Receiving no data from serial connectionc

Board: ESP32-EVB

I am trying to read data from a Radar's RS232 Interface through the UEXT connector on the ESP.

As per the schematics, I am using GPIO 36 as the rxPin and GPIO 4 as the txPin.

HardwareSerial USE_SERIAL1(1);

#define RX1 36
#define TX1 4

void setup() {
  USE_SERIAL1.begin(9600, SERIAL_8N1, RX1, TX1);

void loop() {
  // Check if we are receiving data
  if(USE_SERIAL1.available() >0) {
    Serial.println("USE_SERIAL1 is available.");
    while (USE_SERIAL1.available()) {
      char c = char(;
      Radar_String += c;
    Serial.println("Radar_String = " + Radar_String);

The radar is set up to send data on 9600.

I'm receiving no data. Not even Serial.println("Serial2 is available.");.

Any thoughts ?

Hi there.

That behavior is obvious because you have set your radar to buad rate of '9600'.

But in code you have mentioned


rather the correct one should be


The baud rate should match in order to do serial communication.