Distance IR Bricklet¶

Features¶

• Measures distances up to 150cm with IR light
• Sensor can be changed
• Output in 1mm steps (12bit resolution)

Description¶

The Distance IR Bricklet can be used to extend the features of Bricks by the capability to measure distances. Sharp analog infrared proximity sensors can be attached to the Bricklet. After configuring the attached sensor you can read out the measured distance in millimeters. With configurable events it is possible to react on changing distances without polling.

Infrared sensors with different distance ranges are available in the shop:

• Infrared Sensor 4-30cm GP2Y0A41SK0F
• Infrared Sensor 10-80cm GP2Y0A21YK0F
• Infrared Sensor 20-150cm GP2Y0A02YK0F

Typically these types of sensors are used in robotics to measure distances for mapping or localization purposes. But you can also use this sensors in other applications, such as a finding out if a door is opened or closed.

Technical Specifications¶

* without cable and sensor

Resources¶

• GP2Y0A41SK0F datasheet (Download)
• GP2Y0A21YK0F datasheet (Download)
• GP2Y0A02YK0F datasheet (Download)
• Schematic (Download)
• Outline and drilling plan (Download)
• Source code and design files (Download)
• 3D model (View online | Download: STEP, FreeCAD)

Test your Distance IR Bricklet¶

To test a Distance IR 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 Distance IR Bricklet to a Brick with a Bricklet Cable (see picture below).

If you connect the Brick to the PC over USB, you should see a new tab named "Distance IR Bricklet" in the Brick Viewer after a moment. Select this tab. If everything went as expected you can now see the measured distance of the sensor, the output voltage of the IR distance sensor and a graph that shows the distance over time. In the image below we slowly moved a hand away from the sensor and to the sensor again.

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

Configure Infrared Sensor¶

The supported infrared sensors simply produce an output voltage based on the measured distance. This voltage is measured by the ADC of the connected Brick. To compute the corresponding distance to this voltage a voltage/distance mapping is needed. This mapping specific to the selected sensor type is stored on the Distance IR Bricklet. If you want to use an IR distance sensor not directly supported by us, you have to calibrate this voltage/distance mapping yourself.

Case¶

A laser-cut case for the Distance IR Bricklet is available.

The assembly is easiest if you follow the following steps:

• Screw spacers to the Bricklet,
• screw bottom plate to bottom spacers,
• build up side plates,
• plug side plates into bottom plate and
• screw top plate to top spacers.

Below you can see an exploded assembly drawing of the Distance IR Bricklet case:

Hint: There is a protective film on both sides of the plates, you have to remove it before assembly.

Programming Interface¶

See Programming Interface for a detailed description.

FAQ¶