feat: Add Promise-based API

README.md

@@ -10,13 +10,15 @@ $ npm install i2c
 
 ## Usage
 
-```javascript
+### Callback API
 
-var i2c = require('i2c');
-var address = 0x18;
-var wire = new i2c(address, {device: '/dev/i2c-1'}); // point to your i2c address, debug provides REPL interface
+```javascript
+const i2c = require('i2c');
+const address = 0x18;
+const wire = new i2c(address, { device: '/dev/i2c-1' });
 
-wire.scan(function(err, data) {
+wire.scan((err, data) => {
+  if (err) throw err;
   // result contains an array of addresses
 });
 
@@ -44,8 +46,32 @@ wire.write([byte0, byte1], function(err) {});
 wire.read(length, function(err, res) {
   // result contains a buffer of bytes
 });
+````
+
+### Promise API
+
+```javascript
+const i2c = require('i2c');
+const wire = new i2c(0x18, { device: '/dev/i2c-1' });
+
+(async () => {
+  try {
+    const devices = await wire.scanAsync();
+    console.log('Devices found:', devices);
+
+    await wire.writeByteAsync(0x01);
+    await wire.writeBytesAsync(0x02, Buffer.from([0x03, 0x04]));
+
+    const byte = await wire.readByteAsync();
+    console.log('Byte read:', byte);
 
+    const bytes = await wire.readBytesAsync(0x03, 2);
+    console.log('Bytes read:', bytes);
 
+  } catch (err) {
+    console.error('Error:', err);
+  }
+})();
 ````
 
 ## Raspberry Pi Setup

lib/i2c.js

@@ -124,21 +124,99 @@ class i2c extends EventEmitter {
     });
   }
 
-  stream(cmd, len, delay) {
-    if (delay == null) delay = 100;
+  stream(cmd, len, delay = 100) {
     this.setAddress(this.address);
-    wire.readBlock(cmd, len, delay, (err, data) => {
-      if (err) {
-        this.emit('error', err);
-      } else {
-        this.emit('data', {
-          address: this.address,
-          data: data,
-          cmd: cmd,
-          length: len,
-          timestamp: Date.now()
-        });
-      }
+
+    const intervalId = setInterval(() => {
+      this.readBytes(cmd, len, (err, data) => {
+        if (err) {
+          this.emit('error', err);
+        } else {
+          this.emit('data', {
+            address: this.address,
+            data,
+            cmd,
+            length: len,
+            timestamp: Date.now()
+          });
+        }
+      });
+    }, delay);
+
+    return () => {
+      clearInterval(intervalId);
+    };
+  }
+
+  scanAsync() {
+    return new Promise((resolve, reject) => {
+      this.scan((err, data) => {
+        if (err) return reject(err);
+        resolve(data);
+      });
+    });
+  }
+
+  openAsync(device) {
+    return new Promise((resolve, reject) => {
+      this.open(device, (err) => {
+        if (err) return reject(err);
+        resolve();
+      });
+    });
+  }
+
+  writeAsync(buf) {
+    return new Promise((resolve, reject) => {
+      this.write(buf, (err) => {
+        if (err) return reject(err);
+        resolve();
+      });
+    });
+  }
+
+  writeByteAsync(byte) {
+    return new Promise((resolve, reject) => {
+      this.writeByte(byte, (err) => {
+        if (err) return reject(err);
+        resolve();
+      });
+    });
+  }
+
+  writeBytesAsync(cmd, buf) {
+    return new Promise((resolve, reject) => {
+      this.writeBytes(cmd, buf, (err) => {
+        if (err) return reject(err);
+        resolve();
+      });
+    });
+  }
+
+  readAsync(len) {
+    return new Promise((resolve, reject) => {
+      this.read(len, (err, data) => {
+        if (err) return reject(err);
+        resolve(data);
+      });
+    });
+  }
+
+  readByteAsync() {
+    return new Promise((resolve, reject) => {
+      this.readByte((err, data) => {
+        if (err) return reject(err);
+        resolve(data);
+      });
+    });
+  }
+
+  readBytesAsync(cmd, len) {
+    return new Promise((resolve, reject) => {
+      this.readBytes(cmd, len, (err, data) => {
+        if (err) return reject(err);
+        resolve(data);
+      });
     });
   }
 }