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.

NOTE: The Sonar class is being replaced by the Proximity class, which will support all proximity/ranging sensors.

Parameters

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

• options An object of property parameters.

  Property	Type	Value/Description	Default	Required
  pin	Number, String	Any pin. The Number or String address of the pin the sonar is attached to, ie. “A0” or “I1”		yes (for analog)
  controller	String	“SRF02”, “SRF08”. A String model id of a Sonar device (I2C only), ie. “SRF02”, “SRF08”, “SRF10”		yes (for I2C)
  freq	Number	Milliseconds. The frequency in ms of data events.	25ms	no
  threshold	Number	Any. The change threshold (+/- value).	1	no

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

Maxbotix Analog Sonar

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

I2C Sonar

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

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)