INAV Nexus X - Benewake TF Lunar Range Finder not working

[Maulaag]

Current Behavior

First of all: Many thanks to the great guys who provided us with INAV for Nexus X

For more precise autolanding of my fixed wing I added a Benewake TF Lunar Range Finder.
It connects perfect up to the point where the Sonar Icon turns blue, but the reading is allways -1m.

Steps to Reproduce

• same behavior on all UARTS (tried UART 1, 3, 4, 6)
• swapping TX/RX pins does not resolve the problem
• checked Range Finder Output on PC with SerialPort Assistent. Benewake HEX Protokoll is beeing sent
• checked Range Finder Health on PC with TF-Luna GUI, working good
• provided steady 5V input via battery to the nexus

Expected behavior

Range Finder should work and show Readings in Sensors Tab under Sonar

Suggested solution(s)

Im am no expert here, but maybe the Range Finder input is not parsed correctly?

Additional context

status

INAV/NEXUSX 9.0.1 Feb 13 2026 / 06:53:16 (d44f2cf)
GCC-13.2.1 20231009
System Uptime: 33 seconds
Current Time: 2041-06-28T01:04:00.000+00:00
Voltage: 0.78V (0S battery - NOT PRESENT)
CPU Clock=216MHz, GYRO=ICM42605, ACC=ICM42605, BARO=SPL06, RANGEFINDER=BENEWAKE
STM32 system clocks:
SYSCLK = 216 MHz
HCLK = 216 MHz
PCLK1 = 54 MHz
PCLK2 = 108 MHz
Sensor status: GYRO=OK, ACC=OK, MAG=NONE, BARO=OK, RANGEFINDER=OK, OPFLOW=NONE, GPS=OK
Stack size: 6144, Stack address: 0x20010000, Heap available: 1692
I2C Errors: 0, config size: 10172, max available config: 16384
ADC channel usage:
BATTERY : configured = ADC 3, used = ADC 3
RSSI : configured = none, used = none
CURRENT : configured = none, used = none
AIRSPEED : configured = none, used = none
System load: 11, cycle time: 1028, PID rate: 972, RX rate: 49, System rate: 9
Arming disabled flags: NAV RX CLI
WAITING FOR GPS FIX
OSD: not enabled
VTX: not detected
GPS: HW Version: UBLOX10 Proto: 34.09 Baud: 115200
SATS: 0
HDOP: 99.990
EPH : 99.990 m
EPV : 99.990 m
GNSS Capabilities:
GNSS Provider active/default
GPS 1/1
Galileo 0/1
BeiDou 0/1
Glonass 0/0
Max concurrent: 3

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[Maulaag]

Did some more testing and got a vl53l1x Sensor, which I connected to PortC ( I2C according to https://github.com/iNavFlight/inav/blob/master/docs/boards/NEXUSX.md).

Again, the range finder symbol turns blue, but I only get readings of -1m.

Could it be that Range Finder does not work at all in the NEXUSX build?

status

INAV/NEXUSX 9.0.1 Feb 13 2026 / 06:53:16 (d44f2cf)
GCC-13.2.1 20231009
System Uptime: 35 seconds
Current Time: 2041-06-28T01:04:00.000+00:00
Voltage: 0.02V (0S battery - NOT PRESENT)
CPU Clock=216MHz, GYRO=ICM42605, ACC=ICM42605, BARO=SPL06, RANGEFINDER=VL53L1X
STM32 system clocks:
SYSCLK = 216 MHz
HCLK = 216 MHz
PCLK1 = 54 MHz
PCLK2 = 108 MHz
Sensor status: GYRO=OK, ACC=OK, MAG=NONE, BARO=OK, RANGEFINDER=OK, OPFLOW=NONE, GPS=NONE
Stack size: 6144, Stack address: 0x20010000, Heap available: 1692
I2C Errors: 50, config size: 10172, max available config: 16384
ADC channel usage:
BATTERY : configured = ADC 3, used = ADC 3
RSSI : configured = none, used = none
CURRENT : configured = none, used = none
AIRSPEED : configured = none, used = none
System load: 10, cycle time: 1017, PID rate: 983, RX rate: 59, System rate: 9
Arming disabled flags: NAV RX CLI
WAITING FOR GPS FIX
OSD: not enabled
VTX: not detected