Failure Serial Communication between C# Winform and Uno R4 wifi

Official Hardware UNO Family UNO R4 WiFi
1

Winform that I made can't receive datas from Arduino Uno R4 wifi. It works well when I used Arduino Nano.

This is arduino sketch :

#include<stdio.h>

char inp[10];


void setup() {
 Serial.begin(115200);
}

void loop() {

  if (Serial.available()>0) {
    int i = 0;
    //inp = Serial.read();
    for (i=0; i<10; i++) {
      inp[i] = Serial.read();

      delayMicroseconds(80);
    }
    if (inp[0] == 'S') {
      Serial.println("Hello");
    }
  }
}

and below is for winform :

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO.Ports;

namespace _230801_test2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            serialPort1.Open();
        }


        private void button2_Click(object sender, EventArgs e)
        {
            serialPort1.Write("S");
            Debug.WriteLine("S");

            string data = serialPort1.ReadLine();
            Debug.WriteLine(data);
            richTextBox1.Text += data;
        }
    }
}
2

Welcome to the forum

Why did you start a topic in the Uncategorised category of the forum when its description is

:warning: DO NOT CREATE TOPICS IN THIS CATEGORY :warning:

Your topic has been moved to the Uno R4 category

3

i have the exact same problem, did you manage to find a sollution?,
it works with an arduino r3??