ADSBee m1421: The World’s Smallest Dual-Band ADS-B Receiver

'Pants for Birds' recently announced the release of the ADSBee m1421 module, which they describe as the world's smallest dual-band ADS-B receiver.

The ADSBee m1421 is based on the LR2021 chip, and while it supports dual-band 1090 MHz and 978 MHz UAT, they note that 1090 MHz support is somewhat limited. This is because the LR2021 can listen to only one Mode S packet type, so it cannot receive squawk codes and receives fewer non-ADS-B packets. This, however, does not affect the usual application: tracking aircraft. The LR2021 also cannot implement timestamping or RSSI, meaning that MLAT is not possible.

Apart from its ADS-B capabilities, they have also broken out the LR2021’s 2.4 GHz front end as a waveguide, allowing it to be used as a mesh transmitter or LoRa receiver.