RF Remote Sniffer & Replayer

Author: Bocaletto Luca

A turnkey Arduino-based solution to capture (sniff) ASK/OOK 315 MHz or 433 MHz remote‐control codes and replay them on demand. Perfect for testing, reverse‐engineering or automating RF remotes (garage doors, wireless switches, sockets).

Files

• README.md
• RF_Sniffer_Replayer.ino

---

1. Concept

1. Sniff Mode: Arduino listens on a 315 MHz or 433 MHz ASK/OOK receiver and prints any received codes to Serial.
2. Replay Mode: After capturing, you can send the last sniffed code back out via a paired transmitter module by pressing a push-button.

Key features:

• Auto-print raw code and protocol parameters (pulse length, bit count)
• Store the last code in RAM for instant replay
• LED feedback on sniff and transmit events
• Works with fixed-code remotes (rolling-code requires custom logic)

---

2. Bill of Materials

Qty	Component	Notes
1	Arduino Uno / Nano / Pro Mini	5 V version
1	433 MHz ASK Receiver module	e.g. XY-MK-5V
1	433 MHz OOK Transmitter module	e.g. MX-05V
1	Push-button	for manual replay trigger
1	LED (5 mm) + 220 Ω resistor	for status indicator
	Jumper wires & breadboard
	USB cable	for programming & power

---

3. Wiring Diagram

    Arduino        Receiver           Transmitter         Push-Button         LED
    ┌──────────────────────────────────────────────────────────────────────────┐
    │   ┌───┐                                                                  │
    │   D2 ──► DATA_IN     Receiver DATA OUT ─► D3                             │
    │   D3 ◄─ DATA_OUT? [not used]                                             │
    │   5 V ──► VCC         VCC Transmitter VCC ─► 5 V                          │
    │   GND ──► GND         GND Transmitter GND ─► GND                         │
    │                                                                          │
    │   D4 ──► TX_ENABLE (optional)                                            │
    │   D5 ◄─ BUTTON INPUT ── push to GND (with pull-up)                       │
    │   D6 ──► LED (via 220 Ω resistor)                                        │
    └──────────────────────────────────────────────────────────────────────────┘

• DATA_IN pin of receiver → D2
• DATA_OUT pin of transmitter → D4 (some modules need enable; if not, tie VCC)
• Button between D5 and GND; configure internal PULLUP
• LED on D6 through 220 Ω to GND

---

4. Software Setup

1. Install Arduino IDE ≥ 1.8.x.
2. Library: open Library Manager → install rc-switch by sui77.
3. Create a sketch folder named RF_Sniffer_Replayer and place RF_Sniffer_Replayer.ino inside.
4. Open the sketch in the IDE.
5. Select your board (e.g. Uno) and correct COM port.

---

5. Sketch Usage

1. Upload the sketch.
2. Open Serial Monitor at 115200 baud.
3. Set your transmitter frequency (315 or 433) at top of code.
4. Sniff Mode: any RF code received will print as: Received: 12345678 Protocol: 1 PulseLen: 350
5. Replay Mode: press the push-button → Arduino retransmits the last captured code; LED flashes to indicate transmission.

---

6. Notes & Extensions

• To capture rolling-code systems you’ll need to reverse-engineer algorithmic sequence, store dynamic code and state.
• You can adapt this to 315 MHz by changing #define RF_FREQ 315 and wiring a 315 MHz pair.
• Add EEPROM storage to save multiple codes and select via menus.

---

Proceed to the code file below.