The following are some important specifications that may be useful while selecting this board for your robots:

• Speed of the board: The speed of the ARM processor in Raspberry Pi boards ranges from 700 MHz to 1.2 GHz. These boards are suitable for running an OS and building robotics applications on top of it. We can perform processor-intensive tasks such as image processing on the board. Don't pick this board if you have multiple image-processing applications and other tasks for the robot. They won't properly run on the board. It can freeze the entire system too. This board is perfectly suited for a single robotics application. The latest board, the Raspberry Pi 3, can offer you better performance for robotics applications.
• Memory: The RAM of the board ranges from 256 MB to 1 GB. If the robot application involves a lot of data processing, it may need a good amount of RAM. So for an image processing application, we should select a board with a large RAM size.
• GPIO: The main feature of Raspberry Pi boards is they have dedicated GPIO pins. The GPIO pins have multiple functions, such as I2C, UART, SPI, and PWM. We can't interface an analog sensor with the Pi because there are no inbuilt ADC pins. The GPIO pins are 3.3V compatible, so to interface with TTL logic, we may need a level shifter or voltage divider circuit. For interfacing analog sensors, we may need to interface an external ADC to the Raspberry Pi. The board has a maximum of 40 GPIO pins.
• Power rating: The Raspberry Pi works on 5V, which can take up to 2A current during operation. It will be good if you can provide this rating for the RPi. The RPi can even work from a computer USB port, but the power rating can vary according to the processing. So to be safe, it will be good if we can provide a 5V/2A rating.
• Cost: This is one of the most important criteria while choosing an RPi board. The price range of RPi boards is from 19 USD to 40 USD. You can choose the latest and most expensive board, the Raspberry Pi 3, to get maximum performance. The selection of board will depend on your robotics application.