Ruby: System for video, telemetry and control of drones, planes and UAVs 05 Apr 2021
This article will show you how to build a complete digital link to be used for remote controlling vehicles like planes, drones, cars, UAVs, for sending/receiving data, telemetry and video. The system is built using hardware components available on the market.
All you need is the software from the downloads section and the minimal list of components from the hardware section below.
Check the Resources section for videos of Ruby in action;
What to expect: In terms of range:
On 2.4Ghz, using 200mW of power: about 2-3 km range (solid video); Range is shorter if you are in a city area with a lot of WiFi traffic;
On 5.8Ghz, using 400mw of power: about 3.5-4 km range (solid video); Range is pretty much the same in city and outside. I guess less 5.8Ghz band noise. This is how far I usually fly, not the range it can have. People regularly fly to 7-8 Km out on omnidirectional antennas only with solid link (see resources section for examples);
(This is on 720p, using CP antennas, 2-3db of gain; with high gain directional antennas range can be increased by an order of magnitude);
In terms of link quality: As good as it gets: 100% link quality, no break ups as in an analog video feed.
Being a digital link, end to end, gives you advantages over regular analog RF links, like: noise free video feed, ability to send data too (like telemetry and other custom data), error correction, data reliability, have more configurable parameters as it relates to the end to end video link, not just frequency and band; but also parameters like resolution, framerate, resilience and so on; and also enables some exotic scenarios like 3D video, camera switching and so on pretty much out of the box.
Ruby supports right out of the box:
Live view of the video feed and telemetry data;
Live control of the vehicle;
Low end to end latency of the video feed (as low as 80ms); Latency of telemetry and remote control is even lower, less than 10ms
Bind multiple models (just like a regular remote control) and switch between them, live;
Spectator mode; Allows others to be just spectators, watching the live video feed.
Software update on the vehicles over the air. So you just need to upgrade your controller and then you can upgrade your models without having to mess with them or having to take the hardware/SD card out; Controller can also be updated using a USB stick;
Supports multiple RF bands: 2.4Ghz and 5.8Ghz (433Mhz, 868Mhz, 915Mhz coming soon), the link is set for each model (if you have hardware that supports both frequencies bands); On the ground side you can use up to 4 radio interfaces for link reliability and different bands as needed;
Detailed info on link quality and video decoding stats
Multiple OSD layouts
Multiple camera profiles, live switching between them for different flight conditions;
Recording of all flights and video;
Bidirectional telemetry and custom data feeds. For telemetry, MAVLink and LTM are supported, other protocols are still in progress;
Extended settings, all settings can be changed on the fly using the OSD and menu (except some RC settings which would be dangerous to change while the vehicle is flying or armed);
Short startup times;
2 x Raspberry Pi (Zero, 2,3 or variants); One for the vehicle, one for the controller;
1 x Raspberry Pi Camera (any); For advanced setups, a DSLR or other HD camera can be used with a HDMI-CSI adapter board;
2 x Micro SD Cards (for the software itself);
2 x Good BECs/UBECs (for providing solid, high current, 5V supply for the PIs and network cards);
2 x WiFi network cards (that can do monitor mode and injection mode. Most popular are the ones with Atheros AR9271 chipset for 2.4ghz, like TPLink722N, or RTL8812AU chipset for 5.8Ghz, like ASUS USB AC-56); For advanced setups, multiple cards can be used on the controller for diversity RX or for custom separate link frequencies for video,telemetry, data.
1 x HDMI display; Or any device that can receive HDMI;
5 x Push buttons. This is for the menu navigation on the controller.
Basic controller wiring
Basic vehicle wiring
Recommended controller wiring
Recommended vehicle wiring
Hardware wiring for buttons and LEDs
Supported radio modules:
Here is the list of radio modules that are supported right now (more might be compatible, but this is just a list of tested modules):
5.8 Ghz band
ASUS AC56 USB
Realtek RTL8812AU chipset based modules
2.4 Ghz band
TPLink TL-WN722N (version 1)
Atheros AR9271 chipset based cards
915 Mhz band
868 Mhz band
433 Mhz band
Here are some videos of Ruby in action:
7km range on 5.8Ghz, 200 mW power, omnidirectional antennas: