# Modules Reference: Optical Flow (Driver)

# thoneflow

Source: drivers/optical_flow/thoneflow (opens new window)

# Description

Serial bus driver for the ThoneFlow-3901U optical flow sensor.

Most boards are configured to enable/start the driver on a specified UART using the SENS_TFLOW_CFG parameter.

Setup/usage information: https://docs.px4.io/main/en/sensor/pmw3901.html#thone-thoneflow-3901u

# Examples

Attempt to start driver on a specified serial device.

thoneflow start -d /dev/ttyS1

Stop driver

thoneflow stop

# Usage

thoneflow <command> [arguments...]
   start         Start driver
     -d <val>    Serial device

   stop          Stop driver

   info          Print driver information