System Design
Last update: 2022-06-29
Table of Content
Based on the study of a reference project from Livox.
Hardware#
Check the list of Components.
Block diagram#
Notes:
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All modules, except Livox’s, are 3.3V level, so they can be connected directly. This helps to omit USB TTL-to-COM.
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Raspberry Pi 3 B+ has a built-in WiFi module.
Power supply#
Wiring#
UART RX/TX problem
Here is some reports showing that Jetson boards have problems on UART RX/TX pin when connecting that port directly to an other board. It maily causes by the capitive loading on the pin, if the loop-back test does not have any problem.
If that problem happens, please add a 10 K pull-down resister on RX/TX pin.
Refer to Unreliable serial communcation via the UART TX/RX GPIO Pins.
Software#
The mapping node gets the pointcloud from the Lidar ROS driver node, the GNSS and IMU data from the APX-15 node and processes them together:
- Store pointcloud with timestamp
- Store GNSS with timestamp
- Store IMU with timestamp
- Align packets using timestamp
- Apply IMU to GNSS point, and stick geographical information to pointcloud