Fejemis brush unit

Revision as of 15:05, 12 September 2022

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Introduction

The brush unit is controlled by a Teensy 3.2. In addition to the brush it also controls the movement of the front wheel.

The front wheel can lift the brush, to be able to pass cables on the floor and to move when the brush is off.

The front wheel is also a steering wheel, helping the differential drive when turning.

Circuit

The bridge combines different inputs from hardware sources to a single socket-based interface point. Selected interface points are made available as ROS messages and key commands can be received from ROS. The main input and output connections are to the Drive and Front Teensy boards, these connections are protected by a simple checksum, the ';99' part, to avoid false or half messages when powering up. All data items are single lines of text. These data items start with a key and optionally additional parameters. The data item has further a data source associated. Data items can be directed to a destination (data forward). A data item can be requested or updates to a data item can be subscribed. The ini-file can be a set of directed commands, e.g. calibration data or subscription of data from the data sources. All data items can be logged individually with a timestamp.