NDT tuning process

[MJJ]

About 44 minute mark of Measuring distance with the Nordic Distance Toolbox - Nordic Semiconductor, Paal mentions tuning is needed for custom boards. In slide 38 of /cfs-file/__key/communityserver-discussions-components-files/4/3731.Measuring_5F00_distance_5F00_with_5F00_Nordic_5F00_Distance_5F00_Toolbox_5F00_slides.pdf it mentions "Code is tuned for the device and the board so changes will require to trim offset and gain".

In \ncs\v1.9.0\nrfxlib\nrf_dm\include\nrf_dm.h there is struct nrf_dm_config_t -> member dist_offset_err.

In \ncs\v2.1.0\nrfxlib\nrf_dm\include\nrf_dm.h I do not see an error offset.

I have not seen an update in NCS Release Note around this topic between NCS v1.9.0 - NCS v2.1.0.

Does anyone know how NDT should be tuned for customer hardware or if it is needed with NCS v2.x?

[tesc]

Hi,

The library handles gain by itself now, so there is no gain tuning required.

Depending on the board and more importantly the antenna there might be a different delay in the measurement, which gives an offset in the value reported by the library. We recommend doing a calibration test at a known, short distance of a small number of wavelengths, for instance at 60 cm. (60 cm is around two feet, for those who prefer non-SI units.)

Please note that at the time of writing, the Distance Measurement module is still in experimental. This means the solution can be expected to change. See software maturity categories for details on software maturity classification.

Regards,
Terje