This turned into a surprisingly tricky project… I have a signalink as my main audio interface box to my radios. It’s basically a USB sound card that connects to the data port of my radios and lets me use digital modes. It also has a couple of knobs to control levels. It’s great, I love it, but as it costs about €130 I wasn’t going to bu another one just for the convenience of not having to move cables around when I want to use it on a different radio.
When querying objects in django the simplest way is to use the filter() query.
If we have a set of systems for example and we want to filter out those that have a SPARC architecture we could do:
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>>> System.objects.filter(architecture="sparc") |
And if we wanted to narrow that down to only sparc machines that use NIS for name resolution we could do:
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System.objects.filter(architecture="sparc").filter(name_resolution="NIS") |
But that is narrowing down the selection. It’s an AND. What were asking for is systems that are a SPARC _AND_ use NIS. And although we can use exclude() to reject some results it’s still and AND operation. What about an OR query?
What if we wanted to select systems that had either a T5 or a T7 processor? Then we need Q queries.
Q queries take the same form of argument as filter() & exclude() etc. but can be combined using OR operators. Here’s the Q query for our model that looks at the cpu_implementation for T5 or T7:
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Q(sysconfig__icontains="T7") | Q(sysconfig__icontains="t5") |
To build our query we just use this Q expression in a filter:
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from django.db.models import Q System.objects.filter(Q(sysconfig__icontains="T7")|Q(sysconfig__icontains="t5")) |
From time to time the International Space station transmits Slow Scan TV (SSTV) images as it passes overhead. These are relatively simple to receive and decode and sometimes you can get a downloadable certificate for decoding them.
An evolving notes-to-self type post…
The ISS has two digipeaters. One on 145.825 MHz and another on 437.550 MHz. The 2m being easier to use, as you don’t really need to account for doppler is the most popular. Though the 70cm was in widespread use when the 2m went offline a couple of years back.
Continue reading APRS with the International Space Station (ISS)While messing about with WSJT-X I noticed that it recommends setting the the mode to Data/Pkt if the radio supports it. My radio, a Yaesu FT-450D, does. But it didn’t work. Thus began a couple of hours down the rabbit hole of serial connections…
Continue reading Setting the DATA mode in Omnirig to use USER-USB for Yaesu RadiosYep still at this after 25 years…
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__ The Realm of the / / -, , ,, __ // || ) || || -\~,\=\ // %||---) /'\\ ,._-_=||= ||/\\ _-_ ,._-_ \\/\\ --=_\=---//= %||---, || || || || || || || \\ || || || -_ =/ \/ //\/ %|| / || || || || || || ||/ || || || _,~/ |_ _|\, |, / \\,/ \\, \\, \\ |/ \\,/ \\, \\ \\ __ ,/_/ \' | `/_ -_- --% _/ //\\ / | | |\_ <* The AberMUD at Ludd *> /(\ _\________/ (,_,)` _-_- ,, , J(\_/ \ /, ' _ || || ,)\/ v \ | || \\ / \\ ||/\\ =||= _-_, / Y ( Y | /J %|| || || || || || || ||_. (7 | \ | '/ \ || || || || || || || % || '| ( /\_______\_ _Y_ \ ( -__,\\ \\_-| \\ |/ \\, ,-_- 'Y \ / \ 7 \ / \ \ / \ _/ ',) ( / ) / | / ( ) '----` '~( ) / __/ i J / / Address: aber.ludd.ltu.se 6715 \ / \ \ | | _/ / aber.dynalias.com 6715 | | )_\_ )_\_/__\/ Mail to: aber@ludd.ltu.se /_\ |___\ |___\ WWW: http://www.ludd.ltu.se/mud/aber (___) -anna Press <Return> to continue... |
Prompted by Michael’s effort at acquiring NOAA Weather Images I thought I’d see what other telemetry or data was easily and publicly available from satellites. Sever satellites operate amateur radio transponders and you can listen in on QSOs, but some also allow you obtain satellite and experiment telemetry.
My first attempt was to get the telemetry from Funcube-1 (AO-73).
Continue reading Funcube Satellite TelemetryWindows 10 comes with a very handy Windows Subsystem for Linux. This lets you set up a linux environment (Ubuntu/SuSE/Redhat etc.) and run linux commands, use linux utilities, and interact with the windows filesystem.
What it doesn’t let you do however is run graphical applications.
Continue reading Running Graphical Linux/X programs on Windows 10‘Summits on the Air’ is a great way to operate an amateur radio station in a portable environment. In Ireland there are plenty of summits, of varying difficulty, to choose from. And you will nearly always manage to make contacts, especially if you can spot yourself on the sotawatch cluster, as people around the world really want to work you.
However, setting up a station, particularly for High Frequency, get’s you noticed. It can involve having a mast about 7m high and 20m of an inverted V dipole hanging from it! This invites attention from hillwalkers – especially if you fly a SOTA flag from the mast!
I’ve produced this leaflet to give out to such curious members of the public who come over for a chat. It’s mainly for Ireland but can easily be adapted for other counties and covers the basics of Summits On The Air.
A while ago I was writing a tool in python to communicate with a sensor on an Arduino. The idea was to have a class for the Arduino that would hold the connection and handle the reading and writing to the serial port. However that way I needed to have the object maintain the connection and the open COM port (this was on windows), but this meant that I could not have multiple objects. Why? Because you can only have one connection to a COM port. The solution – use a Singleton design pattern.
Continue reading Python: Creating a singleton (to control an Arduino)