SoftRF

Multifunctional DIY IoT-based general aviation proximity awareness system.

Features:

2-way raw data bridge between 868/915 MHz radio band and Wi-Fi ;
standalone, battery powered, compatible proximity awareness instrument that fits typical 2.25 inches hole ;
lightweight version to carry onboard of an UAV.

Compatibility ¹

Type	Protocol	Skytraxx	SoftRF
Radio	FLARM AIR V6	²
	OGNTP		³
	P3I		³
	UAT 978		⁴
	FANET+		³
Data	FLARM NMEA
	Garmin GDL90
	MAVLINK
	Dump1090 ⁵

¹ - it is necessary for a reader to distinguish the difference between statement "compatible" and statement "fully compatible".
SoftRF implements only a reasonable minimum of the protocols specs. No "bells and whistles" so far.
² - FANET+ can not receive FLARM. However it is able to transmit it.
³ - valid for Prime Mark II and Dongle Editions; valid for Standalone and UAV Editions with optional DIY SoftRF LoRa RF module
⁴ - Reception of traffic 'downlink' frames only. Valid for Standalone Edition with optional DIY SoftRF UAT module
⁵ - also known as "raw ADS-B"

Models

Model	Platform	First appearance	Comment
1 Prime 2 Standalone 3 UAV	Espressif ESP8266	Q4 2015	Prime model is no longer supported - use Prime MkII instead. ESP8266 platform will be phased out through year 2020 in favour of ESP32.
1 Prime Mark II 2 Standalone + adapter 3 UAV 4 SkyView EZ 5 Flight Recorder	Espressif ESP32	Q1 2018	Today's best platform
1 Raspberry Edition 2 SkyView Pi	Broadcom BCM283X (Raspberry Pi)	Q4 2018	Good for use together with RTL-SDR dongles to achieve additional 1090ES (and 978UAT) ADS-B air traffic reception.
UAT module	Texas Instruments CC13XX	Q1 2019	Resources of this platform are not sufficient to fit full SoftRF firmware. Unique RF radio specs are useful for UAT reception [ 1 , 2 , 3 ].
1 Dongle 2 Retro	STMicroelectronics STM32	Q3 2019	AcSiP S76G "3-in-1" system-in-package is doing good [ 1 , 2 , 3 ] . As well as STM32F103C8 "Blue Pill" (same MCU that STM32 OGN tracker uses) [ 4 , 5 ] .