How to send values from the sensor in Arduino

Hi Blynkers I have done weeks of reading and trying but I still can’t get through this. So basically I am sending my sensor data, from Arduino UNO to NodeMCU. Then in NodeMCU, I can show the readings through serial monitor,which shows the transfer is successful. But then I can’t send the same data that the serial monitor in NodeMCU shows to my Blynk app. If I assign the myBPM to any values in NodeMCU coding, I can send it. But I want to send the same myBPM data received from the Arduino, not just any random self-written numbers. Here are the codes:-

(code for Arduino UNO)

#include <SoftwareSerial.h>
#define USE_ARDUINO_INTERRUPTS true    // Set-up low-level interrupts for most acurate BPM math.
#include <PulseSensorPlayground.h>     // Includes the PulseSensorPlayground Library.
#define REC A1 // pin A1 is used for recording
#define recordTime 7000 // recording time 3 seconds

const int PulseWire = 0;       // PulseSensor PURPLE WIRE connected to ANALOG PIN 0
const int LED13 = 13;          // The on-board Arduino LED, close to PIN 13.
int Threshold = 550;
PulseSensorPlayground pulseSensor;
SoftwareSerial BTserial(2, 3); // RX | 

String str;
void setup(){
 Serial.println("Interfacing arduino with nodemcu");
  pulseSensor.blinkOnPulse(LED13);       //auto-magically blink Arduino's LED with heartbeat.
  if (pulseSensor.begin()) {
    Serial.println("We created a pulseSensor Object !");  //This prints one time at Arduino power-up,  or on Arduino reset.  
void loop()
  int myBPM = pulseSensor.getBeatsPerMinute();
  if(pulseSensor.sawStartOfBeat()) {            // Constantly test to see if "a beat happened". 
 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. 

 if(myBPM >= 150){
  Serial.println("WARNING!BPM IS HIGH");                   // dlm if ni ayam  
 if(myBPM >= 150){
  Serial.println("WARNING!BPM IS HIGH");                   // dlm if ni ayam  
  digitalWrite(REC, HIGH);
  digitalWrite(REC, LOW); 

  Serial.println("BPM is constantly HIGH!");



(code for NODEMCU)

#define BLYNK_PRINT Serial

#include <SPI.h>
#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>

// You should get Auth Token in the Blynk App.
// Go to the Project Settings (nut icon).
char auth[] = "19db9b6385ca4c9e818e82f55763787u";
int myBPM;
// Your WiFi credentials.
// Set password to "" for open networks.
char ssid[] = "Phuhu";
char pass[] = "12345678";
BlynkTimer timer;
// This function sends Arduino's up time every second to Virtual Pin (5).
// In the app, Widget's reading frequency should be set to PUSH. This means
// that you define how often to send data to Blynk App.
void myTimerEvent()
  if (Serial.available()) {
  // You can send any value at any time.
  // Please don't send more that 10 values per second.
  Blynk.notify("BPM is HIGH!");

void setup()
  // Debug console
  while (!Serial) {
    ; // wait for serial port to connect. Needed for native USB port only
  Blynk.begin(auth, ssid, pass);
  // You can also specify server:
  //Blynk.begin(auth, ssid, pass, "", 80);
  //Blynk.begin(auth, ssid, pass, IPAddress(192,168,1,100), 8080);
  timer.setInterval(1000L, myTimerEvent);

void loop()

I have done some cross MCU communication via Easy Transfer. Look at what I have tried

1 Like

Oh EasyTransfer. A new library for me. I’ll check it out. Thanks in regard.