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First reading with a USB-TTL adapter

You need a module, a USB-TTL adapter whose logic level matches the module (check wiring and power), and a supply for the module.

Option 1: the browser serial monitor​

Open the serial monitor in Chrome or Edge on a desktop computer, pick the model, press Connect serial port. You get the distance, a live chart and a CSV export. Nothing is installed and nothing leaves your computer.

Option 2: Python​

pip install erdi-lrf
erdi-lrf models                                    # list the models and their defaults
erdi-lrf --port COM3 --model LRF22VB stream --count 20      # streaming modules (family B)
erdi-lrf --port COM3 --model LRF3000A1 measure              # polled modules (family A)

Use /dev/ttyUSB0 instead of COM3 on Linux. In code:

from erdi_lrf import ErdiLRF

with ErdiLRF("COM3", "LRF22VB") as lrf:
    for r in lrf.stream():
        print("out of range" if r.out_of_range else f"{r.metres:.3f} m")

The package takes the baud rate, frame length and unit from the model name, so use the exact model.

If nothing arrives​

  1. Swap TX and RX.
  2. Check the baud rate against the model page.
  3. Measure the supply at the module while it is running; a weak supply resets the module.
  4. For family B, remember that frames start on their own. For family A, nothing arrives until you send a command.
  5. Work through field troubleshooting.