When complying with the 2020 ADS-B mandate, you'll still need a fully functional Mode A/C transponder. That means a transponder-based ADS-B solution is often the best choice for aging aircraft that haven't seen a transponder upgrade since the Reagan era. If the aircraft flies above 18,000 feet, there's no choice but to go with an ADS-B transponder. Montana-based uAvionix now looks to be aggressively pursuing that competitive market with its new 1090nano, a chipset that it says represents the core technology it will use in certified ADS-B transponders for both the GA and UAS markets.
This is a companion discussion topic for the original entry at https://www.avweb.com/ownership/more-dime-sized-ads-b-tech-from-uavionix