Sending Float Data Type from Arduino to ESP32 (NodeMCU) - arduino

Question

I am trying to have a NodeMCU(ESP32) receive a floating data type from an Arduino Uno but I do not have any idea how. Can someone please guide me through the process? For now, I have the basic serial communication code sending a single digit Int from the Arduino to the NodeMCU.
Sender (Arduino Uno):
int val = 1;
void setup()
{
Serial.begin(19200);
}
void loop()
{
Serial.write(val);
delay(3000);
}
Receiver (NodeMCU):
#include <HardwareSerial.h>
HardwareSerial receiver(2);
void setup()
{
receiver.begin(19200, SERIAL_8N1, 16, 17);
Serial.begin(9600);
}
void loop()
{
if(receiver.available() > 0)
{
int received = receiver.read();
Serial.println(received); //tried printing the result to the serial monitor
}
delay(3000);
}

Answer 1

Write/read in the form you use it, is for single bytes only. A float in Arduino consists of 4 bytes.
You can use write to send a series of bytes, and you have to read those bytes, arriving one after the other, depending on the serial speed. Synchronization/lost bytes might be a problem, here in this simple solution I assume the best.
Sender:
float val = 1.234;
void setup() {
Serial.begin(19200);
}
void loop() {
Serial.write((byte*)&val,4);
delay(3000);
}
Receiver:
#include <HardwareSerial.h>
HardwareSerial receiver(2);
void setup()
{
receiver.begin(19200, SERIAL_8N1, 16, 17);
Serial.begin(9600);
}
void loop()
{
if(receiver.available() > 0)
{
delay(5); // wait for all 4 bytes
byte buf[4];
byte* bp = buf;
while (receiver.available()) {
*bp = receiver.read();
if (bp - buf < 3) bp++;
}
float received = * (float*)buf;
Serial.println(received, 3); // printing the result to the serial monitor
}
delay(100); // not really required, should be smaller than sender cycle
}