GreySensor

Digital grey sensor array module for XRobot.

This module reads runtime-configurable digital GPIO channels in the order provided by the application layer, converts them into a compact line-tracking sample, and publishes raw state, active state, weighted position, line-loss state, and position memory through a LibXR topic.

The module stays independent from board-level pin names. The board or User layer registers GPIO aliases, then passes those alias strings in channel_names.

Required Hardware

• grey_sensor_gpio_0
• grey_sensor_gpio_1
• grey_sensor_gpio_2
• grey_sensor_gpio_3
• grey_sensor_gpio_4
• grey_sensor_gpio_5
• grey_sensor_gpio_6
• grey_sensor_gpio_7

The GPIO names are constructor arguments, so projects may use other hardware aliases and channel counts up to GreySensor::MAX_CHANNEL_COUNT.

Constructor Arguments

• channel_names: GPIO alias list ordered from left to right
• active_low: default false
• topic_name: default "grey_sensor"
• publish_period_ms: default 10

Published Topics

• topic_name: GreySensor::Sample, including raw / active masks, changed mask, active count, weighted position, remembered position, lost-line side, lost-line count, and sequence number

XRobot Configuration Example

- id: grey_sensor
  name: GreySensor
  constructor_args:
    channel_names:
      - "grey_sensor_gpio_0"
      - "grey_sensor_gpio_1"
      - "grey_sensor_gpio_2"
      - "grey_sensor_gpio_3"
      - "grey_sensor_gpio_4"
      - "grey_sensor_gpio_5"
      - "grey_sensor_gpio_6"
      - "grey_sensor_gpio_7"
    active_low: false
    topic_name: "grey_sensor"
    publish_period_ms: 10