# Packet Forwarder

SSH to the Raspberry Pi.

Run `raspi-config` and

- Enable SPI
- Enable I2C
- Turn off login shell but keep serial port active
- Reboot

Clone the packet forwarder repository: `git clone https://github.com/Lora-net/sx1302_hal.git`.

Go into the repo and run `make`.

Make pf user + give permissions

- `sudo useradd -m -s /usr/sbin/nologin pf`
  - `-m`: create home
  - `-s /usr/sbin/nologin`: don't allow logging in; the user's only purpose is to own the packet forwarder process
  - `pf`: the username
- `sudo usermod -aG gpio,spi,i2c,dialout pf`

From the packet forwarder repo, copy files to pf user's home and set permissions:

```sh
sudo cp packet_forwarder/{global_conf.json.sx1250.US915,lora_pkt_fwd} /home/pf
sudo cp tools/reset_lgw.sh /home/pf
sudo chown pf:pf /home/pf/{global_conf.json.sx1250.US915,lora_pkt_fwd,reset_lgw.sh}
sudo chmod +x /home/pf/{lora_pkt_fwd,reset_lgw.sh}
```

Modify the packet forward config at `/home/pf/global_conf.json.sx1250.US915`. Change `gateway_ID` to something nice (????). 8 bytes (16 uppercase hex characters)

Modify the `reset_lgw.sh` file to have the following GPIO values, [ref](https://wiki.seeedstudio.com/WM1302_module/#step4-run-semtech-sx1302-packet-forwarder):

```sh
SX1302_RESET_PIN=17     # SX1302 reset
SX1302_POWER_EN_PIN=18  # SX1302 power enable
SX1261_RESET_PIN=5     # SX1261 reset (LBT / Spectral Scan)
AD5338R_RESET_PIN=13    # AD5338R reset (full-duplex CN490 reference design)
```

Create SystemD unit file at `/etc/systemd/system/packet-forwarder.service`:

```systemd
[Unit]
Description=SX1302 Packet Forwarder
After=network.target
StartLimitIntervalSec=0

[Service]
Type=simple
Restart=always
RestartSec=1
User=pf
WorkingDirectory=/home/pf
ExecStart=/home/pf/lora_pkt_fwd -c global_conf.json.sx1250.US915

[Install]
WantedBy=multi-user.target
```

Start and enable `sudo systemctl enable --now packet-forwarder.service`.

Check that it is running with `sudo systemctl status packet-forwarder.service`.