@bytesnz

Jack Farley, Computer Engineer

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  • 6/16/2022

    JS Binary Decoder

    software

    I have recently been dealing with parsing binary data packets from various sources, and have published two NPM libraries from it - binary-decoder and sbd-direct-ip. How's how they came to be.

  • 4/19/2022

    New Zealand Low Power Wide Area Networks

    electronicssoftware

    I have started experimenting with low power wide area networks (LP-WAN) in New Zealand using a u-blox SARA-R410-02B. Here is is what I have experimented with so far.

  • 2/7/2022

    Starting with ESP32

    esp32electronicssoftwaretrap-watch

    I started developing my trap-watch project on an ESP32-CAM using the ESP IDF. Here is the newbie difficulties I ran into.

  • 2/4/2022

    VIM Window Rabbit Hole

    linux

    Developing ESP-IDF components I thought it would be great if I could make a command to open all the files for a component at once. What a rabbit hole it was. Here is how I did it.

  • 1/28/2022

    Parsing Arguments in Bash

    linux

    Making a script parse arugments in Bash took me way too long last time I did it, so here is a nice full example of how to do it using getopt

  • 1/8/2022

    Where's my bait gone?

    electronicsconservationtrap-watch

    I have recently started trapping some introduced predators around my local area and have had baits and pre-feed disappear with nothing to show for it, so I decided to get sparky and see if I could catch the culprit in the act.

  • 3/26/2021

    Bathymetric Contours

    gisgeoserveroceans

    Finally got around to creating a SLD style for GeoServer to display bathymetric contour lines using the GEBCO gridded bathymetric data. Here's how.

    Getting slightly distracted, I noticed bathymetric contour layer we are using for our app doesn't cover one of the areas we are working in.

    I had already downloaded the GEBCO gridded bathymetric data data for creating terrain tiles to use with CesiumJS and imported the TIFF into GeoServer, so I just needed to create the Style to display contours.

    I started off with the very helpful GeoSever docs() on Rendering Transformations, namely the Contour extraction example. After adjusting the Transformation level values to more useful values for us, I tried previewing the map. Lots of lines!

    Style preview showing all the contour lines

    I needed to cut down the data shown on the map for the lower (more zoomed out) levels, so looked into rules and filters and added up two additional <Rule> sections with various levels of.

    The rules produces the following previews

    Style preview showing the very high-level contours on the globe

    Style preview showing medium level contours around Oceania

    Style preview showing full detail contours along the bottom of the North Island and New Zealand

    Below is the style XML. I still need to figure out how to remove the lines produced from the edge of the TIFF image.

    
    <?xml version="1.0" encoding="ISO-8859-1"?>
    <StyledLayerDescriptor version="1.0.0"
      xsi:schemaLocation="http://www.opengis.net/sld StyledLayerDescriptor.xsd"
      xmlns="http://www.opengis.net/sld"
      xmlns:ogc="http://www.opengis.net/ogc"
      xmlns:xlink="http://www.w3.org/1999/xlink"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
      <NamedLayer>
        <Name>contour_dem</Name>
        <UserStyle>
          <Title>Bathymetry Contours</Title>
          <Abstract>Bathymetry contours produced from the GEBCO 15 arc-second gridded bathymetry</Abstract>
          <FeatureTypeStyle>
            <Transformation>
              <ogc:Function name="ras:Contour">
                <ogc:Function name="parameter">
                  <ogc:Literal>data</ogc:Literal>
                </ogc:Function>
                <ogc:Function name="parameter">
                  <ogc:Literal>levels</ogc:Literal>
                  <ogc:Literal>0</ogc:Literal>
                  <ogc:Literal>-100</ogc:Literal>
                  <ogc:Literal>-200</ogc:Literal>
                  <ogc:Literal>-300</ogc:Literal>
                  <ogc:Literal>-400</ogc:Literal>
                  <ogc:Literal>-500</ogc:Literal>
                  <ogc:Literal>-600</ogc:Literal>
                  <ogc:Literal>-700</ogc:Literal>
                  <ogc:Literal>-800</ogc:Literal>
                  <ogc:Literal>-900</ogc:Literal>
                  <ogc:Literal>-1000</ogc:Literal>
                  <ogc:Literal>-1100</ogc:Literal>
                  <ogc:Literal>-1200</ogc:Literal>
                  <ogc:Literal>-1300</ogc:Literal>
                  <ogc:Literal>-1400</ogc:Literal>
                  <ogc:Literal>-1500</ogc:Literal>
                  <ogc:Literal>-1600</ogc:Literal>
                  <ogc:Literal>-1700</ogc:Literal>
                  <ogc:Literal>-1800</ogc:Literal>
                  <ogc:Literal>-1900</ogc:Literal>
                  <ogc:Literal>-2000</ogc:Literal>
                  <ogc:Literal>-3000</ogc:Literal>
                  <ogc:Literal>-4000</ogc:Literal>
                  <ogc:Literal>-5000</ogc:Literal>
                  <ogc:Literal>-6000</ogc:Literal>
                  <ogc:Literal>-7000</ogc:Literal>
                  <ogc:Literal>-8000</ogc:Literal>
                  <ogc:Literal>-9000</ogc:Literal>
                  <ogc:Literal>-10000</ogc:Literal>
                  <ogc:Literal>-11000</ogc:Literal>
                  <ogc:Literal>-12000</ogc:Literal>
                </ogc:Function>
              </ogc:Function>
            </Transformation>
            <Rule>
              <Name>deep_water</Name>
              <Title>Deep Water Contours</Title>
              <MaxScaleDenominator>800000</MaxScaleDenominator>
              <LineSymbolizer>
                <Stroke>
                  <CssParameter name="stroke">#000000</CssParameter>
                  <CssParameter name="stroke-width">1</CssParameter>
                </Stroke>
              </LineSymbolizer>
              <TextSymbolizer>
                <Label>
                  <ogc:PropertyName>value</ogc:PropertyName>
                </Label>
                <Font>
                  <CssParameter name="font-family">Arial</CssParameter>
                  <CssParameter name="font-style">Normal</CssParameter>
                  <CssParameter name="font-size">10</CssParameter>
                </Font>
                <LabelPlacement>
                  <LinePlacement/>
                </LabelPlacement>
                <Halo>
                  <Radius>
                    <ogc:Literal>2</ogc:Literal>
                  </Radius>
                  <Fill>
                    <CssParameter name="fill">#FFFFFF</CssParameter>
                    <CssParameter name="fill-opacity">0.6</CssParameter>
                  </Fill>
                </Halo>
                <Fill>
                  <CssParameter name="fill">#000000</CssParameter>
                </Fill>
                <Priority>2000</Priority>
                <VendorOption name="followLine">true</VendorOption>
                <VendorOption name="repeat">100</VendorOption>
                <VendorOption name="maxDisplacement">50</VendorOption>
                <VendorOption name="maxAngleDelta">30</VendorOption>
              </TextSymbolizer>
            </Rule>
            <Rule>
              <Name>platform_limits</Name>
              <Title>Platform Limit Contours</Title>
              <MaxScaleDenominator>20000000</MaxScaleDenominator>
              <ogc:Filter>
                <ogc:Or>
                  <ogc:PropertyIsEqualTo>
                    <ogc:PropertyName>value</ogc:PropertyName>
                    <ogc:Literal>-100</ogc:Literal>
                  </ogc:PropertyIsEqualTo>
                  <ogc:PropertyIsEqualTo>
                    <ogc:PropertyName>value</ogc:PropertyName>
                    <ogc:Literal>-500</ogc:Literal>
                  </ogc:PropertyIsEqualTo>
                  <ogc:PropertyIsEqualTo>
                    <ogc:PropertyName>value</ogc:PropertyName>
                    <ogc:Literal>-1000</ogc:Literal>
                  </ogc:PropertyIsEqualTo>
                  <ogc:PropertyIsEqualTo>
                    <ogc:PropertyName>value</ogc:PropertyName>
                    <ogc:Literal>-1500</ogc:Literal>
                  </ogc:PropertyIsEqualTo>
                  <ogc:PropertyIsEqualTo>
                    <ogc:PropertyName>value</ogc:PropertyName>
                    <ogc:Literal>-6000</ogc:Literal>
                  </ogc:PropertyIsEqualTo>
                </ogc:Or>
              </ogc:Filter>
              <LineSymbolizer>
                <Stroke>
                  <CssParameter name="stroke">#000000</CssParameter>
                  <CssParameter name="stroke-width">1</CssParameter>
                </Stroke>
              </LineSymbolizer>
              <TextSymbolizer>
                <Label>
                  <ogc:PropertyName>value</ogc:PropertyName>
                </Label>
                <Font>
                  <CssParameter name="font-family">Arial</CssParameter>
                  <CssParameter name="font-style">Normal</CssParameter>
                  <CssParameter name="font-size">10</CssParameter>
                </Font>
                <LabelPlacement>
                  <LinePlacement/>
                </LabelPlacement>
                <Halo>
                  <Radius>
                    <ogc:Literal>2</ogc:Literal>
                  </Radius>
                  <Fill>
                    <CssParameter name="fill">#FFFFFF</CssParameter>
                    <CssParameter name="fill-opacity">0.6</CssParameter>
                  </Fill>
                </Halo>
                <Fill>
                  <CssParameter name="fill">#000000</CssParameter>
                </Fill>
                <Priority>2000</Priority>
                <VendorOption name="followLine">true</VendorOption>
                <VendorOption name="repeat">100</VendorOption>
                <VendorOption name="maxDisplacement">50</VendorOption>
                <VendorOption name="maxAngleDelta">30</VendorOption>
              </TextSymbolizer>
            </Rule>
            <Rule>
              <Name>full</Name>
              <Title>Full Detail Contours</Title>
              <ogc:Filter>
                <ogc:Or>
                  <ogc:PropertyIsEqualTo>
                    <ogc:PropertyName>value</ogc:PropertyName>
                    <ogc:Literal>-1000</ogc:Literal>
                  </ogc:PropertyIsEqualTo>
                  <ogc:PropertyIsEqualTo>
                    <ogc:PropertyName>value</ogc:PropertyName>
                    <ogc:Literal>-6000</ogc:Literal>
                  </ogc:PropertyIsEqualTo>
                </ogc:Or>
              </ogc:Filter>
              <LineSymbolizer>
                <Stroke>
                  <CssParameter name="stroke">#000000</CssParameter>
                  <CssParameter name="stroke-width">1</CssParameter>
                </Stroke>
              </LineSymbolizer>
              <TextSymbolizer>
                <Label>
                  <ogc:PropertyName>value</ogc:PropertyName>
                </Label>
                <Font>
                  <CssParameter name="font-family">Arial</CssParameter>
                  <CssParameter name="font-style">Normal</CssParameter>
                  <CssParameter name="font-size">10</CssParameter>
                </Font>
                <LabelPlacement>
                  <LinePlacement/>
                </LabelPlacement>
                <Halo>
                  <Radius>
                    <ogc:Literal>2</ogc:Literal>
                  </Radius>
                  <Fill>
                    <CssParameter name="fill">#FFFFFF</CssParameter>
                    <CssParameter name="fill-opacity">0.6</CssParameter>
                  </Fill>
                </Halo>
                <Fill>
                  <CssParameter name="fill">#000000</CssParameter>
                </Fill>
                <Priority>2000</Priority>
                <VendorOption name="followLine">true</VendorOption>
                <VendorOption name="repeat">100</VendorOption>
                <VendorOption name="maxDisplacement">50</VendorOption>
                <VendorOption name="maxAngleDelta">30</VendorOption>
              </TextSymbolizer>
            </Rule>
          </FeatureTypeStyle>
        </UserStyle>
      </NamedLayer>
    </StyledLayerDescriptor>
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  • 2/25/2021

    shm That Cache

    yarndockerdevelopment

    I am often trying to find more space on my hard drives and found today my own docker containers wasting space thanks to ! Here's how I fixed it.

  • 2/2/2021

    Blob blob blob blob Stayin' Alive Stayin' Alive

    softwarejavascriptdebuggingmemory

    Upon recently trying Deezer again, I found their web app ate all my memory when running in Firefox, so I decided to see if I could find out why. I got as far as memory-file-data/string and Blobs. Here's how.

  • 12/25/2020

    A new Litter Survey

    softwarelitterlitter-survey

    In a culmination of litter surveys and litter picks, linked data and data exploration, and remoteStorage and ActivityPub, I have created a web-based litter pick/survey app that I hope will allow federated citizen science.

  • 12/13/2020

    Hoe Stream Trash

    litterpi-trash-camlitter-pick

    My latest litter pick target was Hoe Stream and the White Rose Lane Local Nature Reserve. Here's how it went.

  • 11/24/2020

    Release the Beast

    softwaregitlabcirelease

    I just created a Gitlab CI job to create a release with information from a CHANGELOG.md file for some of my projects. Here's how I did it.

  • 9/30/2020

    Gitlab CI Caching

    gitlabcontinuous integration

    I noticed something strange happening during build process during a multi-tasking bug fix. Turns out I was using Gitlab CI's caching incorrectly. I should have been using artifacts. Here's what I saw.

  • 9/21/2020

    Birthday Trash

    litterpi-trash-cam

    As a birthday treat, I took the day off work to try out my electronerised litter picker. Here's how it went.

  • 9/13/2020

    Pi Trash Cam

    raspberry pielectronicslitterpi-trash-cam

    In preparation for a day of litter picking, I finally got round to a project idea - attaching a camera to a litter picker to record it all. Here's what I did.

  • 8/25/2020

    yarn add --dev webdriverio

    first-draftsoftwaretestinggitlab

    I finally started implementing UI testing on first-draft using WebdriverIO. While writing tests was easy, getting the tests running was a little more difficult. Here is how I did it.

  • 8/16/2020

    Hooray! My new blog is live! Based on Sapper, using MongoDB and eventually ActivityPub and ActivityStreams, it will be my federated posting hub to the world.

    softwareblog
  • 8/9/2020

    Removing EXIF Data from Photos

    exifphotos

    Creating this new blog, I wanted to make sure there was no metadata data leaking personal information. Here's how I removed all the metadata tags except the ones I wanted from my photos.

  • 8/9/2020

    tmux List and Reattach

    tmuxbashsoftware

    Using tmux for your terminal multiplexer but want an easy to reattach to a session? Here's a small bash script to do it.

  • 8/8/2020

    Selectable Shell Examples

    markdownsyntaxcss

    Here's how to help your readers save time by making your post's shell commands easy to select and copy - with a simple CSS property.

  • 8/5/2020

    Be Dates You

    mongodbdocker

    Making my new blog, I didn't initially set the published dates to be native dates in the database. Here what I did to change them ...and do all the upgrades I needed.

  • 7/8/2020

    Testing vue components

    softwarevuetestingjavascript

    I recently needed to test that some Vue components were creating the correct HTML. To do this, I decided to create snapshots of Object representations of the rendered HTML.

  • 2/20/2019

    No More Numbers

    javascripthtml5software

    HTML5 number inputs aren't useful, but tel inputs, have all the power

  • 12/21/2018

    A Hacker "Hacked" Me

    securityemailgrep

    I decided to look into the extortion emails I have been getting and wrote a small script to extract the bitcoin addresses that have been used.

  • 12/7/2018

    Mouse Surgery

    pledge to not upgradeelectronics

    As part of my pledge not to upgrade, I decided to repair two of my failing mice instead of replacing them with a brand new model (as tempting as it was). Here's what I did.

  • 10/29/2018

    Danger Danger, Highly Reactive

    vuereactivegraphingdata
  • 9/11/2018

    Switching to SSR

    reactssrreact-loader
  • 8/10/2018

    Clean Docker Registry

    nodedockerconsolejavascript
  • 2/1/2018

    Testing on the Filesystem

    testingjavascript
  • 1/26/2018

    Tag You Are

    javascripttags
  • 1/25/2018

    NaN Got Me

    rubber duck savejavascriptnodejsjson
  • 4/28/2017

    All our app's tabs are belong to us

    angularjavascriptlocalstoragerxjssessionstorage
  • 2/20/2016

    Developing NPM modules

    nodejsnpm
  • 2/20/2016

    Nfa + Nfb or N(f+fa+fb)

    arrayfunctionjavascriptjsperf
  • 10/31/2015

    Photo Layout

    arrangercssgallery hierarchyhtmljavascriptphotostinymcewordpresssoftware
  • 10/31/2015

    Browning Pass HideAway Web Site

    cssgallery hierarchyhtmlwordpress
  • 10/17/2015

    Think Mobile

    mobileweb
  • 10/13/2015

    Pledge to Refuse and Not Buy Bottled Water

    environmentpledges
  • 2/25/2015

    Run PHP run!

    maximum execution timephptrial and error
  • 11/26/2014

    Gallery Hierarchy

    galleryhierarchyphotos
  • 10/3/2014

    Vim and functions

    functionnavigationtagsvim
  • 9/26/2014

    I'm making hierarchies

    hierarchical datahierarchyphp
  • 9/4/2014

    Google Sheets fun

    googlegoogle scriptgoogle sheetsjavascriptsheets
  • 8/13/2014

    Travel Photos

    photo managementphotostravel photos
  • 8/13/2014

    Image managment scripts

    photo managementphotos
  • 7/31/2014

    MeldCE logo

    csshtml5javascriptsvg
  • 4/26/2014

    MoltenDB

    databasemoltendbmongodbnodejs
  • 10/29/2013

    The Expensive Side

    house
  • 9/22/2013

    abcde

    music
  • 7/16/2013

    Energizer Power Plus Rechargeable Batteries

    gadgets
  • 3/4/2013

    USAR FOGTeX

    fogtex
  • 2/21/2013

    Personal Gear Bag

    rescuegear
  • 2/18/2013

    Geocaching Stamp

    stampgeocaching
  • 4/2/2007

    Call Record Presenter

    parserpythonsqliteweb
  • 9/25/2004

    Kimi Ora School

    csshtml
  • 6/25/2004

    All About Catering Web Site

    csshtml
  • 7/26/2003

    Quantum Accounting Web Site

    csshtml
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