Introduction
The Doodle radio is a network radio unit that provides an IP network between a ground station and the network on-board the aircraft. The network can be used to access flight controller data, video feeds (if equipped), and access to devices connected to the RJ-45 port located on the bottom of the aircraft.
Network Topology
The network between the ground station and the aircraft network has a flat topology. All equipment is visible from any address on the network. The wireless bridge is transparent.
The ground unit is equipped with two RJ-45 ports. Both ports are bridged to the same IP network. The drone is equipped with an internal 10/100 mbit network switch for aircraft systems and payloads. It is also equipped with an RJ-45 connection located on the bottom of the aircraft for use with arbitrary payloads, computers, or for diagnostic purposes.
IP Addresses and Ranges
The IP address range for each aircraft is a unique /24 address range. The range is of the form:
10 . [Client Specific ID] . [Aircraft Specific ID] . [Device Address]
There is a DHCP server enabled on both the ground and air-side radios. Each radio has a different DHCP range. This allows ground equipment to be differentiated from air equipment. The DHCP ranges and reserved address are listed below
Customer Reserved IP Ranges (Assigned through DHCP or free for static assignment)
51-99: Air-Side DHCP Range
151-199: Ground-Side DHCP Range
200: Customer Reserved Priority Access IP Address
201-254: Customer Reserved Static IP Range
Aircraft Reserved IP Ranges (Reserved for BFD use)
1-49: Air Address (reserved for aircraft components)
101-149: Ground address (reserved for ground station components)
50, 100, 150: Reserved for Future Use
Differentiated Services
The radio link is capable of prioritizing packets that meet predefined criteria. This allows the link to prioritize command and control data. The link is set up to give the highest priority to the flight controller link. The next highest priority is assigned to video data that may be supplied by optional FPV equipment, payload cameras, or a video encoder. The next priority is general data on the network. In this was the data required to control the aircraft is always available to the operator.
Priority Access IP Address
A special IP address has been designated with priority access. Any device placed on the network with the designated static IP address (listed in the UAS Radio and Network Sheet as the “Priority Access IP Address”) will have the same priority as aircraft video data. This may be used if payload data if of particular importance and should take priority over other network traffic.
Radio Module Settings
The radio module located in the aircraft is a Doodle labs embedded radio unit. This unit is similar to a home router in that it has an IP address and a configuration web page that may be used to change radio specific settings. The radio may also be accessed by SSH for more advanced use. The radio module is running a customized version of OpenWRT. Many of the commands and configuration settings will be familiar to users of that platform.
To connect to the radio settings page, connect a computer to an ethernet port located on either the aircraft or the ground unit. Power on the radio(s) to be adjusted. Navigate to the IP address of the radio (see the UAS Radio and Network Sheet) and enter the username and password provided (see the UAS Radio and Network Sheet).
Connection Instructions
The radio provides a standard DHCP server. To connect to the drone network configure the ethernet adapter of the desired computer for DHCP and use a cat5e or cat6 cable to connect the computer to either port of the ground radio or aircraft.
Connecting to the Flight Controller
Follow the instructions above to connect the computer to the network
Open a Mavlink compatible Ground Control Station software
Mission Planner
In the top right corner select the drop down menu and select UDPCI
Enter the IP address of the aircraft serial adapter
Enter 14550 for the local port and click ok
QGroundControl
Select the Purple icon in the top left of the screen to go to settings
Select Comm Links in the sidebar
Click Add at the bottom of the screen
Enter a name for the Vehicle
Choose type UDP
Enter 14550 for the listening port
Under target host click add
Enter the flight controller IP address
Listed in the UAS Radio and Network Sheet included with the aircraft
It may also be listed on a stick on the ground radio unit
Click Ok
Select the new link in the menu
Click connect