Building something with robotics, or any project that doesn’t need Ethernet networking? The lightweight, low-power Raspberry Pi A+ might be a great fit. Smaller and lighter than the Raspberry Pi B+, on the A+ the mounting holes are in the same place as the B+, making swapping a B+ for an A+ really easy. The A+, as the B+, is compatible with the new Hardware Attached on Top (HAT) standard for Raspberry Pi add-on boards - it has the same improved GPIO (General Purpose Input/Output) as the B+. The outline of a Model A+ and a HAT board is identical, making an A+ with a HAT expansion board a sleek stack.The design is based around a Broadcom BCM2835 SoC, which includes an ARM1176JZF-S 700 MHz processor and VideoCore IV GPU. Smaller, thinner (only 12mm, limited by the low-profile USB port) and even less power-hungry than the B+, the A+ is considerably cheaper. What's been reduced from the B+ to the A+: one USB port, 256MB RAM and no Ethernet port otherwise electrically identical to the B+ Raspberry Pi A+ Hilights: benefits from the B+’s improved power chain microSD card for booting and long-term storage powered via the USB data ports Raspberry Pi typically uses Linux kernel based operating systems. The Raspberry Pi does not come with a real-time clock; it cannot keep track of the time of day when not powered on. As alternatives, a program running on the Pi can get the time from a network time server or user input at boot time. A real-time clock (such as the DS1307) with battery backup can be added via the I²C interface.