Radio RX888

An experimental native driver that talks to the radio over USB itself.

New in 0.2.6, not in 0.2.5.

Still being hardened. The driver was written from the open SDDC protocol and tested against a simulated FX3; the MkII on real hardware is still being hardened. Please report what you see.

What it does

OnAir talks to the radio over USB itself (no vendor library). HF (direct sampling, 64 or 128 Msps ADC clock) and VHF / UHF (R828D tuner, up to about 1.75 GHz) are covered; the sample rate list is 0.25 to 64 Msps.

Windows quick start

1. In Zadig turn on List All Devices.
2. Install WinUSB for 04B4:00F3 and again for 04B4:00F1 (RX888mk2).
3. Unplug and replug the cable on a USB 3 port.
4. Press refresh in OnAir's radio list.

If the Cypress driver from the official RX-888 / HDSDR installer still owns the device, repeat Zadig on 00F1 and replug. A LimeSDR-USB shares 04b4:00f1; OnAir tells them apart by the product name.

Firmware

The radio has no program of its own: the FX3 needs SDDC_FX3.img. Official OnAir packages ship it in the codecs folder (on Linux in lib/onair/). OnAir loads it into the radio's RAM when needed; nothing is flashed. A hand-built copy may need the file from the SDDC_Driver releases page, or the environment variable ONAIR_RX888_FIRMWARE pointing at it.

Requirements and settings

• It must be on a USB 3 port: the stream is up to 256 MB/s. On Linux a udev rule for 04b4:00f1 / 00f3 is needed.
• Settings: ADC clock (auto, 64, 128 MHz or exact), input (auto, HF, VHF), HF attenuator, dither, randomiser, PGA, bias tee.