Garmin LiDAR-Lite v3 vs. v3HP

Here’s Hermione, photographed with the Pi NoIR camera, showing the Garmin LiDAR-Lite v3 IR laser beam on the ground:

H's LiDAR beam

H’s LiDAR beam

Here’s Penelope’s equivalent:

Penelope's lack of laser

Penelope’s lack of laser

They are running identical code but Hermione gets data back over I2C for the distance whereas Penelope gets ‘1’ meaning no laser signal received, either for out-of-range, bad reflection direction, or in this case, the IR laser is not running.  There is no way to manager the laser in soft- or hardware.

Not a great start for the LiDAR-Lite v3HP 🙁

P.S. I’ve found and updated the different between the I2C registers between the GLL v3 and v3HP. However none of these mention control of the laser, and with the GLL v3HP using the new I2C registers code, the laser is still not showing.   😥

P.P.S. It seems the new v3HP I2C registers don’t support a couple of functions I was relying on:

  1. set sampling rate to 10Hz so I could always read the latest height from the ground when the lateral pixel distance was know.
  2.  always able to read the latest values automatically – this seems now to require a WRITE then a READ whereas previous, only a READ was required for the latest setting.

On the plus side it’s more accurate (apparent) though without an operating laser, that a moot point!

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