Orange Unit: A Person-Centered Launch
4B: Meet the Microcomputer
Background Knowledge Probe
- While looking through the list of toolkit items found in this textbook’s Introduction, what was the first thing that came to mind when you saw it included a Raspberry Pi? What inspired those thoughts regarding the Pi?
- When you now compare and contrast a Raspberry Pi with your daily use computers, what are your current thoughts? Why have or haven’t they changed?
- What design choices and design objectives might have inspired the Raspberry Pi’s layout function, look, and feel?
Technical Introduction
As an aside, I was one of the fortunate kids who, back in the mid-70s, began learning how to code computers to use them to do things I valued. In this video below, I highlight some of this history, recounting my work with a teletype machine and acoustical modem to connect to a server, a punch card interface with that server, and programming with a Commodore 64 desktop computer.
The Components of the Raspberry Pi
The Raspberry Pi computer used throughout this book is built using a reduced instruction set computing (RISC) architecture known as ARM. This is because RISC-based architectures require fewer than complex instruction set computing (CISC) architectures, such as those used in most desktop and laptop computers.
As a result, this has also opened up new computing opportunities, such as systems-on-chips (SoC) that bring together memory, input/output controllers, processors, radios, etc., into a single integrated circuit. The outcome is typically the lowering of costs, power consumption, heat dissipation, and potentially environmental impacts.
Below you can see Fritzing diagrams of both the Raspberry Pi 3 and Raspberry Pi 4 computers.
Start by taking a few minutes to look over the hardware list for the Raspberry Pi 3 Model B, the earliest model of the third-generation Raspberry Pi.[2] This includes:
- A Broadcom BCM2837 system-on-chip (the largest of the black, square integrated circuits on the printed circuit board). Built into this SoC is:
- Quad-core 1.2 GHz 64-bit ARM cortex A53 CPU
- Full HD 1080p, H.264 Video Encode/Decode, 400MHz VideoCore IV Graphical Co-Processor Unit
- 1 GB SDRAM
- 512 KB cache memory
- One of the many smaller integrated circuits is a Broadcom BCM43438 chip that provides:
- Wireless LAN
- Bluetooth 4.1
- Next to pin 1 of the GPIO, just above the “Made In” label, is the chip antenna for wireless LAN and Bluetooth signals.
- Just off from the USB ports, you’ll find the SMSC LAN9514 chip, providing the controller for 10/100 Ethernet connectivity and four USB channels.
- A variety of I/O connectors, sockets, and ports, including:
- 4 USB 2 ports
- Full size HDMI port
- Micro SD port for loading an operating system and storing data
- 10/100 Ethernet port
- 4 pole stereo output and composite video port
- 40-pin extended GPIO connector
- Camera Serial Interface Type 2 (CSI) camera port, used to connect CSI-type cameras with the SoC chip