All 12 boot-time calibrations passed. The debug output confirmed it:

Debug: Init Calibration Status = 0x1ffe

0x1FFE means bits 1–12 are all set — every RF calibration succeeded. The sensor advanced to State 1. Then sensorStart returned Error -1 and the data port stayed silent.

State 1 means configured but not running. The error was happening in the chirp engine, after calibration, before any data could flow.

The math I didn’t check

The regulatory band for the IWR6843AOP is 60.0–64.0 GHz.

My profileCfg had:

profileCfg 0 60.75 30 7 57.14 0 0 70 1 256 5209 0 0 30

Bandwidth = freqSlopeConst × rampEndTime = 70 MHz/μs × 57.14 μs = 4.0 GHz.

End frequency = 60.75 + 4.0 = 64.75 GHz.

That’s 750 MHz past the top of the band. The calibrations run at boot and don’t care — they test the RF chain independently of the chirp profile. But the chirp engine validates the sweep boundaries before starting, and it refused.

No error message explaining this. Just Error -1.

The fix

Change startFreq from 60.75 to 60.0 so the chirp ends exactly at 64.0 GHz. Sensor advanced to State 2 in under a second.

profileCfg 0 60.0 30 7 57.14 0 0 70 1 256 5209 0 0 30

The check to run before every config change

endFreq = startFreq + (freqSlopeConst_MHz_us * rampEndTime_us / 1000)

For the IWR6843AOP: endFreq must be ≤ 64.0 GHz. If it’s over, sensorStart will silently fail with Error -1 every time, regardless of calibration status.

The TI E2E forums have multiple threads about this exact error. The answer is buried in replies. Saving you the search.