Guide Arduino Uno R3 — HID Mouse Emulation via Dual-Board Bridge

[byte_corvus]

Tired of catching bans for simple mouse_event calls? If you are still relying on software-level input for your projects, you are asking for a manual review or an automated flag. Real ones know that hardware-level input is the only way to stay off the radar of modern anti-cheats.

We are looking at a dual-board setup using the Arduino Uno R3. The core of this method relies on the fact that the Uno R3 has two chips: the ATmega328P (logic) and the ATmega16U2 (USB communication). By flashing custom HID firmware onto the 16U2, Windows stops seeing a dev board and starts seeing a legitimate mouse device.

The Hardware Stack

1. HID Arduino: Flashed with mouse firmware on the 16U2. Its 328P forwards reports to the USB controller.
2. Bridge Arduino: Acts as the middleman. It takes commands from your Python script via Serial and sends them to the HID Arduino.

Wiring Logic
Connection is minimal. Connect Pin 3 of the Bridge Arduino to RX Pin 0 of the HID Arduino. Don't forget to share a common GND between both boards or you'll get garbage data.

Step 1: HID Arduino Preparation
Upload this sketch to the board you intend to use as the mouse. This loop waits for 4 bytes of data and pushes them to the USB controller.

struct {
  uint8_t buttons;
  int8_t x;
  int8_t y;
  int8_t wheel;
} mouseReport;

uint8_t nullReport[4] = { 0, 0, 0, 0 };

void setup() {
  Serial.begin(9600);
  delay(200);
}

void loop() {
  if (Serial.available() >= 4) {
    mouseReport.buttons = Serial.read();
    mouseReport.x = Serial.read();
    mouseReport.y = Serial.read();
    mouseReport.wheel = Serial.read();
    Serial.write((uint8_t *)&mouseReport, 4);
    Serial.write((uint8_t *)&nullReport, 4);
  }
}

Step 2: Flashing the 16U2 Firmware
This is where the magic happens. You need to put the 16U2 into DFU mode by shorting the RST and GND pins on the ICSP header near the USB port. Use dfu-programmer to swap the firmware. You can find the necessary Arduino-mouse.hex in the harlequin-tech arduino-usb repository on GitHub.

Spoiler: DFU Commands

dfu-programmer atmega16u2 erase --force
dfu-programmer atmega16u2 flash Arduino-mouse.hex
dfu-programmer atmega16u2 reset

Once you replug, Device Manager should identify it as an HID-compliant mouse.

Step 3: The Serial Bridge
Upload this to your second Arduino. It bridges your PC's Python commands to the HID board via SoftwareSerial.

#include <SoftwareSerial.h>

SoftwareSerial toHID(2, 3); // RX=2, TX=3

void setup() {
  Serial.begin(9600);
  toHID.begin(9600);
}

byte buf[4];
int count = 0;

void loop() {
  while (Serial.available()) {
    buf[count] = Serial.read();
    count++;
    if (count >= 4) {
      toHID.write(buf, 4);
      count = 0;
    }
  }
}

Step 4: Integration
Now you can control your hardware mouse from any script. This is perfect for external aimbots where you don't want any suspicious drivers running on your main rig. Plug the Bridge Arduino into a second PC or laptop for a truly isolated setup.

import serial
import time

ser = serial.Serial('COM21', 9600) # Update with your COM port
time.sleep(2)

def move(x, y):
    x = x & 0xFF
    y = y & 0xFF
    ser.write(bytes([0, x, y, 0]))

def click_left():
    ser.write(bytes([1, 0, 0, 0]))
    time.sleep(0.1)
    ser.write(bytes([0, 0, 0, 0]))

Security Note
While this passes basic HID checks, some kernel-level ACs might flag the specific USB descriptors of the 16U2 if the firmware isn't sufficiently spoofed. If you are hitting high-tier targets, look into changing the VID/PID in the hex before flashing.

Anyone tested this on the latest Vanguard update yet?