RaspberryPi - Native Node.js extention to interact with an Ultrasonic Sensor.
Initially stand alone extension written in C++. The end goal is to integrate it into raspi-io IO Plugin for johnny-five. Specifically to support the pingRead method of an IO plugin, which can't be implemented using javascript alone and requires native code.
Relevant links:
npm install raspi-sonar
Note that GPIO pins are rated at 3.3v. An ultrasonic sensor like the HC-SR04 outputs 5v on the echo pin which could harm your Raspberry Pi's GPIO pins. Take care to use a voltage divider circuit to lower the voltage from the ECHO pin to the GPIO pin.
var Sonar = require('raspi-sonar').Sonar;
var sonarPin1 = new Sonar(29);
sonarPin1.read(function(duration) {
var distance = 343.0 * duration / 1000000 * .5;
console.log('duration: ' + duration + ' distance: ' + distance + 'm');
});raspi-sonar npm package exposes a single class called Sonar. The Sonar class has a single public method that takes the wiringPi pin number as an argument. If you installed wiringPi (which will automatically be installed when you install the raspi-sonar package), you can check the which pin number to use by typing the command gpio readall. The output for a Raspberry Pi B+ would look like the below diagram. Note the 'wPi' columns.
The MIT License (MIT)
Copyright (c) 2016 Seshi Chemudugunta
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