Skip to main content
Version: 2.0 (Legacy)

Change Packet Source on a Pi

Configure packet sources and routing for OpenHD on Raspberry Pi systems.

Overview​

Packet source configuration controls:

  • Data Flow: How packets are routed through the system
  • Interface Selection: Which network interfaces handle traffic
  • Protocol Handling: How different packet types are processed
  • Performance Optimization: Optimize packet paths for latency

Packet Sources​

Video Packets​

  • Camera Interface: Direct camera capture
  • Network Stream: IP camera or network source
  • File Source: Video file playback
  • Test Pattern: Generated test video

Telemetry Packets​

  • Serial Interface: Direct flight controller connection
  • Network Source: Network-based telemetry
  • UDP Forwarding: Forwarded telemetry streams
  • MAVLink Proxy: Proxied MAVLink messages

Control Packets​

  • RC Input: Radio control signals
  • Network Commands: Network-based control
  • API Requests: REST API control packets
  • Emergency Override: Safety control packets

Configuration Files​

Main Configuration​

# Edit main OpenHD configuration
sudo nano /boot/openhd/openhd.conf

# Key settings:
VIDEO_SOURCE=camera  # camera, network, file, test
TELEMETRY_SOURCE=serial  # serial, network, udp
RC_SOURCE=network  # network, serial, disabled

Interface Configuration​

# Network interface settings
sudo nano /etc/openhd/interfaces.conf

# Configure specific interfaces:
WIFI_INTERFACE=wlan0
ETHERNET_INTERFACE=eth0
USB_INTERFACE=usb0

Service Configuration​

# OpenHD service configuration
sudo nano /etc/systemd/system/openhd.service

# Environment variables:
Environment="VIDEO_SRC=/dev/video0"
Environment="TELEM_PORT=/dev/ttyS0"
Environment="NETWORK_INTERFACE=wlan0"

Video Source Configuration​

Camera Sources​

# CSI Camera
VIDEO_SOURCE=camera
CAMERA_DEVICE=/dev/video0
CAMERA_FORMAT=h264

# USB Camera
VIDEO_SOURCE=usb
USB_CAMERA_DEVICE=/dev/video1
USB_CAMERA_FORMAT=mjpeg

# Multiple Cameras
PRIMARY_CAMERA=/dev/video0
SECONDARY_CAMERA=/dev/video1
CAMERA_SWITCHING=enabled

Network Sources​

# IP Camera Stream
VIDEO_SOURCE=network
STREAM_URL=rtsp://192.168.1.100:554/stream1
STREAM_USERNAME=admin
STREAM_PASSWORD=password

# UDP Stream
VIDEO_SOURCE=udp
UDP_PORT=5600
UDP_INTERFACE=eth0

File Sources​

# Video File Playback
VIDEO_SOURCE=file
VIDEO_FILE=/home/pi/test_video.mp4
LOOP_PLAYBACK=true
PLAYBACK_RATE=1.0

Telemetry Source Configuration​

Serial Configuration​

# UART/Serial Telemetry
TELEMETRY_SOURCE=serial
SERIAL_DEVICE=/dev/ttyS0
SERIAL_BAUDRATE=57600
SERIAL_PROTOCOL=mavlink

# USB Serial
TELEMETRY_SOURCE=usb_serial
USB_SERIAL_DEVICE=/dev/ttyUSB0
USB_SERIAL_BAUDRATE=115200

Network Configuration​

# UDP Telemetry
TELEMETRY_SOURCE=network
TELEMETRY_PORT=14550
TELEMETRY_PROTOCOL=mavlink
BIND_ADDRESS=0.0.0.0

# TCP Telemetry
TELEMETRY_SOURCE=tcp
TCP_PORT=5760
TCP_HOST=192.168.1.100

Forwarding Configuration​

# Telemetry Forwarding
TELEMETRY_FORWARD=enabled
FORWARD_PORTS=14550,14551,14552
FORWARD_BROADCAST=true
FORWARD_INTERFACES=wlan0,eth0

Control Source Configuration​

RC Control​

# Network RC
RC_SOURCE=network
RC_PORT=14555
RC_PROTOCOL=mavlink

# Serial RC
RC_SOURCE=serial
RC_DEVICE=/dev/ttyAMA0
RC_BAUDRATE=115200

API Control​

# REST API Control
API_CONTROL=enabled
API_PORT=8080
API_AUTHENTICATION=basic
API_USERS_FILE=/etc/openhd/api_users.conf

Advanced Packet Routing​

Packet Filtering​

# Configure packet filters
sudo nano /etc/openhd/packet_filter.conf

# Filter rules:
ALLOW_MAVLINK=true
BLOCK_HTTP=false
RATE_LIMIT_VIDEO=10Mbps
PRIORITY_TELEMETRY=high

Quality of Service (QoS)​

# QoS Configuration
sudo nano /etc/openhd/qos.conf

# Traffic classes:
VIDEO_CLASS=streaming
TELEMETRY_CLASS=interactive
RC_CLASS=realtime
BACKGROUND_CLASS=bulk

Load Balancing​

# Multi-interface load balancing
LOAD_BALANCE=enabled
PRIMARY_INTERFACE=wlan0
SECONDARY_INTERFACE=eth0
FAILOVER_TIMEOUT=5000

Interface Management​

Network Interface Configuration​

# Configure WiFi interface
sudo nano /etc/dhcpcd.conf

# Static IP configuration:
interface wlan0
static ip_address=192.168.1.10/24
static routers=192.168.1.1
static domain_name_servers=8.8.8.8

Interface Bonding​

# Create bonded interface
sudo nano /etc/systemd/network/bond0.netdev

[NetDev]
Name=bond0
Kind=bond

[Bond]
Mode=active-backup
MIIMonitorSec=1s

VLAN Configuration​

# VLAN interface setup
sudo nano /etc/systemd/network/vlan10.netdev

[NetDev]
Name=vlan10
Kind=vlan

[VLAN]
Id=10

Monitoring and Debugging​

Packet Flow Analysis​

# Monitor packet flow
sudo tcpdump -i wlan0 -n

# Monitor specific ports
sudo tcpdump -i any port 14550

# Monitor video streams
sudo tcpdump -i wlan0 -n udp port 5600

Interface Status​

# Check interface status
ip addr show
iwconfig
ifconfig

# Monitor interface statistics
cat /proc/net/dev
netstat -i

Performance Monitoring​

# Network performance
iftop -i wlan0
nload wlan0

# Packet loss analysis
ping -c 100 192.168.1.10
mtr 192.168.1.10

Troubleshooting​

Common Issues​

No Video Packets​

# Check video source
ls -la /dev/video*
v4l2-ctl --list-devices

# Verify camera permissions
sudo usermod -a -G video openhd

# Test camera directly
gst-launch-1.0 v4l2src device=/dev/video0 ! autovideosink

Telemetry Connection Issues​

# Check serial connections
ls -la /dev/tty*
sudo minicom -D /dev/ttyS0 -b 57600

# Test UDP telemetry
nc -u -l 14550
netstat -una | grep 14550

Interface Problems​

# Reset network interfaces
sudo ifdown wlan0 && sudo ifup wlan0

# Restart networking
sudo systemctl restart networking

# Check driver status
lsmod | grep wifi
dmesg | grep wlan

Diagnostic Commands​

# OpenHD status
sudo systemctl status openhd
sudo journalctl -u openhd -f

# Network diagnostics
sudo netstat -tulpn
sudo ss -tulpn

# Process monitoring
ps aux | grep openhd
htop

Configuration Examples​

Complete Air Unit Setup​

# /boot/openhd/openhd.conf
MODE=air
VIDEO_SOURCE=camera
CAMERA_DEVICE=/dev/video0
TELEMETRY_SOURCE=serial
SERIAL_DEVICE=/dev/ttyS0
SERIAL_BAUDRATE=57600
WIFI_INTERFACE=wlan0
FREQUENCY=2412

Ground Station Configuration​

# /boot/openhd/openhd.conf
MODE=ground
VIDEO_SINK=display
DISPLAY_DEVICE=/dev/fb0
TELEMETRY_FORWARD=enabled
FORWARD_PORTS=14550,14551
WIFI_INTERFACE=wlan0
FREQUENCY=2412

Dual Interface Setup​

# Primary interface for video
VIDEO_INTERFACE=wlan0
VIDEO_FREQUENCY=5745

# Secondary interface for telemetry
TELEMETRY_INTERFACE=wlan1
TELEMETRY_FREQUENCY=2412

# Failover configuration
INTERFACE_FAILOVER=enabled
FAILOVER_THRESHOLD=50
Configuration Changes

Always backup your configuration before making changes. Incorrect packet source configuration can disable system functionality.

Testing Required

Test packet source changes thoroughly in a safe environment before deploying to operational systems.

Love OpenHD?