character fix

I had really strange characters in the ```printDetails()``` on Arduino Serial monitor on MacOS as shown here:
![screen shot 2014-10-14 at 21 57 03](https://cloud.githubusercontent.com/assets/727711/4635741/b397b78c-53dc-11e4-9b98-de64085fef6d.png)

After applying the patch (replacing 0-Byte with a Ring-Bell-but-do-nothing-Byte) the text is shown correctly.

![screen shot 2014-10-14 at 21 58 20](https://cloud.githubusercontent.com/assets/727711/4635783/24e8900a-53dd-11e4-8576-5418f61b72e7.png)