Add Promise-Based API

README.md

@@ -47,6 +47,38 @@ wire.read(length, function(err, res) {
 
 
 ````
+## Usage with async/await
+
+```javascript
+const i2c = require('i2c');
+const address = 0x18;
+const wire = new i2c(address, {device: '/dev/i2c-1'});
+
+(async () => {
+  try {
+    const data = await wire.scanAsync();
+    // result contains an array of addresses
+
+    await wire.writeByteAsync(byte);
+
+    await wire.writeBytesAsync(command, [byte0, byte1]);
+
+    const byte = await wire.readByteAsync();
+    // result is single byte
+
+    const bytes = await wire.readBytesAsync(command, length);
+    // result contains a buffer of bytes
+
+    // plain read/write
+    await wire.writeAsync([byte0, byte1]);
+
+    const buffer = await wire.readAsync(length);
+    // result contains a buffer of bytes
+  } catch (err) {
+    // handle errors
+  }
+})();
+```
 
 ## Raspberry Pi Setup
 

lib/i2c.js

@@ -1,5 +1,6 @@
 const wire = require('../build/Release/i2c');
 const { EventEmitter } = require('events');
+const { promisify } = require('util');
 const tick = setImmediate || process.nextTick;
 
 class i2c extends EventEmitter {
@@ -36,6 +37,15 @@ class i2c extends EventEmitter {
         this.setAddress(this.address);
       }
     });
+
+    this.scanAsync = promisify(this.scan).bind(this);
+    this.openAsync = promisify(this.open).bind(this);
+    this.writeAsync = promisify(this.write).bind(this);
+    this.writeByteAsync = promisify(this.writeByte).bind(this);
+    this.writeBytesAsync = promisify(this.writeBytes).bind(this);
+    this.readAsync = promisify(this.read).bind(this);
+    this.readByteAsync = promisify(this.readByte).bind(this);
+    this.readBytesAsync = promisify(this.readBytes).bind(this);
   }
 
   scan(callback) {