vl53_400_lib 0.1.2

Python library for using the VL53-400 laser rangerfinder via serial port

vl53-400 Laser RangeFinder Library

Python Library and CLI for the VL53-400 laser rangefinder with Serial interface

NOTE: This is still a bit underconstruction. The Functions here do seem to work, but not all capabilities of the chipset is handled yet. You should be able to do measurements though.

This is for the MJ-VL53-400 unit Sold by MengJie.

Its basically a STMicroelectronics VL53L0X with a UART so you can use it via a USB -> TTL Serial adapter and not deal with IIC or Modbus.

It seems to actually be a WitMotion Laser Distance Sensor WT-VL53L0 Distance Module UART Output repackaged by MengJie

• Menjie MJ-VL53-400 User Manual
• ST API Info

Library Functions

Class device_access.SerialAccess contains all the methods for using it

Instantiate the RangeFinder Class

RangeFinder(serial_port: str, baud_rate: int, timeout: int, debug: bool)

Arguments

Need to supply all of these for now

• serial_port: str - The serial port the RangeFinder is connected too such as /dev/tty.usbserial-910
• baud_rate: int - Baud Rate. Should be 115200
• timeout: int - Timeout. Should use 1
• return_rate: float - Should be one of "0.1", "0.2", "0.5", "1", "2", "5", "10", "20", "50", "100"
• debug: bool - Set True to enable debugging, otherwise False

Example:

    from vl53_400_lib import RangeFinder

    range_finder = RangeFinder("/dev/tty.usbserial-910", 115200, 1, 10, False)

Reset

This method resets the Rangefinder.

    range_finder.reset()

Set Sensor mode

This method sets the sensor mode between serial (default), modbus and iic.

Arguments

• mode: str - The mode to set. (serial, modbus, iic) Probably only want to use serial or modbus. modbus will stop the serial updates

Example:

    range_finder.set_sensor_mode("modbus")

Get Return Rate

Gets the return rate setting

Returns

str: The return rate in Hz

Example

    rate = range_finder.get_return_rate()

Set Return Rate

Arguments

rate: str - One of "0.1", "0.2", "0.5", "1", "2", "5", "10", "20", "50", "100"

Example

    range_finder.set_return_rate("0.5")

Stream Data

Only prints the data to stdout

This method streams data from the serial port to stdout. It does not return anything and will block until interrupted if loop is True.

Argument

loop: bool - Whether or not to loop forever. Defaults to True. Set to false to exit after one loop (for testing)

range_finder.stream_data(True)

Get Distance

This is the main workhorse function to use. It will fetch the distance data from the Rangefinder Reads data from the serial port and returns a dictionary.

Returns

data: dict - A dictionary containing the distance and units, as well as the state and state_code.

    data = range_finder.get_distance()

Main.py has a CLI for exercising all functions

Install and run cli

git clone 
cd vl53_400_lib
poetry install

To run the cli:

> poetry run vl53 --help

Usage: vl53 [OPTIONS]

Options:
  --serial-port TEXT              The serial port to connect to.
  --baud-rate INTEGER             The baud rate to use.
  --timeout INTEGER               The timeout to use.
  --return-rate [0.1|0.2|0.5|1|2|5|10|20|50|100]
                                  Set Return Rate in Hz
  --mode [serial|modbus|iic]      Comm mode (modbus stops serial spew)
  --op [stream|get_return_rate|lstream|reset]
                                  The operation to perform.
  --debug                         Enable debug logging.
  --help                          Show this message and exit.

TODO:

• Make initialization key/values with defaults
• Calibration