Line Bricklet¶

Features¶

• Measures the reflectivity of a surface

• Can be used to detect/follow lines

• Can be used to measure distances of ca. 0-10mm

Description¶

The Line Bricklet can extend Bricks by a reflective optical sensor. The sensor consists of an infrared emitter and a phototransistor. Output of the sensor is the reflectivity of a surface.

The reflectivity value can be used to detect and follow lines (e.g. a black line has a different reflectivity then a white background). The Line Bricklet can also be used to measure the distance to a surface, since the received light decreases with increased distance.

Technical Specifications¶

Resources¶

• CNY70 datasheet (Download)

• Schematic (Download)

• Outline and drilling plan (Download)

• Source code and design files (Download)

Test your Line Bricklet¶

To test a Line Bricklet you need to have Brick Daemon and Brick Viewer installed. Brick Daemon acts as a proxy between the USB interface of the Bricks and the API bindings. Brick Viewer connects to Brick Daemon. It helps to figure out basic information about the connected Bricks and Bricklets and allows to test them.

Connect the Line Bricklet to a Brick with a Bricklet Cable.

If you connect the Brick to the PC over USB, you should see a new tab named "Line Bricklet" in the Brick Viewer after a moment. Select this tab. If everything went as expected you can now see the currently measured reflectivity. To test it you can for example move the Bricklet over a white paper with black stripes on it.

After this test you can go on with writing your own application. See the Programming Interface section for the API of the Line Bricklet and examples in different programming languages.

Mounting of the Line Bricklet¶

To be used as a line detector the Bricklet has to be mounted with a fixed distance to the line. The mounting distance depends on the reflectiveness of the line and the underground. It can be found out by trial and error.

There is a mounting Plate available for the Line Bricklet in the shop which simplifies the mounting. It consists of a mounting plate with fixed distance:

And a mounting plate with configurable distance:

Programming Interface¶

See Programming Interface for a detailed description.