properly handle STRING_DATA responses

mgcrea · Jul 31, 2013 · 1f5db9f · 1f5db9f
1 parent 483188c
commit 1f5db9f
Showing 1 changed file with 9 additions and 1 deletion.
diff --git a/lib/firmata.js b/lib/firmata.js
@@ -236,7 +236,14 @@ SYSEX_RESPONSE[I2C_REPLY] = function(board) {
  */
 
 SYSEX_RESPONSE[STRING_DATA] = function(board) {
-    var string = new Buffer(board.currentBuffer.slice(2, -1)).toString('utf8').replace(/\0/g, '');
+    var bytes = board.currentBuffer.slice(2, -1);
+    var data = new Buffer(bytes.length / 2);
+    for (var i = 0, length = bytes.length; i < length; i += 2) {
+        var code = (bytes[i] & 0x7F) | ((bytes[i + 1] & 0x7F) << 7);
+        // debug('<-%s:%d-%d', code, bytes[i] & 0x7F, (bytes[i + 1] & 0x7F) << 7);
+        data[i / 2] = code;
+    }
+    var string = data.toString('utf8');
     debug('receiving a %d-sized string="%s"', string.length, string);
     board.emit('string', string);
 };
@@ -557,6 +564,7 @@ Board.prototype.sendString = function(string) {
     data.push(START_SYSEX);
     data.push(STRING_DATA);
     for (var i = 0, length = bytes.length; i < length; i++) {
+        // debug('->%s:%d,%d', bytes[i], bytes[i] & 0x7F, (bytes[i] >> 7) & 0x7F)
         data.push(bytes[i] & 0x7F);
         data.push((bytes[i] >> 7) & 0x7F);
     }