Single-board mini computers from the Raspberry Pi series have gained recognition around the world. They are used by both home-type tinkerers and professional designers of programmable electronic devices. In 2019, the latest model appeared on sale - the Raspberry Pi 4B. Compared to previous models, Pi 4B has been equipped with an even more efficient quad-core processor Broadcom BCM2711 clocked at 1,5 GHz of frequency and for the first time, it consists two Micro HDMI outputs for external monitors instead of a single standard A-type HDMI connector. You can use the Raspberry Pi 4B in the same way as a standard PC for internet browsing and office work, as well as a driver for physical devices with electronic and mechanical systems, thanks to the versatile 40-pin GPIO connector. By using the GPIO connector in Raspberry Pi, you can easily create a home automation management centre, electrical drive controller, audiophile D-class amplifier, retro-style gaming machine, remote control apparatus for unmanned vehicles and much more! Sounds marvellous, isn't it? And it's still real to come true - just use the Raspberry Pi HAT hardware extension boards that are GPIO-compatible with Raspberry Pi 4B!