Ruby Digital FPV System (2024)

Here you find all the information on how to connect all the hardware components to create a Ruby system:

• Hardware Components
• Supported SBC boards
• Supported radio modules
• Supported cameras
• Wiring and connections
• Buttons
• Serial Ports
• Ruby Addons

Hardware Components:

Ruby supports a variety of hardware components in terms of cameras, radio modules, SBCs.Below is the minimum list of required components to create a fully working system.

Note: You can mix and match hardware as needed. That is, you can use different Pi boards for vehicles and controllers and use different radio modules on the same link (assuming they do support the frequency you will be using).

Here is the full list of supported hardware components:

Wiring and connections:

If you are new to electronics and DYI projects, it's recommended you start with the basic wiring and connections as in the pictures below as it's easier and faster to do and have a system up and running:

Note! If you have critical usage scenarios or you plan to use Ruby in environments with vibrations, it is recommended to replace all USB cables and connectors with wires that are soldered to the boards at each end. This gives a more robust system in terms of reliability and resilience to vibrations:

Direct wiring of USB connections:

It is recommended that you wire directly the USB connections, from Pi/Radxa to the radio cards, to not use USB cables and connectors, to avoid vibration issues, using the points on the Pi board that give you direct access to the USB data lanes, as in the pictures below:

Note: On Raspberry Pi 4, the video output is generated on the HDMI Output Port 0. So you should connect a display to that port. The HDMI Output Port 1 is not used.

Buttons:

The user interface in Ruby can be accessed and navigated using a USB keyboard, a rotary encoder or push buttons.The more convenient way, long term, is to use push buttons for menu navigation.To do so, on the controller you need to add the 4 navigation buttons.
No buttons, rotary encoders or USB keyboard are needed on vehicles.

Buttons Wiring:

The user interface on the controller can be accessed in Ruby (besides keyboard and rotary encoders) using 4 push buttons for: Menu, Cancel, Up and Down.There are also some optional buttons, that enable auxiliary functions in Ruby like starting a video recording, taking a picture, changing OSD layouts, changing camera settings on the fly and more. They are not mandatory, but make life easier and the user experience more enjoyable.

Please see the Peripherals section to see how to setup a rotary encoder.

If you choose to use buttons for interface navigation, you need to wire the buttons as in the pictures below. There is a common rail to all buttons, connected to 3.3v, and one individual connection from each button to a GPIO pin on the Raspberry Pi/Radxa boards:

You can then assign what actions to do when pressing the Quick Actions buttons from the Preferences menu:

Other hardware connections:

There are few other hardware connections you can make to Ruby, that are optional, but can be used if needed.
They are as follows (only for Raspberry Pi boards):
* A LED that will blink when video recording is turned on (on the controller side);
* A LED that will blink when there are major hardware or software issues (on the controller side);
* A GPIO pin (GPIO 19) that you can use to force a Pi to boot as a vehicle/relay, even if it has no camera (on the vehicle side);
* A GPIO pin (GPIO 26) that you can use to force a Pi to boot as a controller, even if a camera is detected (on the controller itself);

The wiring for those is as in the picture below:

Serial Ports:

Ruby can communicate with external devices using serial interfaces (UART).
The serial interfaces can be used to communicate with a flight controller, with a camera gimbal, a receiver or other devices based on each individual application.
If you need more than one serial interface, to connect to multiple devices, you can add any number of USB to serial adapters and connect them to the USB ports on the Pi, as in the picture below:

Note: Use only brand name USB to serial adapters or ones with CP2109 or CP2102 chipsets. The USB serial adapters with CH340 chipset are not supported.
Note: The CP2102 chipsets are the most reliable ones and work in all conditions. The CP2109 might be incompatible with some Pi boards, depending on the manufacturer.

All available serial ports will be shown in the Ruby UI interface and you can change the parameters and usage for each individual port.

Most of the times, on the vehicle, you want to connect your flight controller to the Raspberry Pi so that Ruby can receive telemtry info from the flight controller and to send data and commands to the flight controller.
You need to connect the serial interface as in the picture below:

Note: Keep in mind that Raspberry Pi uses 3.3 volts logic levels. Most modern flight controllers (Pixhawk, Cube, STM32, etc) also use 3.3 volts so nothing special needs to be done. If you have an old or special flight controller that used 5 volts logic levels, you need to insert a level shifter.

Ruby Hardware Peripherals:

You can add optional hardware components to Ruby controller that will extend the functionality with new features.

Raspberry Pi Pico Add-on:

To expand the I/O capabilities of Raspberry Pi, to add more UART interfaces, analog inputs, SBUS/IBUS/PPM RC input and other future extensions, a small Raspberry Pi Pico is connected to the Pi controller using the I2C interface.
The add-on Pico is powered directly from the main Pi:

To add peripherals to the Pico Pi, use the following diagram:

Note: Raspberry Pi Pico is using 3.3v levels on the GPIO pins, but from the tests done, it can handle just fine 5V IBUS/SBUS input. You should add a 5v -> 3.3v level shifter on the IBUS/SBUS input if your source signal is using 5v levels.

You need to flash the Ruby software on your Pico. See the Downloads section for instructions on how to flash a Raspberry Pi Pico and to get the latest software for the Pico.

I2C Interface:

Ruby can use I2C interface and communicate with external devices.
You can add multiple devices on the same I2C interface and all I2C devices that are detected at boot will show up in Ruby UI interface and you can change parameters for each individual I2C device.

Note: Raspberry Pi uses 3.3 volts logic levels. If you need to connect I2C devices that use 5 volts logic levels, use a level shifter as in the picture above.