InfraFi

Transmit WiFi credentials from a Flipper Zero to a Linux server using infrared. Point, press Send, connected.

Built for headless servers (NAS boxes, Intel NUCs, etc.) where typing WiFi passwords is painful or impossible.

How It Works

flowchart LR
    subgraph Flipper Zero
        A[InfraFi App]
        A1[Manual Entry]
        A2[NFC Tag Scan]
        A3[Saved Networks]
        A1 --> A
        A2 --> A
        A3 --> A
    end

    subgraph Linux Server
        B[infrafid daemon]
        B1["IR RX (/dev/lirc0)"]
        B2[WiFi Connect]
        B3["IR TX (ACK)"]
        B1 --> B --> B2
        B -.-> B3
    end

    A -- "IR (RC-6, 36kHz)" --> B1
    B3 -. "ACK (OK/FAIL)" .-> A

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The Flipper encodes WiFi credentials as a sequence of RC-6 IR messages and blasts them at the server's CIR (Consumer IR) receiver. The infrafid daemon decodes the transmission and connects to the network automatically. No pairing, no Bluetooth, no network required — just line-of-sight IR.

With ACK enabled, the daemon transmits a response back via IR — the Flipper displays whether the connection succeeded (with IP address) or failed.

Features

Flipper Zero App

• Manual entry — On-screen keyboard for SSID and password, security type selector (Open/WPA/WEP/SAE)
• NFC WiFi tags — Scan an NTAG213/215/216 tag with WiFi credentials (standard NDEF WiFi Simple Configuration format) and transmit instantly
• Saved networks — Credentials auto-save to SD card after successful transmit. Browse, resend, or delete saved networks
• Fast transmission — Full credentials sent in under a second via RC-6 protocol
• Hidden network support — Toggle hidden SSID flag
• ACK feedback — Optional. When enabled in Settings, the Flipper waits for a response from the server after sending credentials. Shows "Connected! IP: x.x.x.x" or "Failed" on screen

Linux Daemon (infrafid)

• Zero dependencies — Pure C, no Python or runtime libraries needed
• Automatic WiFi connection — Detects NetworkManager, systemd-networkd, or ifupdown and connects appropriately
• Rollback on failure — Saves current SSID before connecting; reconnects to previous network if the new one fails
• SSID verification — After WPA handshake completes, verifies the connected SSID matches the target to avoid false positives
• IR ACK response — Sends connection result back to the Flipper via IR (requires TX hardware or external IR blaster)
• Runs as a service — systemd unit with auto-restart, logs to journald/syslog
• ITE8708 optimized — Uses LIRC_MODE_SCANCODE for kernel-decoded RC-6, avoiding hardware FIFO overflow issues with the CIR receivers found in Intel NUCs

Getting Started

Requirements

Flipper Zero:

• Flipper Zero with up-to-date firmware
• ufbt (Flipper build tool)

Linux Server:

• IR receiver (tested with ITE8708 CIR in Intel NUCs)
• /dev/lirc0 device available
• gcc and Linux headers for building
• NetworkManager, systemd-networkd, or ifupdown + wpa_supplicant for WiFi management

Build & Install — Flipper App

# Clone the repo
git clone https://github.com/amd989/infrafi.git
cd infrafi

# Build
ufbt

# Deploy to Flipper (connected via USB)
ufbt launch

Build & Install — Linux Daemon

cd daemon

# Quick install (builds, installs, configures RC-6, starts service)
sudo ./install.sh

# Or manually:
make
sudo make install
sudo systemctl enable --now infrafid

The install script automatically:

• Configures the IR receiver for RC-6 protocol only
• Creates a udev rule so the config persists across reboots
• Installs and starts the systemd service

Pre-built Packages

Debian/Ubuntu and RPM packages are available from GitHub Releases for amd64, arm64, and armhf architectures.

APT repository:

curl -fsSL https://amd989.github.io/InfraFi/install-apt.sh | sudo bash
sudo apt install infrafid

YUM repository:

curl -fsSL https://amd989.github.io/InfraFi/install-yum.sh | sudo bash
sudo yum install infrafid

Verify IR Receiver

# Check that rc-6 is the active protocol
cat /sys/class/rc/rc0/protocols
# Should show: ... [rc-6] ...

# Test reception (Ctrl+C to stop)
ir-keytable -t -s rc0

Usage

Manual Entry

1. Open InfraFi on your Flipper
2. Select Send Credentials
3. Enter SSID, password, and security type
4. Review on the confirm screen, press Send
5. Point the Flipper at the server's IR receiver

NFC Tag

1. Write WiFi credentials to an NTAG213/215/216 using a phone app (e.g., NFC Tools)
2. Open InfraFi → Scan NFC Tag
3. Hold the tag to the back of the Flipper
4. Review credentials, press Send

Saved Networks

1. Previously transmitted networks are auto-saved to the SD card
2. Open InfraFi → Saved to browse them
3. Select a network to resend

ACK (Bidirectional Feedback)

1. Open InfraFi → Settings → set Wait for ACK to On
2. Send credentials as usual
3. After transmitting, the Flipper shows "Waiting for server response..." with a cyan LED
4. The daemon connects to WiFi and transmits the result back via IR:
   • Connected! — green LED, shows IP address
   • Failed — red LED
   • No response — times out after 30 seconds (credentials were still sent)

Note: ACK requires an IR transmitter on the server side. Many NUCs have a CIR receiver but no TX LED. Use --ack-device with an external USB IR blaster if needed.

Daemon

# Run in foreground with verbose logging (useful for testing)
sudo infrafid -f -v

# Use a separate IR device for ACK transmission
sudo infrafid -a /dev/lirc1

# Check service status
sudo systemctl status infrafid

# Watch logs
sudo journalctl -u infrafid -f

Protocol

InfraFi uses RC-6 Mode 0 IR protocol at 36kHz — the same protocol used by standard media center remotes. This is intentional: CIR receivers like the ITE8708 (found in Intel NUCs) have hardware decoders optimized for RC-6. Using the kernel's built-in RC-6 decoder (LIRC_MODE_SCANCODE) avoids the tiny hardware FIFO that overflows with custom raw protocols.

Each RC-6 message carries one byte of payload:

Field	Bits	Description
Magic	addr[7:4]	0xA — identifies InfraFi messages
Frame type	addr[3:2]	00=START, 01=DATA, 10=END
Pass	addr[1:0]	Retransmission attempt (0-3)
Command	cmd[7:0]	Payload byte

Credentials (Flipper → daemon): START(len) → DATA × N → END(crc8)

Payload is a standard WiFi QR string: WIFI:T:WPA;S:MyNetwork;P:MyPassword;H:false;;

ACK (daemon → Flipper): Same framing. Payload is OK:192.168.1.102 on success or FAIL on failure.

Project Structure

infrafi/
├── application.fam              # Flipper app manifest
├── flipper/                     # Flipper Zero app
│   ├── wi_fir.h/c               # App entry, ViewDispatcher + SceneManager
│   ├── wfr_encode.h/c           # RC-6 IR encoder + transmitter
│   ├── wfr_decode.h/c           # RC-6 ACK decoder (IR receive)
│   ├── wfr_nfc.h/c              # NFC NDEF WiFi tag parser
│   ├── wfr_storage.h/c          # SD card credential + settings storage
│   ├── protocol/
│   │   ├── wfr_protocol.h       # Shared protocol constants + structs
│   │   ├── wfr_protocol.c       # CRC-8, WiFi string builder/parser
│   │   └── version.h            # Shared version (Flipper + daemon)
│   ├── scenes/                  # UI scenes (menu, editors, confirm, transmit, NFC, saved, settings, about)
│   └── images/                  # App icon
├── daemon/                      # Linux daemon (infrafid)
│   ├── main.c                   # Entry point, CLI args, main loop
│   ├── wfr_lirc.h/c             # LIRC scancode reader
│   ├── wfr_decode.h/c           # RC-6 message reassembler
│   ├── wfr_network.h/c          # WiFi connector (NM/networkd/ifupdown) with rollback
│   ├── wfr_ack.h/c              # IR ACK transmitter (LIRC TX)
│   ├── Makefile                 # Build
│   ├── infrafid.service         # systemd unit
│   └── install.sh               # One-step install
├── debian/                      # Debian packaging
├── rpm/                         # RPM packaging
└── .github/workflows/           # CI/CD (ci.yml, release.yml)

Author

Alejandro Mora — github.com/amd989

License

MIT