Author: luke

  • Performance Counters in GNU Radio

    Trunk Recorder is designed around a set of recorders that tune to an active transmission and start recording. When nothing is happening, they pause. This has worked really well, but I sometimes have issues with parts of a previous call getting stuck in all of the buffers between blocks in the GNU Radio flowgraph. This […]

  • Community Created Podcasts

    Well, OpenMHz now has a Podcast! OpenMHz is the website I created that makes it easy for folks to share the recordings of Public Safety radio systems that they capturing using my Trunk Recorder program. I recently added a feature that lets people take a collection of interesting calls and group them together into an […]

  • LibUHD & GNU Radio version mismatches

    I ran into a ver mismatch with @EttusResearch UHD libraries. For Ubuntu 22.04, they moved to ver 4.3. @gnuradio has gnuradio_uhd built against libuhd ver 4.1 in their repo though. The solution was to downgrade libuhd and force libuhd to be 4.1: sudo apt install libuhd-dev=

  • Ubuntu 22.04: Headless Remote Desktop

    Getting Remote Desktop sharing to work on Ubuntu is a real pain. It looks like it has something to do with the screen sharing service starting up before the user has logged in and having the keyring being still locked. Changing from having my user automatically login to using a TimedLogin atleast allow for me […]

  • Building a battery cable for the Arduino Nicla

    The Arduino Nicla is a nice little dev board series. They have managed to cram a ton on them… but it has meant sacrificing the battery connector. Most of the dev boards from Sparkfun and Adafruit have a JST PH connector… as do most of the common LiPo batteries out. The Nicla boards however have […]

  • Photographing all the planes!

    So I put together a system that automatically photographs all of the airplanes that fly over my house. I tweeted about it and things exploded a little on Hacker News. So I thought it could be helpful for folks if I go through some of the details. This story starts about 4 years ago, when […]

  • Wrestling WNYC’s Audiogram Generator

    The Public Radio station, WNYC, released a really nice audiogram generates. Audiograms are those short videos that are created for an audio clip, that show a waveform. Video is easy to share on a lot of social platforms and turning the audio into a video also makes it a little more engaging. WNYC’s tool is […]

  • Note to future self

    If the Int16 PCM audio you are trying to send from an Arduino over serial sounds really blown out… you have an endian problem. Further note: Serial.write() doesn’t like sending 32kb in a single call.

  • My 7yo made a $99 in-app purchase and Apple is refusing a refund!

    With COVID-19, both the kids have been spending a lot of time on iPads. I let my 7 year old son use my iPad and we added his fingerprint so he could log in easier and I could still keep using a long device password. This setup was working great until I got a receipt […]

  • Pretty Graphs from Twilio Narrowband

    I just got my hands on the Twilio Narrowband dev kit… and it is a sweet piece of kit. It is centered around a small Arduino compatible board that has a lot of Seeed connectors. Most importantly it also has a cellular modem built in that is a designed to work with T-Mobile’s nationwide narrowband […]