AirGradient Forum

O-1PST – 4-4-4 / 5-5-5 blue LED pattern after clean flash + all basics ruled out

O-1PST DIY kit (new)

  • All wiring confirmed correct (PM1 = PM sensor, PM2 = CO2 sensor, both fully seated)
  • Using the exact same power adapter + cable that works perfectly on my indoor AirGradient
  • WiFi signal strong at the location (same spot where indoor unit works fine)
  • Indoor unit on same 2.4 GHz network works perfectly
  • After multiple full erase + flash + re-setup: blue LED does exactly 4 blinks ×3, then 5 blinks ×3, then completely off
  • Faint internal CO2 LED is blinking (board + CO2 sensor alive)
  • App shows “seen once” with new timestamp each power cycle
  • Pattern repeats identically every time

All common causes (power, wiring, signal, network) ruled out. Any ideas??