Sonar

The Sonar class constructs objects that represent a single analog or I2C Sonar sensor attached to the physical board. This class works with:

• Maxbotix Analog Sonar

  • Any

• Devantech I2C Sonar

  • SRF02
  • SRF08
  • SRF10

This list will continue to be updated as more Sonar devices are confirmed.

Parameters

• pin A String address for the Sonar pin (analog only).

• options An object of property parameters.

<tr>
  <td>freq</td>
  <td>Number</td>
  <td>Milliseconds</td>
  <td>The frequency in ms of data events. Defaults to 25ms</td>
  <td>no</td>
</tr>
<tr>
  <td>threshold</td>
  <td>Number</td>
  <td>Any</td>
  <td>The change threshold (+/- value). Defaults to 1</td>
  <td>no</td>
</tr>

Property Name	Type	Value(s)	Description	Required
pin	Number, String	"A0", "I1", 5 (Any pin on board)	The Number or String address of the pin the sonar is attached to, ie. "A0" or "I1"	yes (for analog)
device	String	"SRF02", "SRF08"	A String model id of a Sonar device (I2C only), ie. "SRF02", "SRF08", "SRF10"	yes (for I2C)

Shape

{ 
  id: A user definable id value. Defaults to a generated uid
  pin: The pin address that the Sonar is attached to
  cm: Value of current reading in centimeters. READONLY
  inches: Value of current reading in inches. READONLY
  value: cm: Value of current reading.
}

Component Initialization

// Create an analog Sonar object:
// 
//   - attached to pin "A0"
//
var sonar = new five.Sonar({
  pin: "A0", 
});

// Create an I2C Sonar object:
// 
//   - use device model "SRF10"

var sonar = new five.Sonar({
  controller: "SRF10"
});

Usage

var five = require("../lib/johnny-five.js");
var board = new five.Board();

board.on("ready", function() {
  var sonar = new five.Sonar("A0");

  sonar.on("data", function() {
    console.log("inches     : " + this.in);
    console.log("centimeters: " + this.cm);
    console.log("-----------------------");
  });
});

API

• within(range[, unit], handler) When value is within the provided range, execute callback.

var sonar = new five.Sonar({
  device: "SRF10"
});

sonar.within([ 5, 10 ], "inches", function() {
  
  // This is called when the sonar detects an object 5-10 inches away

});

Events

• change The "change" event is emitted whenever the value of the sonar changes more then the threshold value allows.

• data The "data" event is fired as frequently as the user defined freq will allow in milliseconds. ("data" replaced the "read" event)