Over the air (OTA) updates with the ESP32 are easy
Updating the firmware on an ESP32 over the air (OTA) sounds like a daunting task, but it’s actually quite straightforward. It’s particularly useful if you ha...
Posts by Year
2024
Reading NMEA data with the NEO-6M GPS module and ESP32
At a glance I’m building a GPS tracker for a project, and I wanted to get familiar with this NEO module before I add it to several other components, so I d...
Writing to an SD card with the ESP32
At a glance I bought an SD card reader module to use in another project, to track GPS data, but before adding it into that project, I wanted something simp...
The StreamObserver often used with gRPC streaming, is not thread safe!
I’ve been working with gRPC recently, in particular we had a bi-directional streaming API, whereby once a streaming connection is established, both the clien...
Getting started with a TFT display on an ESP32
At a glance I bought a small TFT display from Temu to be used in a project, but I wanted to test it out first. The display is a 1.8” TFT with a resolution ...
Building a cheap door alarm with an ESP32 and AWS IoT
A few years ago I had a shed built on my property, well perhaps a barn is a better description. Whilst I live in a good area, I’m always concious of security...
How I passed the Confluent Certified Developer for Apache Kafka
After working with Kafka for about a year, I decided to take the Confluent Certified Developer for Apache Kafka exam as a way to help fill in any gaps in the...
2023
Its so easy to setup a raspberry pi now
I may be late to the party, but I’ve just dusted off my ancient Pi 3 and Zero W, having not touched them for years, and have been pleasantly surprised at how...
How I passed 3 Azure certifications in a week
During the depths of winter this year, I decided to set myself a challenge, my performance review was coming up in 1 month, could I achieve 3 Azure fundament...
How I passed the 3 AWS associate exams the first time (and the cloud practitioner!)
I recently passed the SysOps associate exam so I’ve collected “the three” as it’s sometimes know (well, 4 if you include the cloud practitioner). Here’s a fe...
2021
How to setup Google Analytics on your Jekyll Github Pages site
Having setup Google Analytics on my website and Android apps many moons ago, I was surprised how easy it was to setup on Jekyll, there was no messing around ...
Spring annotations not working? Common gotcha in Spring
There’s a very common gotcha with Spring annotations, it’s caught me out in the past, and is certainly one of the things that I check when reviewing pull req...
Migrating from Wordpress to Github pages
I’ve had this website going since being a university student in the mid 2000s, it started off as a static html web page that I maintained myself (hey, I was ...
2020
Raspberry Pi torrent box with VPN, a guide that actually works
In this post I’m going to show you how to setup a torrent box (transmission) on a raspberry pi, that sits on a VPN so your privacy is protected. If the VPN d...
2019
Welcome to Jekyll!
You’ll find this post in your _posts directory. Go ahead and edit it and re-build the site to see your changes. You can rebuild the site in many different wa...
2018
BME280 BMP280 on Wemos Lolin32 with Mongoose OS
The weekend IoT warrior is back again!
Building a water tank sensor using ESP32, JSN SR04T sensor, Mongoose OS and AWS IoT
There’ll be quite a lot going on in this post, I’ve had a crash course in Mongoose OS the past few weeks so this serves as a brain dump!
Convert JSON to YAML in one command
I’ve been playing around with AWS CloudFormation recently, which supports both JSON and YAML. I prefer to use YAML, but a lot of the examples I was looking a...
Getting started with the Mongoose OS and ESP32, an easy tutorial
This year, my goal is to learn as much as I can about IoT and AWS, they go well together and a $10 ESP32 board and a few dollars on the AWS account is a grea...
Listing devices on your local network
Plugged my ancient Raspberry Pi in to my router (yeah the original, that doesn’t have on board wifi) and wanted to SSH into it, found this command to easily ...
Exporting data from Enphase APIs
I bought an Enphase solar powered system in early 2017, one of the major appeals of the Enphase brand was that is has developer APIs, so I could track my sys...
2015
A quick delve into Docker
The problem
Backing up wordpress automatically
I’ve had some difficulties getting the BackWPup plugin to work, it seems that you can’t backup everything in one job as the script takes too long to run and ...
Pig Latin parsing CSV files with quoted commas
In the not too distant past, I was working on a BigData engagement using Apache Pig. I took CSV parsing for granted and expected it to just work, however if ...
2014
Getting your head around the Couchbase SyncGateway
I like Couchbase. One of the things that really appeals to me is the sync gateway. As a mobile developer I often find that the apps I’m developing are just i...
Service first using JAX-WS
There are two ways for developing services using JAX-WS, service first, and contract first. Service first means you would typically write the implementation ...
Grails based survey system, the android app
Some time back I wrote an article describing the roosearch system I developed using grails. This is the second part, the android client, please checkout the ...
Changing the hostname on your raspberry pi
By default, the hostname on a raspberry pi installation will be “raspberrypi”, which is great if you just have the one pi.
Getting to grips with Grails, building a survey management system
Sometime in late 2012 I was discussing dissertation project ideas with my girlfriend, as she was coming up to her final year of a computing bachelors. The us...
Project Euler, problem 4, palindromes
Problem 4:
Project Euler, problem 3, largest prime factor
Problem 3 :
BrickPi Lego robot takes its first steps!
A little while back I wrote a post about creating a python script to control a brickpi robot, now that I actually have the brickpi components, motors and cab...
2013
Installing a new Java JDK on a Mac
Updating Java on a Mac is easy, it’s just a case of installing a new JDK and recreating the symbolic link that is used to point to the current JDK.
Project Euler, problem 2, fibonacci sequence
Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be: 1, 2, 3, 5...
Why all Java devs should at least consider Groovy and Spock for testing
As a developer, testing is very important. Some developers have the mindset of “Meh, I write code, testing is a QAs job”, which is pretty poor. It’s much bet...
Project Euler, problem 1, multiple factors
If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23. Find the sum of all t...
An intro to Node.js, building a URL shortener
Node has been on my todo list of things to investigate for a little while now, whilst I don’t have much background in javascript, after constantly hearing ab...
Robots! Part 2, the android client
Continuing on from my previous post, I’ve created an android client that I can use to send commands to my python server.
Robots! (part 1)
Inspired by the android controlled lego robots I saw at DroidCon UK this year, and with difficulty finding a use for my raspberry pi, I’ve decided to have a ...
Selecting partial elements of mongo db documents
By default, when you find documents on mongo it returns the entire document, similar to what SELECT * FROM TABLE; would do in a relational world.
What I thought of “Instant Android Fragmentation Management How-to”
I was recently contacted by the marketing team from Packt Publishing and asked if I could write a review for one of their new ebooks, so here it is!
A few little tweaks to automate Android instrumentation testing via Robotium & Maven
Having recently revived an android project I haven’t opened in close to 6 months, I was left scratching my head as to why I couldn’t run any of my integratio...
Bootstrapping a Grails application to prepopulate data on startup
I’ve been dabbling in a little Grails recently, and I found it quite frustrating having to re-enter some sample data everytime I restarted my application, in...
Deploying a grails application to Cloudbees
I spent much of last weekend experimenting with the grails framework, so I wanted to deploy what I had in the cloud. Theres a big tutorial on the IntelliJ ID...
Override the toString on your domain classes so they display as something useful
If you’re finding that your domain objects are not being displayed in a readable manner, chances are its because they haven’t been told to. This is often the...
2012
How I passed the SCJP / OCPJP
After procrastinating for many years (4 to be precise), I finally sat and passed the SCJP exam. The exam itself wasn’t particularly difficult, but theres a l...
Not posted in a while, busy busy busy!
Hi folks,
Continue and break, with and without labels, for the SCJP
Looping constructs are very useful in any programming language, however they can be come particularly complex when you have a variety of nested loops and you...
Interfaces, declaring and implementing
Another bite-size SCJP blog post, this time we’ll tackle interfaces.
Polymorphism, a little overview with code samples
Polymorphism basically means that one thing can take many forms, and this is particularly useful for programmers, as it allows us to treat similar types of o...
Inheritance, some examples for SCJP study
Inheritance is a practice of one thing extending another. So you can more specific subclasses of a class. Inheritance is available in most programming langua...
Encapsulation; shielding state via the use of accessors
Encapsulation is a fantastic OOP concept of being able to shield class state via the use of accessor methods.
Overloading in Java, what it is and how you can use it, along with some examples
There are times when developing, when you need to do similar behaviour but with differing input arguments, for example you may have a method that prints some...
Basics of the switch statement in Java
If statements are great, but sometimes they are just not very practical when you have to test for more than a handful of conditions, have a look at this very...
Deploying the android libraries into your maven repository
Maven is a fantastic build tool, and a great addition to anyone developing on the android platform, however one of the first hurdles that people often stumbl...
Stop Mac OS X creating hidden files when using the tar command
Last week I found something quite frustrating with the tar command on Mac OS X, it likes to put hidden files into archives when you tar them up, it doesn’t g...
What I thought of the SyncNorwich Lightning Talks
I’d always been under the impression that the IT scene in East Anglia was a little quiet, and more so the further you got away from London, but I was quite p...
Change the display name of your iOS apps
Decided on a long name for your application when you created it, but are now fed up of seeing it display like this on the home screen?
Recursively deleting .svn directories
Messing around with your subversion directories and fed up of the .svn hidden folders laying around? If you try and checkin some directories that contain a ....
How to show hidden files in the Mac OS Finder
Frustrated, that I recently couldn’t find my maven settings.xml file because the Mac OS X Finder doesn’t show hidden files by default, I found that the follo...
Extracting out your AsyncTasks into separate classes makes your code cleaner
If you’re an android developer, chances are you’ve used an Async task more than once. As your apps develop, grow, and become more complex, theres a high chan...
Deploying artefacts into your CloudBees maven repositories.
If you’re like me, and have a fair few hobby projects on the go at any one time, you’re may want to take advantage of some of the free cloud services that ar...
Sending Tweets from your iOS5 app, easy!
Sending a tweet from your iOS application could not be any easier, Apple and Twitter really were looking out for their developers.
Improving Tesseract OCR results on the iOS platform
If you’ve found yourself using Tesseract on the iOS platform, and you’re scratching your head as to why the OCR results are so terribly incorrect, you might ...
Tesseract OCR on Android is easier if you Maven-ise it, works on Windows too…
I’ve spent the past few months working on an android application that involves an element of OCR capability, its been quite a painful journey so this is my a...
How to install any application on the emulator
I’ve been developing an app recently that relies on being able to navigate and browse for images on the phone, which is all well and good when testing on a d...
Using special characters in a linux sed command without having to escaping them
I came across a brilliant little feature of the linux sed command today that I wasn’t aware of, and thought it was well worth posting up about.
Asserting for a Toast message using Robolectric
I’ve recently put together a few proof of concept applications, and since they’re “rough and ready” applications, a lot of the functionality is actually mock...
A second app to launch; Agile Planning Poker
After launching my first application onto the market back in March 2011, and amassing somewhere in the region of 15,000 downloads since it’s launch, I was ea...
How to add a splash screen to your android application in under 5 minutes
Adding a splash screen to your application is a quick and easy way to make it look more well rounded, complete, and more professional, it can also serve as a...
Converting dp to pixels in android
Sometimes in android you have to deal with pixels, which can often be awkward, such as view.setPadding(int, int, int, int). Obviously this is not ideal as pi...
2011
Top 10 Techie things I want to achieve in 2012
I’m not the type of person that gets bored easily, I’ve always got many things to keep me amused, mostly side projects at home. I’m a firm believer, that if ...
SMS text messaging simulation on android
As part of an application I’m currently developing, I need to be able to interogate incoming SMS messages. Since I’ll be developing against the emulator init...
Automating android application signing and zipaligning with maven
This is something that has had me tearing my hair out for a few days now, I was pretty much border-line braveheart-ing my screen….
String concatenation operator
The string concatenation operator is a bit like a hedgehog, it looks cute and sweet, but try to grab hold of it quickly and you’ll soon know about it…
The instanceof Operator
The instanceof operator is a great way for checking if a reference variable is of a given type, in other words, does it pass the IS-A inheritance test. Ask y...
Compound Assignment Operators
There are various compound assignment operators, however it is only necessary to know the 4 basic compound assignment operators for the exam, being as follow...
Static members
Statics are a rather strange beast, they belong to no instance of a class, they have no fixed abode, other than their class..
Local Variables, as far as the SCJP is concerned
Local variables are variables that are declared locally, funny that eh? This one should be nice and easy, lets have a look at a quick example :
Other modifiers, for members
We’ve already touched upon various modifiers, for classes (both access and non-access), but there are also some more modifiers for members, as detailed here.
Class Modifiers (non-access)
In addition to class access modifiers, classes can also be marked with non-access modifiers. These modifiers imply rules on a class, but are not necessarily ...
Class Access Modifiers
Class access modifiers define who can see the class, you use it on a daily basis, have a look at the following :
Varargs, for those times when you are not sure how many parameters you will have
As of Java 5, methods are now able to accept from 0 to many arguments. Sounds confusing, but you could actually be using it already without knowing, how abou...
Coupling and Cohesion, what you need to know for SCJP…
Coupling and cohesion are two terms that often get mixed up, however they are actually really simple concepts, and the bonus is, they don’t just apply to Jav...
How to send an email from your Android application
If you’re like me, you’ll certainly like to hear feedback on your applications out there on the market, and what better method than via a direct email link.
Publishing your app to the Android Market, a noobs guide
Hola a todos! Its been a little while since I last posted, mostly because I’ve been busy getting my first app in a state thats good enough to be published, i...
How to place your ads at the bottom of your screen in Android
So you’ve setup some ads using AdMob or AdWhirl for your android application, and you’re having a hard time getting the ad to appear at the bottom of your sc...
Android; A really easy tutorial on how to use Text To Speech (TTS) and how you can enter text and have it spoken
Hello readers, time for another little android post of mine. I’ve been working hard recently on some voice recognition and TTS work, so figured I’d post up s...
Monetizing your Android apps with AdMob (AdSense), an easy guide
Howdy folks, another nice and easy android guide here. If you’re like me you’re thinking about putting your first application up on the market. It might be a...
Getting started with Git, and GitHub, the noobs guide
I’ve always been a Subversion man myself, but today I took Vaders’ advice and joined the darkside. As part of a tutorial I wrote on here I wanted to host som...
Android and SQLite, a REALLY easy tutorial that anyone can do
Howdy folks! Time for some more android fun. I’ve been meaning to explore some of the SQLite functionality for some time, as I require it in my Cerca de mí a...
Android; How to implement voice recognition, a nice easy tutorial…
I’ve been searching for a simple tutorial on using voice recognition in Android but haven’t had much luck. The Google official documentation provide an examp...
The Conditional (ternary) operator, cleaning up if-else assignments since 1996
The conditional operator, or ternary operator as it is otherwise known is a great way for assigning variables based on boolean tests. For example you may hav...
Android; how to display a map the easy way..
I’m seeing countless questions, literally on a daily basis on StackOverflow regarding using maps on Android. To be honest I’ve never come across these proble...
How to keep checking if port is open, by issuing socket connects
I recently need to check if a particular application is online and listening on a particular set of ports. I figured that the best way to do this was to peri...
Looping in Java, a brief look at the various loops and how they can be applied
One of the great features of any programming language is the ability to repeat blocks of code, sometimes indefinately, sometimes until a certain condition is...
Java; the for-each loop, perfect for fondling collections and arrays
The for loop is great, but is it really that nice when you want to iterate over an array or collection? You’d have to do something like the following :
The do-while loop, always executes at least once…
As I’ve covered in a previous post regarding the while loop, the do-while, often refered to as the do loop is very similar. Lets have a look at the psuedo co...
Using while loops, for when you do not know how long the piece of string is
Just another bitesize SCJP post here, looking at the while loop in Java.
Playing with the For loop in Java
The for loop is an extremely flexible and powerful way of iterating over a code block for a set number of times. Generally speaking, this type of loop is gre...
Binding your buttons to your activity, the easy way!
OK, so you have several buttons on your view, all linked into the same activity. Sounds simple enough, you probably have something that looks like the follow...
Overriding and Overloading, a n00bs explanation
This is easily one of the most confusing concepts to a newbie, but to be honest its relatively simple. The most confusing part is that both start with the le...
Static Imports, how they could and should be used
One of the new features of Java 5 is the static import, its quite simple in nature. You have probably done something like the following many times before :
Declaration Rules in Java
Another one of my short and sweet posts in my SCJP study guide section. This one is quite straightforward, so we’ll keep it quick, since I know you’d much ra...
How to quickly and easily convert a formatted XML into a single line
So you’ve got a nicely formatted XML object, with all your indentation setup so that it is easy to read. However there may come a time when you need that lov...
2010
Android or Standard Java; Mapping your XML onto POJOs easily, and vice versa
I’ve listed this post under Android, but to be honest this could apply to both J2SE and J2EE, its not really specific to Android but it was part of a require...
Android; Continuous integration, all made lovely with Maven
Lets face it, the eclipse ADT plugin is great for getting an android application up and running quickly, but if you want an easier way to get libraries, and ...
Android; how to actually put your applications APK onto a device
OK, so you’ve been developing your “hello world” application in Eclipse for a little while, and now want to actually test it out on a device.
Integrating your wordpress into twitter and facebook, the easy way
I’ve been searching for a viable and easy solution for integrating my wordpress posts into facebook and twitter for some time now, and have finally found an ...
Identifiers and JavaBeans
Identifiers are what we use to identify parts of our code, whether this is a class, method or a variable. There are some ground rules on the names we can giv...
Tutorial; How to call Yahoo! REST web services the easy way!
I’ve got some requirements where I need to call a REST web service from an Android device, so I figured I’d get back to basics, and try to call a REST servic...
Some thoughts and opinions on ITIL v3 Foundation
After recently sitting a course and exam for ITIL v3 Foundation, I thought it would be a good idea to reflect on some of the topics covered while they are fr...
Android; Querying data from your phone book; names, addresses, postcodes, emails etc
One of the more useful features of Android is the ability to obtain data from elements of Android itself, such as the phone book. Your application may requir...
Android; Using intents to refresh tab content
As part of my MeCercana application, I needed to refresh data in some form. My application has 3 tabs, one of the tabs displays contacts from the contacts bo...
Android; Implementing global state; share data between Activities and across your application
If your developing an Android application, chances are you will have multiple activities that perform various tasks. One of my first questions when I was inv...
Converting UK Postcodes to co ordinates to use in Android
If your developing applications on Android, and are looking at using the Maps API, chances are you are going to want to plot items on the map, and in order t...
Incrementing and Decrementing, the operators
The operators for incrementing and decrementing in Java has been irritating me for some time now, just when I think I understand whats going on, I try a mock...
FTP: How to download all files, directories and sub-directories
I’ve recently decided to cancel my hosting package with 1and1, as I don’t really have much use for it any more what with all the freebies Google is dishing o...
Post: Link Permalink
This theme supports link posts, made famous by John Gruber. To use, just add link: http://url-you-want-linked to the post’s YAML front matter and you’re done.
Post: Quote
Only one thing is impossible for God: To find any sense in any copyright law on the planet. Mark Twain
Post: Notice
A notice displays information that explains nearby content. Often used to call attention to a particular detail.
Post: Chat
Abbott: Strange as it may seem, they give ball players nowadays very peculiar names.
Post: Standard
All children, except one, grow up. They soon know that they will grow up, and the way Wendy knew was this. One day when she was two years old she was playing...
Post: Modified Date
This post has been updated and should show a modified date if used in a layout.
2009
JSTL Expressions ignored by Google App Engine, how to fix that..
So, you’ve written a nice J2EE application and have uploaded it onto the GAE only to be upset that your nice variables are displaying as ${contact.firstName}...
Modify your Java web application to run on Google App Engine
So, you have a Java web application that you would like to host somewhere for free, no worries, Google to the rescue. What is Google App Engine? Well to quot...
Setting up a basic Stripes framework
After being introduced to Struts1, Struts2 and SpringMVC at a very early stage in my development career, I was very happy to work on a project with Stripes. ...
Slackware 13.0 Installation : Part 1, pre-install
Slackware, which I like to refer to as “proper linux”, theres no messing around with fancy wizards, this is hardcore linux; and a good cure for insomnia (sec...
Linux from Scratch, an Intro
So, I’ve decided to have a go at linux from scratch, which should satisfy a good headache for the next year or so, possibly longer.