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TDC data processing

iliasam edited this page Dec 18, 2023 · 11 revisions

Simple diagram showing how TDC data is processed in lidar firmware.

See source code and source code for scanning mode.

"Reference zero distance, BIN" is calculated during scanning using measurement distance to a "reference plate".
Amplitude changing compensation is used to compensate time "Walk error".

"BIN length" value is stored in Flash, this value must be measured and programmed to the MCU during BIN length calibration.
See "BIN Length" value in "LidarTestingUtility".
Default value ("DEFAULT_DIST_BIN_LENGTH" constant in "config.h") is near 14.5 mm/BIN.
This value is calculated like (90ps * 3e8m/s / 2) = 13.5 mm/BIN, where 90ps is resolution of TDC-GP21.

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