Raspberry Pi Field Computer

The Raspberry Pi is a low cost but very effective platform, for off grid computing, or off grid communications. On this page you’ll find various tutorials, helping to build a Raspberry Pi, which is more effective off grid. We will also show you various examples using the raspberry pi for off-grid communications. This first video goes through my thinking and strategy towards a Raspberry Pi for ham radio and off grid Communications.


The previous video titled Ultimate Raspberry Pi build for ham radio, we discussed the strategy an off grid Raspberry Pi field computer, for portable ham radio field communications. In the following video, we’re taking that Raspberry Pi field computer to Lapland just above the Arctic Circle, to put the Raspberry Pi powered portable ham radio station, to the test.

Unfortunately it’s not possible to test the Raspberry Pi field computer, without putting the entire portable ham radio Field Station to the test. This adds the necessary context, when demonstrating off-grid Communications in the field with the Raspberry Pi. That means we’re going to test the Raspberry Pi field computer, the qrp go kit, the effectiveness of a raspberry pi JS8Call combintion for off grid ham radio communications, the shelter, heat source, do some cooking, as well as all the things that go into amateur radio field communications in winter, and above the Arctic Circle.


In addition to information on this page, there’s also a plethora of information about the Raspberry Pi, posted on oh8stn.org.



Tutorials

GPS for Time and Coordinates. The first tutorial I published was adding a GPS as a Time reference, for the Raspberry Pi. In this video I take you through using a low-cost u-blox GPS, configuring it doesn’t ntp reference, to set the time on your Raspberry Pi.


Until recently, rig control over wifi network has been a challenge. Recently, John N0JDS broke me down and made me take another look at the FLRig developments. I was happily surprised to find the FT-891 almost fully supported. This means complete touchscreen control over my VNC client. The UI is still suffering, but its totally useable.

Screen sharing over wifi is another benefit of integration of the raspberry pi with our amateur radios. In the following post, we can see my Yaesu FT-891 and raspberry pi, being remotely accessed by 3 different mobile devices, while in use as a desktop.


RTC Install and configuration. The next in more recent tutorial was adding a real time clock, to the Raspberry Pi. One of the ways the manufacturers of the Raspberry Pi keep costs down, it’s by omitting components which aren’t necessary for efficient operation. This leaves the end user responsible for adding components to the Raspberry Pi, allowing it to meet the needs of their particular project. In practice I didn’t need the real time clock since the GPS worked flawlessly however. If it’s important to have a redundancy plan, in case GPS access for some reason was denied. It was also wise to have a redundancy plan for what could be a very real possibility, where both internet and GPS satellites were inaccessible. In this scenario, we would rely on the Raspberry Pi real time clock. In this video we install, configure, then field test the Raspberry Pi, using amateur radio data Communications on HF. The field test was completely off-grid.


WinLink and PSKMail email are important tools in the ham radio and preparedness communications communities. In this post, you can see PAT WinLink running on my raspberry pi. It appers the project has been abandoned, but it is a workable solution for the raspberry pi powered amateur radio station.


Is it possible to run two unique audio interfaces on the Raspberry Pi, on two seperate apps e.g. FLDigi & Dire Wolf? Answer, absolutely! The raspberry pi 4b is a powerful platform. With adequate cooling, the RPi 4 can easily run two different apps, with two unique audio streams, cat control, … provided the apps are running on seperate workspaces.


In the field

In this video, I take the Raspberry Pi to the field near the Arctic Circle. The goal was to understand the possibility of using a Raspberry Pi, to power a data mode, portable ham radio station in the field. It is a rather Antiquated video. It does show where we came from, and what we were trying to achieve.


Hardware solutions

Over the past couple of years, we’ve tried a few different Hardware Solutions to get the Raspberry Pi off grid. The PiJuice hat was the first. Unfortunately it kind of created just as many problems as it solved. Like many of the solutions we see on this page, they need some time to mature.

NW Digital Radio DRAWS: http://oh8stn.org/blog/2018/11/18/digi-mode-ham-radio-hat-for-raspberry-pi/

DRAWS Hat. NW Digital Radio calls it a Digital Radio Amateur WorkStation Board for the Raspberry Pi. I think Digital Radio Amateur Workstation System would be more cool, but i’ll take it. I was pretty stoked about this board when it came out. The belief was, integrating the Raspberry Pi with a field radio will be easier than ever. Fewer cables, no cable mess, and a clean installation. The hat integrates a GPS, Real-Time clock, dual audio interfaces, and external power regulation. If ever configured correctly, it will solve lots of problems.

Some operators seem to have been able to make it work. I on the other hand was never happy with the support, setup complexity, or the performance on HF digital modes. I’m hoping this was just a matter of letting the product mature, before I get back to it. I stopped working with the product after being incredibly frustrated with all these things. I haven’t given up, but they’re certainly should be an easier way to deploy this device for the end user.

Here are the two videos I did on the draws hat. I’ll come back to it, once it matures.

PiJuice Hat TBD


The PiJuice HAT is a clever idea. It allows you to manage the power of your raspberry pi in off grid applications. I purchased the PiJuice HAT because I wanted to power my raspberry pi externally with the same 12 volts power supply, used by my radios. The PiJuice HAT has an input voltage limitation of 10 volts. That limitation can be overcome with a buck converter. A buck converter will allow us to charge the PiJuice hat externally, from standard solar panels and wind turbines, which normally put out 16-27 volts.
If you’re going to power this device with USB, it’s absolutely perfect how it is. If you’re going to power it from an external power source which is more than 10 volts DC, you’ll need to do the buck converter hack.
Either way though, it’s not a deal-breaker.

The entire Ham Radio with a Raspberry Pi playlist:

Mentioned in the latest video

AmRRon Setup Scripts for Raspberry Pi
https://gitlab.com/amrron/setup-scripts

Buck converters
– USA: https://amzn.to/2QRn8Tu
– UK/EU: https://amzn.to/34qUtZe

Raspberry Pi Enclosure
USA: https://amzn.to/2KVNOyC
UK/EU: https://amzn.to/2Ole0oy

Sabrent USB Audio adapter.
– USA: https://amzn.to/34oeIHc
– UK&EU: https://amzn.to/2KWDmXP

Ublox USB GPS.
– USA: https://amzn.to/35CrIJi
– UK/EU: https://amzn.to/2DjQm5C

Data cables for Yaesu Data port:
– USA: https://ebay.to/2sl34yD
– EU/UK: https://ebay.to/37Bytgh

73, Julian #oh8stn