The Raspberry Pi B+ is an update to the original design based on improvements requests by the Raspberry Pi community. As more and more people use Raspberry Pi's for hobby electronics, education and fun, the more users find unexpected limitations to their projects. Such as needing more GPIO pins or finding their Pi doesn't run on batteries quite as long as they need. So the foundation have released an update that will please a lot of Raspberry Pi enthusiasts.
The main improvements on the model B+ compared to the model B version 2 is:
- 40 pin GPIO port instead of 26 pins
- 4 USB ports
- Metal Micro SD port instead of a plastic SD card port
- More efficient power usage. Use 4 USB devices including external hard drives and longer battery life.
- Combined audio and composite video 3.5 jack port
- Improved audio capabilities
The layout of the board has also changed.
- The two USB ports don't overhang the edge of the board so much making the footprint of the board smaller.
- The micro USB power supply port has been moved round next to the HDMI port
- The combined Audio and Composite port is smaller than the old Audio port and is behind the Network port.
- The Camera CSI port and the HDMI port have been moved back to make space for the Audio/Video port
- The power circuit has been re-designed with no prominent capacitor.
- The 4 mounting holes are form a square
The good news is for existing Raspberry Pi model B owners is that you don't need to buy a B+ unless you want to as it uses the same processor and also has 512mb of memory. Though the extra USB ports, GPIO pins and better power usage will be of interest to a lot of current users.
Existing GPIO add-on boards can still be used with the model B+ as the first 26 GPIO pins are still in the same configuration as the model B. If you do have a board that covers the whole of the model B such as the PiFace Digital then you will probably need to use a GPIO port extender to raise the add-on board above the extra USB port. Also existing cases will not fit as the ports have moved about so expect to see some new cases and re-designed GPIO add-on cards going on sale soon.
For more information see the article at RaspberryPi.org