Sonar - lyzadanger/johnny-five GitHub Wiki

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.

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

var sonar = new five.Sonar("A0");

• 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>

// Create an I2C Sonar object: // // - use device model "SRF08" // - emits data events every 250ms // var sonar = new five.Sonar({ device: "SRF08", freq: 250 });

### 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. }

### Usage
```js
var five = require("johnny-five"), 
    board = new five.Board();

board.on("ready", function() {

  // Create a new analog `sonar` hardware instance.
  var sonar = new five.Sonar("A0");

  sonar.on("data", function() {
    console.log( this.cm );
  });
});

• 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

});

• 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)