Quickstart: Ground Agent - ADOS Documentation

What You Will Build

By the end of this page, you will have an ADOS Ground Agent running on a small SBC. It will receive WFB-ng video from your drone over a 5.8GHz radio link and relay that video to your laptop, phone, or HDMI monitor. You will be able to open Mission Control in your browser and see live video with under 100ms latency.

What is the Ground Agent?

The Ground Agent is the same ADOS Drone Agent software running in ground-station profile mode. At boot, the agent detects ground-station hardware (OLED display, GPIO buttons, RTL8812EU WiFi adapter, and the absence of a flight controller) and automatically configures itself as a receiver instead of a transmitter. Its core job: receive video from the air, relay it to your screen.

Hardware You Need

Minimum Setup (bench testing)

Component	Example	Approx. Cost
SBC	Raspberry Pi 4B (2GB+ RAM)	$45
WiFi adapter	RTL8812EU USB dongle	$15-20
Antennas	2x 5.8GHz SMA (dipole or patch)	$10-15
USB-C data cable	Laptop tether	$5
USB-C power source	Wall adapter or PD power bank	$10+

Full Standalone Setup (field use)

Add these for standalone operation without a laptop:

Component	Purpose	Approx. Cost
OLED display	1.3” SSD1306 I2C	$5
4x tactile buttons	Physical controls	$2
HDMI cable + portable monitor	Standalone video display	$50-100
USB gamepad	Manual flight control in kiosk mode	$20-30

On the Drone Side

Your drone needs the matching transmitter:

ADOS Drone Agent running on a companion SBC
An RTL8812EU USB WiFi adapter configured as WFB-ng TX
A camera feeding the video pipeline

The RTL8812EU chipset is the key component. It supports 5.8GHz monitor mode, which WFB-ng needs for its broadcast protocol. Other chipsets (RTL8812AU, RTL8811CU) may work but are less tested. The BL-M8812EU2 module is a common, affordable choice.

Installation

Step 1: Flash Your SBC

Start with a fresh OS image on your SBC:

Raspberry Pi 4B: Raspberry Pi OS Lite (Bookworm, 64-bit). Flash with Raspberry Pi Imager.
Radxa boards: Official Debian or Ubuntu image from the Radxa wiki.

Enable SSH during image creation. Set a hostname (for example, ados-ground).

Step 2: Boot and SSH In

Insert the SD card, connect Ethernet or WiFi, power on, and SSH in:

ssh pi@ados-ground.local
# or use the IP address
ssh pi@192.168.1.XX

Step 3: Plug in the RTL8812EU Adapter

Connect the USB WiFi adapter. Verify it is detected:

lsusb | grep -i realtek
# Should show something like:
# Bus 001 Device 003: ID 0bda:8812 Realtek Semiconductor Corp. RTL8812EU

Step 4: Install the Agent

The recommended path is to open Mission Control’s Flash Tool, pick ADOS Ground Agent, select your board, and paste the install command it shows over SSH. See Install paths for the full decision tree. The install script detects the ground-station hardware fingerprint:

RTL8812EU adapter present? Yes.
Flight controller on serial ports? No.
OLED on I2C bus? Check.
GPIO buttons wired? Check.

Based on these signals, it automatically sets profile: ground-station in the configuration. No flags needed. No manual profile selection.

The auto-detect logic uses a scoring system. If it finds an RTL8812EU adapter and no flight controller, the score tips toward ground-station profile. You can override this in /etc/ados/config.yaml if needed, but you almost never have to.

Step 5: Verify

ados status

You should see:

ADOS Drone Agent v0.89.2
Board: Raspberry Pi 4 Model B
Profile: ground-station

Services:
  ados-supervisor      active (running)
  ados-api             active (running)
  ados-health          active (running)
  ados-wfb-rx          active (waiting for signal)
  ados-hostapd         active (running)  [SSID: ADOS-GS-abc123]

WFB-ng:
  Mode: RX
  Channel: 161 (5805 MHz)
  Signal: waiting for drone

WiFi AP:
  SSID: ADOS-GS-abc123
  IP: 10.0.0.1
  Clients: 0

The WiFi AP is already running. The WFB-ng receiver is listening for a drone signal.

Connecting Your Devices

You have four ways to connect to the Ground Agent.

Option 1: Laptop over WiFi

On your laptop, join the WiFi network ADOS-GS-abc123 (the SSID includes your device ID)
Open your browser and go to http://10.0.0.1:4000
A captive portal / setup wizard may appear on first connection
Mission Control loads with the Ground Agent’s Hardware tab visible
When the drone is in range, video appears automatically

Option 2: Laptop over USB Tether

Plug a USB-C cable from the Ground Agent SBC to your laptop. The SBC exposes a CDC-NCM network gadget.

macOS (Sonoma+): Works natively. A new network interface appears. The SBC is at 192.168.7.1.
Windows 11: Works natively with CDC-NCM. The SBC is at 192.168.7.1.
Windows 10: Falls back to RNDIS. May need a one-time driver install.
Linux: Works natively. Run ip addr to find the new interface.

Open http://192.168.7.1:4000 in your browser.

USB tether is the most reliable data path. It does not depend on WiFi signal quality, and latency is consistently low. Use separate wall power or a USB-C power bank when video, WiFi AP, HDMI, or extra radios are active.

Option 3: HDMI Kiosk (No Laptop)

Connect an HDMI cable to the SBC and a portable monitor. The Ground Agent runs Chromium in kiosk mode, displaying the Mission Control HUD directly. Pair a USB or Bluetooth gamepad for manual flight control. The HUD shows the video feed, attitude, altitude, battery, and GPS overlaid on the video. This is the “backpack ground station” setup. SBC in a case, USB-C power bank, portable monitor, and gamepad. No laptop required.

1.3 inch OLED display on the ground station showing WFB-ng signal strength and connected clients

Option 4: Phone or Tablet

Connect your phone to the Ground Agent’s WiFi AP and open the browser. Mission Control is responsive and works on mobile screens. A native ADOS Android app with lower-latency video decoding is on a separate track. The browser path is the supported way to view from a phone today.

The Physical UI

If you have wired the OLED display and 4 tactile buttons, the Ground Agent provides a physical interface.

OLED Display (1.3” SSD1306, I2C)

Five screens, cycled by pressing the navigation buttons:

Screen	Shows
Link	WFB-ng signal strength, FEC stats, lost packets, bitrate
Drone	FC status, armed state, flight mode, battery, GPS fix
GCS	Connected clients (WiFi, USB, HDMI), active video streams
Net	Active uplinks (WiFi client, Ethernet, 4G), IP addresses, data usage
System	CPU, RAM, temperature, disk, uptime

Buttons

Four GPIO buttons with short-press and long-press actions:

Button	Short Press	Long Press
Up	Previous screen	(reserved)
Down	Next screen	(reserved)
Select	Toggle detail view	Enter setup mode
Back	Return to main	Factory reset (requires confirm)

Setup Wizard

On first boot (or after factory reset), the Ground Agent serves a captive portal setup wizard at http://10.0.0.1. This webapp walks you through:

Setting the WFB-ng channel (must match the drone’s TX channel)
Connecting to an existing WiFi network for internet access (optional)
Pairing with a Mission Control cloud account (optional)
Setting the WiFi AP password (optional, default is open)

The wizard is vanilla HTML and JS, about 50KB gzipped. It works on any device with a browser.

Web-based setup wizard with WFB-ng channel selector and WiFi configuration form

Uplink Matrix

The Ground Agent can connect to the internet through multiple paths simultaneously. This lets it relay cloud telemetry from the drone to Mission Control even when your laptop is on the Ground Agent’s local WiFi AP.

Uplink	How	When
WiFi AP	Always running	Local device connections
WiFi client	Join existing network	Relay cloud telemetry, software updates
Ethernet	Plug in cable (Pi 4B has GbE)	Fixed ground station installations
USB tether	Laptop shares internet	Piggyback on laptop’s connection
4G LTE	SIM7600G-H modem (optional)	Remote field deployments

Multiple uplinks can be active at the same time. The agent uses priority-based failover and health checks against the configured cloud endpoint to pick the best route. If 4G is enabled, a configurable data cap (default 5GB/month) prevents runaway usage.

Troubleshooting

No WiFi AP visible:

# Check if hostapd is running
sudo systemctl status ados-hostapd

# Check the WiFi adapter
iwconfig

WFB-ng not receiving:

# Check the WFB service
journalctl -u ados-wfb -n 30 --no-pager

# Verify the adapter is in monitor mode
iwconfig wlan1  # or whatever the RTL8812EU is assigned

# Make sure the channel matches the drone's TX channel in the setup webapp

USB tether not working:

# Check if the USB gadget is set up
ls /sys/kernel/config/usb_gadget/ados-ncm 2>/dev/null

# Enable USB tether from the setup webapp Network page if needed
sudo systemctl restart ados-usb-gadget-setup

Next Steps

Your First Flight

You have the stack set up. Time to fly.

Hardware Tab

Manage the ground station from Mission Control.

WFB-ng Configuration

Tune channels, FEC, and power settings.

Physical UI

Customize OLED screens and button mappings.

Mesh & Distributed Receive

Run two or three Ground Agents together for obstructed flight areas.

Three Deployment Roles

direct, relay, receiver. When to pick which.

​What You Will Build

​What is the Ground Agent?

​Hardware You Need

​Minimum Setup (bench testing)

​Full Standalone Setup (field use)

​On the Drone Side

​Installation

​Step 1: Flash Your SBC

​Step 2: Boot and SSH In

​Step 3: Plug in the RTL8812EU Adapter

​Step 4: Install the Agent

​Step 5: Verify

​Connecting Your Devices

​Option 1: Laptop over WiFi

​Option 2: Laptop over USB Tether

​Option 3: HDMI Kiosk (No Laptop)

​Option 4: Phone or Tablet

​The Physical UI

​OLED Display (1.3” SSD1306, I2C)

​Buttons

​Setup Wizard

​Uplink Matrix

​Troubleshooting

​Next Steps

Your First Flight

Hardware Tab

WFB-ng Configuration

Physical UI

Mesh & Distributed Receive

Three Deployment Roles

What You Will Build

What is the Ground Agent?

Hardware You Need

Minimum Setup (bench testing)

Full Standalone Setup (field use)

On the Drone Side

Installation

Step 1: Flash Your SBC

Step 2: Boot and SSH In

Step 3: Plug in the RTL8812EU Adapter

Step 4: Install the Agent

Step 5: Verify

Connecting Your Devices

Option 1: Laptop over WiFi

Option 2: Laptop over USB Tether

Option 3: HDMI Kiosk (No Laptop)

Option 4: Phone or Tablet

The Physical UI

OLED Display (1.3” SSD1306, I2C)

Buttons

Setup Wizard

Uplink Matrix

Troubleshooting

Next Steps