ARDUINO_INTERRUPTS true //--> Set-up low-level interrupts for most acurate BPM math.
#include <PulseSensorPlayground.h> //--> Includes the PulseSensorPlayground Library.
#include <LiquidCrystal.h> //--> Includes the LiquidCrystal Library.
LiquidCrystal lcd(2, 3, 8, 9, 10, 11); //--> Initialize LiquidCrystal with "lcd". lcd(RS,E,D4,D5,D6,D7).
const int PulseWire = A0; //--> PulseSensor PURPLE WIRE connected to ANALOG PIN 0
const int LED_3 = 13; //--> LED to detect when the heart is beating. The LED is connected to PIN 3 on the Arduino UNO.
int Threshold = 550; //--> Determine which Signal to "count as a beat" and which to ignore.
//----------------------------------------Draw "Heart" on LCD.
/*
heart4 heart5
=== ===
= 00011 11000 00011 11000 = 11 11 11 11
00111 11100 00111 11100 111 111 111 111
01111 11110 01111 11110 1111 1111 1111 1111
11111 11111 11111 11111 11111 11111 11111 11111
heart3 11111 11111 11111 11111 heart6 11111 11111 11111 11111
11111 11111 11111 11111 11111 11111 11111 11111
11111 11111 11111 11111 11111 11111 11111 11111
= 01111 11111 11111 11110 = 1111 11111 11111 1111
------->
= 00011 11111 11111 11000 = 11 11111 11111 11
00001 11111 11111 10000 1 11111 11111 1
00000 11111 11111 00000 11111 11111
heart2 00000 11111 11111 00000 heart7 11111 11111
00000 01111 11110 00000 1111 1111
00000 00111 11100 00000 111 111
00000 00011 11000 00000 11 11
= 00000 00001 10000 00000 = 1 1
=== ===
heart1 heart8
*/
byte heart1[8] = {B11111, B11111, B11111, B11111, B01111, B00111, B00011, B00001};
byte heart2[8] = {B00011, B00001, B00000, B00000, B00000, B00000, B00000, B00000};
byte heart3[8] = {B00011, B00111, B01111, B11111, B11111, B11111, B11111, B01111};
byte heart4[8] = {B11000, B11100, B11110, B11111, B11111, B11111, B11111, B11111};
byte heart5[8] = {B00011, B00111, B01111, B11111, B11111, B11111, B11111, B11111};
byte heart6[8] = {B11000, B11100, B11110, B11111, B11111, B11111, B11111, B11110};
byte heart7[8] = {B11000, B10000, B00000, B00000, B00000, B00000, B00000, B00000};
byte heart8[8] = {B11111, B11111, B11111, B11111, B11110, B11100, B11000, B10000};
//----------------------------------------
int Instructions_view = 500; //--> Variable for waiting time to display instructions on LCD.
PulseSensorPlayground pulseSensor; //--> Creates an instance of the PulseSensorPlayground object called "pulseSensor"
void setup() {
Serial.begin(9600);//--> Set's up Serial Communication at certain speed.
lcd.begin(16, 2); //--> Initializes the interface to the LCD screen, and specifies the dimensions (width and height) of the display
lcd.createChar(1, heart1);
lcd.createChar(2, heart2);
lcd.createChar(3, heart3);
lcd.createChar(4, heart4);
lcd.createChar(5, heart5);
lcd.createChar(6, heart6);
lcd.createChar(7, heart7);
lcd.createChar(8, heart8);
lcd.setCursor(0,0);
lcd.print("Heart Beat/Pulse");
lcd.setCursor(0,1);
lcd.print(" Monitoring EIF ");
delay(2000);
pulseSensor.analogInput(PulseWire);
pulseSensor.blinkOnPulse(LED_3); //--> auto-magically blink Arduino's LED with heartbeat.
pulseSensor.setThreshold(Threshold);
if (pulseSensor.begin()) {
Serial.println("We created a pulseSensor Object !"); //--> This prints one time at Arduino power-up, or on Arduino reset.
}
delay(2000);
lcd.clear();
}
void loop() {
int myBPM = pulseSensor.getBeatsPerMinute(); //--> Calls function on our pulseSensor object that returns BPM as an "int". "myBPM" hold this BPM value now.
if (Instructions_view < 500) {
Instructions_view++;
}
if (Instructions_view > 499) {
lcd.setCursor(0,0);
lcd.print("Put your finger ");
lcd.setCursor(0,1);
lcd.print(" on the sensor please ");
delay(1000);
lcd.clear();
delay(500);
}
if (pulseSensor.sawStartOfBeat()) { //--> If test is "true", then the following conditions will be executed.
Serial.println(" A HeartBeat Detected ! "); //--> Print a message "a heartbeat Detected".
Serial.print("BPM: "); //--> Print phrase "BPM: "
Serial.println(myBPM); //--> Print the value inside of myBPM.
lcd.setCursor(1,1);
lcd.write(byte(1));
lcd.setCursor(0,1);
lcd.write(byte(2));
lcd.setCursor(0,0);
lcd.write(byte(3));
lcd.setCursor(1,0);
lcd.write(byte(4));
lcd.setCursor(2,0);
lcd.write(byte(5));
lcd.setCursor(3,0);
lcd.write(byte(6));
lcd.setCursor(3,1);
lcd.write(byte(7));
lcd.setCursor(2,1);
lcd.write(byte(8));
lcd.setCursor(5,0);
lcd.print("Heart Rate");
lcd.setCursor(5,1);
lcd.print(": ");
lcd.print(myBPM);
lcd.print(" ");
lcd.print("BPM ");
Instructions_view = 0;
}
delay(20);// End of code
}
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1 Like
Welcome back @hoodjoi. Thread moved as requested.
I see quite a few prints that would be useful for debugging. I suggest capturing the output from serial monitor then posting that output here.
Perhaps you are using the wrong LCD library. There are several with the same or very similar names.
Since the problem seems to be with the LCD, first make sure that the basic LCD "Hello World" example runs as expected.
as @jremington says, getting LCDs to work can be a pain.
You ARE getting characters on the display so so far so good.
Can you provide a link to the ACTUAL LCD DISPLAY you are using, and also to the Library you are using?
I bought my 16x2 LCD Display directly from Arduino `
#include <PulseSensorPlayground.h> //--> Includes the PulseSensorPlayground Library.
#include <LiquidCrystal.h> //--> Includes the LiquidCrystal Library.
You might try simplifying the code, down to the essentials. All this does is to write custom characters representing a heartbeat, and can be removed.
lcd.setCursor(1,1);
lcd.write(byte(1));
lcd.setCursor(0,1);
lcd.write(byte(2));
lcd.setCursor(0,0);
lcd.write(byte(3));
lcd.setCursor(1,0);
lcd.write(byte(4));
lcd.setCursor(2,0);
lcd.write(byte(5));
lcd.setCursor(3,0);
lcd.write(byte(6));
lcd.setCursor(3,1);
lcd.write(byte(7));
lcd.setCursor(2,1);
lcd.write(byte(8));
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I can see that you've initialized the serial monitor but not printing anything there. Try to print the values in the serial monitor by adding some lines to your code. And see if you get the proper result there.
Can you show us the "hello World" code please?
Often its better to develop code that is working, rather than to expect someone else's project code to work on your equipment.
As @jremington says, a lot of the code is unnecessary and likely obscuring the real problem.
#include <LiquidCrystal.h> // Library for the LCD Display
// that is lcd(RS,E,D4,D5,D6,D7); 4 bits mode
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
void setup()
{
// set up the LCD's number of columns and rows:
lcd.begin(16, 2); // init the HD4470 chip of the LCD
// Print a message to the LCD.
lcd.print("Hello World"); // print from position 0 to position 12 - ASCII code being printed
// into the memory of the LCD display IC.
}
void loop()
{
// Just do nothing in here
lcd.setCursor(0,1); // Start the cursor at line 0, position 0
lcd.print(millis()/1000);
}
why are they different?
I didn't notice it was different. The hello world one was a sample code from the Arduino IDE and the other was from another person's code
The LCD wiring needs to be completely different for the two code examples. Did you change the wiring?
Triple check that the wiring for your non-working code agrees with the pin assignments in the code. Every single connection must be correct!
I sure have. My college professor check for me last week and confirmed its correct. Just the wrong print out
.. and one works and the other doesn't. Could that be the reason?
Very much a understandable assumption. I am building a heart rate monitor and found code to work the thing. So modeled my project after that person's as a prototype.
This is the project i was referencing
https://create.arduino.cc/projecthub/mohammadsohail0008/heart-beat-monitoring-device-8adf7c