Category: Computers

Single Board Computers and Amateur Radio

Single Board Computers and Amateur Radio

Since the advent of the home computer there have been radio amateurs who have explored the possibilities of using computers in their shacks and as computer technology and software have developed it has allowed more amateurs to be able to use a computer in their shack even if it is just for logging and looking up call signs on QRZ.Com.

In recent years there has been a new kid on the block, the Single Board Computer or SBC which as the name suggests has all the necessary components required mounted on a single board whereas on a desk top computer the various components are attached to a central circuit board via cables.

There are a number of SBC’s available but the one that kicked off this change is the Raspberry Pi SBC, there is a lot of support out there for this SBC and over the past few years they have been featured more and more in articles in Amateur Radio magazines here in the UK and abroad where radio amateurs have used them in their radio related projects.

So what is the Raspberry Pi ?

First and foremost, the Raspberry Pi was a product that was produced to be a fairly cheap way for children to get involved in computing and programming either through education in schools or for use at home and in order to facilitate this further the cost of a Raspberry Pi has always tried to be around the £30 mark. Despite being made to what you might consider to be a tight budget the Raspberry Pi uses the best components available at that time.

Over the years there have been various models of the Raspberry Pi and currently the main model (most powerful) of the Pi is the Raspberry Pi model 3 B+ which can be purchased for around £32 to £34 depending upon where you buy it.

Since its release in 2012 the Raspberry Pi is one of the best-selling computers of all time (number 3 in the rankings according to a recent report that I read). Makers and hackers have since taken up its use in a big way and use it in all manner of smart tech projects and so have radio amateurs. Due to its cheap price several of these little computers can be used at once for various radio applications, consider if you ran two or three separate computers/laptops in your shack then the space required let alone the cost involved would be prohibitive for most people.

Specifications for the Raspberry Pi model 3 B+

  • Broadcom BCM2837B0, Cortex-A53 (ARMv8) 64-bit SoC @ 1.4GHz
  • 1GB LPDDR2 SDRAM
  • 4GHz and 5GHz IEEE 802.11.b/g/n/ac wireless LAN, Bluetooth 4.2, BLE
  • Gigabit Ethernet over USB 2.0 (maximum throughput 300 Mbps)
  • Extended 40-pin GPIO header
  • Full-size HDMI
  • 4 USB 2.0 ports
  • CSI camera port for connecting a Raspberry Pi camera
  • DSI display port for connecting a Raspberry Pi touchscreen display
  • 4-pole stereo output and composite video port
  • Micro SD port for loading your operating system and storing data
  • 5V/2.5A DC power input
  • Power-over-Ethernet (PoE) support (requires separate PoE HAT)

In order to use this single board computer (as with most SBC’s), you will need to connect it to a monitor via the HDMI connector, you will also need a keyboard and mouse, power is provided by the use of an old phone charger with a micro USB connector or an official Raspberry Pi power supply.

The Raspberry Pi does not come with an operating system loaded onto the board so in order to use it you have to load an operating system onto a micro SD card which then plugs into the appropriate Micro SD slot on the Pi. The Raspberry Pi website has various operating systems that are available to download and when it comes to using the computer for amateur radio purposes then fortunately there are amateurs out there who have written software for us to use.

Amateur Radio Uses for SBC’s

About three years ago I bought myself an SDRplay software defined radio. There are various software downloads available for the SDRplay which are supported by Windows, Mac, Linux etc. and one of the computers listed that is supported with compatible software is the Raspberry Pi. I initially used the SDRplay with a windows laptop, I had heard of the Raspberry Pi but at that time I didn’t know anything about them or what they were.

On club night in the spring of 2016 I was sitting next to a couple of members who were discussing creating a D-Star hotspot using a Raspberry Pi, I mentioned that my SDR radio could be operated using a Raspberry Pi, but I didn’t know anything about them. The upshot was that I was lent a Raspberry Pi 2 model B which I had a play around with at home, the only down side for me was that the connection to the internet was via an Ethernet cable and considering my shack is in the front upstairs bedroom and my internet router is downstairs this created a bit of a problem, I didn’t have an Ethernet cable that long and I didn’t really want to go down that path every time that I wanted to connect this computer to the internet.

Doing some research on the internet about the Raspberry Pi I saw that about a month or so earlier a raspberry Pi 3 model B had been released with an increased performance over the Pi 2 and it also had Bluetooth and Wi-Fi connectivity as standard. I decided to buy one but due to the improved connectivity of the new version of Pi it was selling out fast, so I had to trawl through a lot of sites before I found a trader who still had some in stock.

So now I had my own Raspberry Pi and I connected it to my mouse, keyboard and monitor. I found that it was just a computer but in a different form factor (Linux based) and there is quite a lot of software already loaded onto the board. There is software relating to programming and coding and a Libre Office package which (I think) is very similar to Microsoft Office and I now also use it on my Windows laptop.

I downloaded the software for the raspberry pi off the SDRplay website and loaded it onto a micro SD card, connected everything up and I was up and running without any problems at all.

Another SBC that I use is the Latte Panda which does utilise Windows 10 as its operating system and it is downloaded onto the board so basically any software that you would use on a laptop or base home computer can be downloaded onto this SBC.

Since my initial foray into connecting my SDRplay to a Raspberry Pi, I have set up another Pi as an ADSB receiver with a connected dongle which I have running 24/7.

I have also played around using the Raspberry Pi for decoding data modes, namely FT8.

I am continually looking at other amateur radio uses for the  SBC’s that I own and apart from the projects I have outlined they can be used in the following ways; As your main shack computer, for logging, as a WSPR transmitter, for tracking satellites, as a DV Hotspot, as an APRS gate, as a rotator controller or for decoding CW to name just a few applications.

For their cost and size these little computers are great fun to use and are a very cost-effective way of using a computer in the shack and going back to comments made at the beginning of this post I can potentially use four of these little computers at the same time for ham radio.

 

73’s Graham M0GAE