General

A general blog entry

Vintage Ekco RCX 'Ekcosprite' - Volume won't turn down to zero

I was working on restoring an old Ekcosprite recently and came across a puzzling problem where the tubes all tested fine, as did all the components (many were replaced and new)... but I could not shut the voume fully off.  It took some experimenting and head-scratching - and finally a little Googling to figure it out.

Ekcosprite RCX

Typewriter effect in Python

I was looking for a way to get a typewriter effect on the console, and this is what I came up with - hopefully its useful to someone.  I'm not sure if the end="" will function in Python 2.x

 

Arduino Traffic Light Example

So here is an example I wrote for some students.  This simulates traffic lights with one arduino for each direction and uses a random timer to decide which device turns green first - then the devices control each other (each can have different times but the code is the same on both devices.

 

Murphy (F&P) Service Information for various models

Fisher and PaykelRecently I aquired a large folder full of service information for the NZ designed and built 'Murphy' range of radios, TV's and grams from the 60's and 70's.  This brand was produced by Fisher and Paykel - who's main claim to fame these days is whiteware.

Philco 'Alabama' - NZ Model

Philco 401 'Alabama' Front

Philco 401 'Alabama'

Philco 401 'Alabama' Rear

Android App Inventor - Using "List From CSV ROW" to populate a ListPicker (Drop-down List)

Recently I was asked to teach a class on Android Programming with the end-goal of them writing a simple game. As they were young students with experience in Scratch (http://scratch.mit.edu/) I used App Inventor (http://ai2.appinventor.mit.edu/) because of its similarities - and because teaching Java / Android would have taken too long.

Christchurch House / Section For Sale Map (now New Zealand wide)

UPDATE: I've modified it to be full screen and work New Zealand wide:

http://essentialtech.co.nz/sites/default/files/propertymap/index.php

It still hasn't got OAuth set up yet, so if you get no results, its probably used all its queries for that hour... try again soon.

 

First play with an Arduino Uno and an HC-SR04 Ultrasonic Distance Module

Well, I caved.  I've avoided the mass stampede to the Ardiono camp for a long time, because PICs did everything I wanted and I liked them... but I got offered one of these fandangled Uno things to play with - and I've gotta say its actually pretty neat.  

I can really see why they have taken off, given the ease of programming them (although I suspect that some of the 'glossing over' that the Arduino IDE provides will actually create a whole generation of bad embedded programmers - it really lets you get away with murder compared to a standard C implementation).

Hash Tables - How cool are they...

I wrote this after finishing my degree... partly because I wanted to see if I could and partly to brush up on my coding skills (which had taken a back seat to my cramming for exams skills).   We'd studied hash tables back in 1st year, but that was the last time I'd had much to do with them.

The idea is that you can store anything using the value you are storing to generate the location you store it in - which means you can do the same calculation you did to store it in order to find it.

Bubblesort - it has a cool name, so it must be good... right?

Well, its been a while since I did any algorithm stuff, but I decided to give myself a refresher in sorting since, unlike Barack Obama, I still like Bubblesort (oops, did I just say that out loud?).  I like it because it has a cool name, and because it was the first sorting method I ever learned, and because for many years it was the only one I knew.