Troubleshooting

Refer to the mLRS Official Documentation for Software Troubleshooting.

For NOVALINK-specific issues, please see below:

Won’t Bind

  • Ensure both Tx and Rx are in bind mode by pressing the Bind/DFU button and holding for >4 seconds or until lights flash.

  • Ensure Tx and Rx are both getting at least 7.0V.

  • Verify firmware, re-flash if necessary with full chip erase (requised DFU mode and STM32CubeProgrammer)

  • Verify bind phrase

  • Turn off privacy mode

No Power

  • Check voltage with multimeter

  • Nominal current should be <300mA for both Rx and Tx. Tx will sometimes be higher if Wireless Bridge is enabled. Ensure proper power supply.

Transmitter Can’t Connect with Radio Controller

  • Ensure proper installation of JR Bay Adapter

  • Try different ethernet cable

  • Try shorter ethernet cable

  • Ensure H7 radio is >2.12.4 for EdgeTX

  • Update LUA script

Poor RF Range (<10km)

  • Antennas installed incorrectly. Check SWR and measure with antenna in aircraft.

  • Calibrate VNA and test antenna again

  • Using wrong antenna connectors. Use ONLY SMA-type with NOVALINK.

  • RF output power too low

  • Noisy RF environment (try to fly away from the city and where people are)

  • Radio jammers or Amateur Radio activity on 433MHz band nearby. Verify with spectrum analyzer and directional antenna.

  • Electrical noise in power supply going to Tx/Rx. Verify with oscilloscope.

  • Obstacles blocking range (ex. building, hill/mountain, etc.)

  • Curvature of earth getting in way - move to higher elevation, fly higher.

  • Link drops before RSSI is at minimum value - obstacles, noise, poor RF environment degrading signal

  • Move Transmitter physically away from radio controller >6ft

  • Place radio controller in Faraday Cage. In other words, place it in a tin-foil box. See RF Testing Example

  • Use higher-gain antenna

  • Try new coax cable - may be damaged by bending, cracks, etc.

  • Do manual range test without attached to aircraft to determine if the airfraft is detuning antenna or introducing noise in to RF system.

  • Try different or new Tx and Rx module.

  • Try different antenna

  • Try different JR Bay Adapter (bad connector - check power)

  • RF connectors not screwed in properly

RF Output Power Low

  • Check input voltage (use multimeter)

  • Device may be overheating

  • RF power meter damaged (ImmersionRF RF Power Meter is notorious for incorrect/low RF power measurements and is also easily damaged in general)

Overheating

  • Verify with thermal camera

  • Add heatink

  • Add airflow over part

  • Check antenna

  • Check antenna connection to Tx/Rx

  • Lower RF output power and test with power meter

  • Attach 50 ohm load instead of antenna to root out antenna impedance mismatch