RAK2245 on RPi - devices Join but most Uplinks lost

Issue: devices Join via OTAA and broadcast data regularly but most Uplink packets are not seen

Setup: RPi 4B bullseye, RAK2245 hat, Dragino LDDS75 and LSN50v2 devices, AU915

Server: Chirpstack v3 with TTN


  • installed several months ago using RPi image (buster), experienced this problem, set aside

  • re-installed now from GitHub repository on clean bullseye, same problem

  • selected Chirpstack, AU915 freq range

  • created device profiles and devices for LDDS75 and LSNS75, incl Device EUIs and App Keys

  • both devices rapidly Join via OTAA

  • both devices transmit every 20 mins but very few of these packets are seen (less than 10%). those that are seen decode correctly and show correct values

  • RSSI is about -50 for both devices in seen packets

  • i’m a newbie to radio (but very familiar with linux/RPi) so be gentle

  • after lots of searching the only clue i have found is a hint that AU915 has a lot more than 8 frequencies but RAK supports up to 8 so maybe devices are using too many different frequencies - i’m ignorant enough to think that’s feasible