An introduction to�Raspberry Pi
Neil Goldstein – W2NDG
HRU 2023
Who is W2NDG?
Overview
What is it?
The Raspberry Pi, is simply, a computer.
A small, inexpensive computer.
It has the same components of a larger system, or equivalents. Input-Output, Memory, Storage, Audio, Video, and more.
What isn’t it?
The Raspberry Pi is not the same thing as an Arduino board, or other microcontroller specific systems.
It does have a GPIO bus for performing many Arduino-like functions, so in some ways it’s the best of both worlds
Integrates many components that are usually separate from the CPU into ONE PACKAGE.
Used in many compact, and appliance-like products. Your phone has a SOC. Low-end laptops like a ChromeBook have a SOC.
SOC (System On a Chip)
RISC stands for Reduced Instruction Set Computing. As compared to CISC (Complex..) It is more efficient. A 1GHz RISC is much more capable than a 1GHz INTEL Pentium
This is why when you look at ARM processors like the ARM Cortex-A53 in the current Pi 3 you cannot compare apples to apples with speed, and RAM.
RISC vs CISC
Some RISC-based Products:
iPhone
Android Phones
Raspberry Pi
PlayStation 3 CELL Processor
PowerPC
History
Released to the public in February 2012
Main goals were accessibility and education
Much like the BBC MICRO computer from ACORN in Britain in the Eighties
Insanely popular at first. Supply was tight.
There have been several major revisions since release.
Original Pi Model B
History
BBC has since produced an education-oriented board for learning called MICRO BIT
Now in Version 2. Great little learning tool, and worth checking out for learning programming and microcontrollers
micro:bit V2
Models : Original
Raspberry Pi (1)
Model A
Original Pi Model A
Others: -Newer Model A
-Compute Board
700 MHz Single Core
256 M RAM
1 USB Port
NO Ethernet
HDMI
Composite
Analog Audio
SD Card (Full)
Models : Original
Raspberry Pi (1)
Model B
Original Pi Model B
700 MHz Single Core
512 M RAM
(256 early models)
2 USB Ports
Ethernet
HDMI
Composite
Analog Audio
SD Card (Full)
Models : Original PLUS
Raspberry Pi (1)
Model B+
Pi Model B+
700 MHz Single Core
512 M RAM
4 USB Ports
Ethernet
HDMI
Composite
Analog Audio
(Composite and Audio integrated in one jack)
SD Card (Micro)
Models : Pi 2
Raspberry Pi 2
Model B
Pi 2 Model B
900 MHz Quad Core
1 GB RAM
4 USB Ports
Ethernet
HDMI
Composite
Analog Audio
(Composite and Audio integrated in one jack)
SD Card (Micro)
More GPIO Pins
Models : Pi 3
Raspberry Pi 3
Model B
Pi 3 Model B
1.2 GHz Quad Core
(64 Bit)
1 GB RAM
4 USB Ports
Ethernet
HDMI
Composite
Analog Audio
WiFi
Bluetooth
(Composite and Audio integrated in one jack)
SD Card (Micro)
Models : Pi 3
Raspberry Pi 3
Model B+
Pi 3 Model B
1.4 GHz Quad Core
(64 Bit)
1 GB RAM
4 USB Ports
Ethernet
HDMI
Composite
Analog Audio
WiFi (Dual Band)
Bluetooth (Updated)
(Composite and Audio integrated in one jack)
SD Card (Micro)
POE
Models : Pi 4
Raspberry Pi 4
Model B
Pi 4 Model B
1.5 GHz Quad Core
(64 Bit) ARM V8
2, 4, or 8 GB RAM
2 USB2 Ports 2 USB3
Gigabit Ethernet
2 X Micro HDMI
Composite
Analog Audio
WiFi (Dual Band)
Bluetooth (Updated)
(Composite and Audio integrated in one jack)
SD Card (Micro)
POE
USB C Power
Models : Pi ZERO
Raspberry Pi Zero
Pi Zero
1 GHz Single Core
512 M RAM
1 Micro USB Port
(needs OTG Adapter)
Mini HDMI
Analog Audio (through GPIO)
SD Card (Micro)
TINY – and $5
Models : Pi ZEROW
Raspberry Pi Zero W
Pi Zero
1 GHz Single Core
512 M RAM
1 Micro USB Port
(needs OTG Adapter)
Mini HDMI
Analog Audio (through GPIO)
SD Card (Micro)
Wifi
Bluetooth
TINY – and $5
Models : Pi ZERO2 W
Raspberry Pi Zero2 W
Pi Zero
1GHz quad-core 64-bit
512 M RAM
1 Micro USB Port
(needs OTG Adapter)
Mini HDMI
Analog Audio (through GPIO)
SD Card (Micro)
Wifi (2.4 Ghz b/g/n)
(In new shielded enclosure)
Bluetooth 4.2
STILL TINY – and $15
Models : Pi 400
Raspberry Pi 400
Pi 400 vs Pi 4
1.8 GHz Quad Core
(64 Bit) ARM V8
4 GB RAM
2 USB2 Ports 2 USB3
Gigabit Ethernet
2 X Micro HDMI
WiFi (Dual Band)
Bluetooth (Updated)
No composite or audio jack
SD Card (Micro)
POE
USB C Power
Horizontal GPIO
Built-In Keyboard
Cooling (improved)
Models : Pi PICO
Raspberry Pi Pico
Models : Pi COMPUTE MODULE 4
Raspberry Pi Compute Module 4
Layout : Previous Model
RaspberryPi 3 Layout
Layout : Current Model
RaspberryPi 4 Layout Changes
New Form Factor (new cases required)
Operating Systems
OFFICIAL OPERATING SYSTEM IMAGES
As mentioned before, because of the Pi’s ARM architecture, only programs compiled to run in an ARM environment are available. Not everything compiles well for ARM, but there are lots of choices.
In particular, the WINE layer for running Windows programs will not work. At least not directly. There have been attempts to make an X86 emulation layer for the Pi, but so far, they have not worked very well. If you want to investigate, look at QEMU or BOCHS.
What are the limitations?
What about Windows??
Originally, we saw the IOT version of Windows for Pi. That seems to no longer be around, but several users have managed to hack the ARM version of Windows 10 to run on a Pi. There is, in fact, an active community supporting methods to get Windows running on the Pi. This is still not supported by Microsoft though, and still has many issues.
And Android?
Broadcom has not opened up Android support for it’s SOC used in the Pi. Some of the Pi alternatives support it. There is an experimental Android distro though called Lineage OS that works marginally.
Frequently I hear that the Cranberry Deluxe Mini, or <insert generic name here> is so much better than the Raspberry Pi from people. There are definitely applications where there are viable alternatives. A great example being the KiwiSDR project which relies on one of the Beagle Boards.
The Other Contenders
Stability
We don’t see the Raspberry Pi project disappearing any time soon. Some of the others already have. CHIP being the most visible failure. There are SO MANY. Just Google: Alternatives to Raspberry Pi
Support
You can’t beat the popularity of the Pi. It might not be the most powerful choice for a specific task, but the community support is endless, as well as the huge choice in add-ons and accessories.
Supply Chain Issues (ugh!)
Inovato Quadra
It’s basically a computer, and will do almost anything that a computer would do.
It won’t be as fast as a modern desktop, although the Model 4 is pretty quick, especially the 4GB version. Finally approaching usable desktop speed
You have the addition of the GPIO bus for controlling and sensing the world around you
What Can I Do With it?
Small Desktop Computer
Media Center
Music Player
Weather Station
Robotics
Web Enabled Controller
Education
Remote Camera
Terminal – Thin Client
Gaming
Kiosks
Small Servers
Ham Radio
For now, we are limited to LINUX programs that run on ARM processors. That’s FLDIGI and few rig control apps, as well as some SDR applications. There are also linking, APRS, and Packet applications.
Ham Radio Uses
ADS-B Airplane Tracking
Remote SDR Server
SDR Radio (Pi 3 & 4 Only)
Digital Radio Hotspot
Echolink node
APRS
WSPR
Antenna and Rotator Control
TNC
Spectrum Monitor
PSK31 Terminal (and others)
Rig Control (RigPi)
Transmitter (more on that….)
Transmitting Directly from Pi
GPIO Pins can be modulated at a high enough frequency to transmit RF
Transmitting Directly from Pi
The Pi FM Project originally demonstrated this by transmitting music over FM stereo.
Later, others modified the theory to get AM, FM, SSB, and digital modes.
The output is not very clean and obviously very low power.
There are projects to make all kinds of transmitters which work as long as you filter the output, including low power fox hunt transmitters.
Transmitting Directly from Pi
WSPR Pi is a project from TAPR (Tucson Amateur Packet Radio). It combines the filters and amplifier needed to clean up an HF signal into a neat little board.
Amateur
There’s a way to create a transceiver using this board (with some minor changes) and a RTL-SDR dongle in either direct-sampling mode or with an upconverter. You’ll probably want an amp too. GTCSDR
Remote SDR
Both the WEBSDR project (websdr.org) and OPENWebRX (openwebrx.de) work with Raspberry pi hardware for simple single-band remote SDR using RTL-SDR dongles, or other simple SDR hardware
APRS
TNC-Pi is a special version of TNC-X designed to interface directly with the Raspberry Pi computer. It can connect to the Pi either via the Pi's serial port, or via the I2C protocol.
Hotspots
Make your own Digital Radio hotspot! You can order simplex and duplex add-on cards for a Raspberry Pi to turn it into a fully functioning D.R. hotspot running Pi-Star. This one was a kit and ran about $42 + a Raspberry Pi Zero W ($5) Works for all popular modes
Digital Modes
We now have enough speed from the Pi4 to create a reliable digital mode terminal.
Use a Pi4, and one of the new dedicated digital mode radios from QRPGuys, CRKits (Adam Rong), or Midnight Design Solutions
Ham Clock
Here’s a project called Ham Clock from WB0OEW. Active display of all sorts of useful information for the Ham Radio operator
RigPi
This is an example of a commercial product that grew out of an open source Pi project. Currently sold by MFJ. The RigPi
Future / Current Projects
There are many projects for the Pi that have come and gone, and some just around the corner. Here’s one that is current on CrowdSupply:
The CaribouLite Rpi HAT
https://www.crowdsupply.com/cariboulabs/cariboulite-rpi-hat
Dual Channel SDR 30MHz – 6GHz
Future / Current Projects
The sBITX from Ashar Farhan
Early release: “Developers Edition”
Future / Current Projects
The sBITX from Ashar Farhan
Early release: “Developers Edition”
Future / Current Projects
Microcontroller Based Radios:
(tr)u-SDX, T-41, QCX, QDX, (QSX)
More Info
There is a Groups.io group called Raspberry_Pi_4-Ham_RADIO
Just Googling “Raspberry Pi Ham Radio” will turn up mountains of information. Searching on Amazon brings up a couple of books on the subject
More Info
W3DJS Has put together a Ham Radio Specific Raspberry Pi Image
Join the Groups.IO group Ham-Pi for more information
Now in V2, it contains almost any Ham Radio app you could need.
https://sourceforge.net/projects/hampi/
Also look at the io group Raspberry Pi for Ham Radio.
�What’s Your Message?
�HRU 2021
As usual I will post this set of slides on my website, as well as a list of links to resources by early next week.
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Email: neil@neilgoldstein.com