The Raspberry Pi Foundation announced a
big small upgrade to is Pi lineup today. The A+ is a sub 2.5-inch square (65mmx55mm vs. 86mm for the B+ and A) and uses less power and adds some nice improvements:
- More GPIO. The GPIO header has grown to 40 pins. The Model A+ is compatible with the HAT standard for add-on boards.
- Micro SD. The old friction-fit SD card socket has been replaced with a much nicer push-push micro SD version.
- Better audio. The audio circuit incorporates a dedicated low-noise power supply.
The big deal is the even cheaper $20 price point, $15 less than either of the previous models.
Two great intro videos and a comparison chart below: