There are numerous different models of the Raspberry Pi. Since the market launch in 2012, the performance of the mini computers has developed significantly. The following versions of the Raspberry Pi are among the best
known (most recent versions are mentioned first, as of late 2020):
Raspberry Pi 3 Model B
Raspberry Pi 2 Model B
Raspberry Pi Zero
Raspberry Pi 1 Model B and B +
Raspberry Pi 1 model A and A +
In the first generation of devices, ARM CPUs with a clock frequency of 700 megahertz were still installed (ARMv6/32 bit). In the latest model, the Raspberry Pi 3 Model B, an ARMv8 quad-core processor (64 bit) with a
clock frequency of 1.2 gigahertz does its job. It has a gigabyte of SDRAM memory. The Raspberry Pi Zero is particularly compact and inexpensive. With its board width of just over 30 instead of 56 millimeters, it occupies a
special position among the models. The Pi Zero lacks an Ethernet and FBAS interface. HDMI and USB sockets have been reduced to the mini HDMI and micro USB format.
Expand the Raspberry Pi
The most important features of the Raspberry Pi include its almost unlimited expansion options. The Raspberry Pi can be easily expanded via its integrated USB interface. Devices such as USB cameras, USB memory sticks or USB
WLAN and USB surf sticks can be connected there. The only requirement for use is the availability of a suitable driver that is supported by the operating system. In addition to the expansion options via USB interface, expansion
boards for the GPIO pin header are available. There is even a separate extension standard for this. It is the HAT standard (Hardware Attached on the Top), which defines, among other things, the dimensions and shape of the
expansion boards. This allows a board according to the HAT standard to be attached and attached to the Raspberry Pi. The drivers required to operate the board can be stored in the EEPROMs on the expansion card. This allows
integration without manual driver integration or configuration.