House 4 Hack

Please note the course has been post-poned and a new date will be announced soon

Overview

This workshop, presented by Toby Kurien and Dr Schalk Heunis, will introduce you to Android development. All the basic concepts pertaining to Android development are covered, such that you will be able to create your own internet-connected apps. During the workshop you will build a simple Twitter client.

Course Contents
On the completion of this workshop, the delegates will have an understanding of :
* App icon, drawables
* Android Manifest file
* Activity, UI layout vs code
* Toasts, LogCat, Exception handling
* Layouts: landscape, portrait, etc.
* UI building, LinearLayout, layout weights
* Resources: strings, arrays, colours, dimens
* ListView and Adapter
* Multi-threading, UI Thread, AsyncTask, Runnable
* HttpUrlConnection and JSON parsing
* Menu items and Intents
* Dialogs

Date / Time

The course is from 9:00 – 16:00 on 4 May 2013
Course date to be announced

Venue

House4Hack in Centurion – 4 Burger Ave, Lyttleton Manor, Centurion

Cost

R1200 (40% discount available for House4Hack members – please chat to Toby at a Tuesday meetup) – this price includes snacks during the workshop and  lunch.

Requirements

You will need to have experience with Java or a similar modern object-orientated language. Please bring a laptop with the latest Android Development Toolkit installed. For download and installation instructions visit http://developer.android.com/sdk/index.html 

Since the Lathe arrived at H4H there has been considerable activity around it:

• Kobus showed Guy and I  how to weld / grind / cut and we made a working table for the machine – the wooden top supplied by Fanie and delivered by Org
• Guy and I cleaned the machine with some paraffin and gearbox oil – basically stripping the machine and reassembling – in the process replacing some broken bits etc
• Kobus and I repaired the belt cover that was partially broken

And last night Jandré made some cutting bits for parting-off and turning – he used the grinding wheel to masterfully craft these tools from existing (broken & chipped) high speed steel bits:

Jandré really knows his stuff and under his instruction, we took turns to part-off and turn various pieces of metal:

We are planning an introductory course soon, so watch this space!

Latest instalment of Let’s Talk Hack is all about iOS Jailbreaking and James takes us on a journey behind the scenes on what happens when you jailbreak an iOS device and what the consequences are.

He analyses the envasi0n jailbreak and explains step-by-step the how, why and what – it’s a bit longer than our usual shows but definitely worth the watch:

For more information and resources, go to http://lth.letstalknetwork.tv/ios-jailbreak-watch-the-outbreak-lets-talk-hack/

Exploring the Blackberry Z10, Toby spent two days learning QML and at the same time successfully porting  SHAC (our mobile based access control system) for BlackBerry 10 users.  

QML is part of the Qt framework that Blackberry 10 uses for App development.  From Wikipedia: “QML (Qt Meta Language or Qt Modeling Language^[2]) is a JavaScript-based, declarative language for designing user interface–centric applications”.

The source code has been committed to the OpenSHAC project on Github: https://github.com/house4hack/openSHAC - look under the blackberry folder to get an idea of QML.

The app implements all the current SHAC features, including sign-in and driving directions to H4H Centurion.  Further, BB10 has something called Active Frames, which is something between a tile and a widget – when the app is “minimized” it appears on the homescreen as an Active Frame which can display custom content. At the moment the Active Frame for SHAC shows the H4H logo, but in future could show the number of people at the house or info about the next event.

Below some screenshots:

Main interface

Menu

SHAC Active Frame

Update: the app has been accepted for general consumption on the Blackberry app store: http://appworld.blackberry.com/webstore/content/26269875/?countrycode=ZA

Recently Nick had a requirement to present his Electronics Course .  He had to add MOSFETs and VMOS Trani’s to his course and  needed more power supplies for his students to do their experiments

He thought of What Peter did to make a PSU for his 3D printers using a PC Power supply.

The older power supplies have their own On/off switch.  The new ones (ATX PSU’s) need a switch between the Green Line and Ground (Black)

Drill holes on top of the case

Black Banana socket connected to Black wire = GROUND
Red Banana socket connected to the Red wire = +5Volts
Yellow Banana socket connected to the Yellow wire = +12Volts
Blue Banana socket connected to the Blue wire = -12Volts

you may want to parallel some more of these wires of the same colours for more current

Add a Red LED with a 330 or 470R series resistor connected between the Grey wire and ground (Black wire)

Don’t forget to insert chassis mounted fuse holder in series with all the above sockets

This gives you a 5V 30A and 12V 15A depending on the PSU you use.

Nick suggests that you use 3A or 5A fuses to prevent frying your circuits

After he made his poor mans bench power supply he found they are very popular on the Internet!

Here are some photos of the modification and the final product:

Philip explains how to create a mobile FM transmitter using a Raspberry PI and Arduino in the latest instalment of Let’s Talk Hack:

This webcast was recorded at House4Hack in the Let’s Talk Network studio – for more information and live shows go to ltnet.tv

Last night saw the first meetup of House4Hack KZN with 9 people turning out for first meet.

Peter says some interesting topics discussed, amongst others:
- DIY Telescopes – Ed told us how he grinds his own lenses
- Muscle Wire
- Projects we’d like to tackle
- Interhackerspace Sumo Challenge
- Possible co-workspace rental to help secure venue (several freelancers pool to rent a space we use as office by day, hack by night)
- House4HackKZN 3D Printer almost done
- CNC Project
- Home Automation
- Cold-Drip Coffee

Here is some pictures of the session in progress:

If you are in the Durban area, please join the KZNHouse4Hack mailing list and attend the next meetup.

iLifestyle is a new show that started in February 2013 on SABC1; it airs on Thursdays at 18:30

The show explores how technology affects peoples everyday lives and one of the elements of ‘iLifestyle, is the profiling of South African inventors who have developed or use technology as a way of solving an existing problem or enhancing one’s life.

The team was at House4Hack today shooting a short segment which was initially intended to cover Blumote, but after they heard and saw that we are opening the door and gate using smartphones and smartwatches, SHAC was included.

I took some photos of Thuli (presenter for iLifestyle) interviewing Toby:

It was lots of fun working with the team, who seemed genuinely interested in what House4Hack is doing and are planning a follow up show, where more of our inventions can be showcased.

Yesterday House4Hack got a new member of the family – a combination mill and lathe!

I was sitting at H4H minding my own business when first Guy, then Org, then Kobus arrived – ready for a road trip, so I could not help myself and tagged along.

Kobus found the machine advertised on Gumtree for R6500 and immediately knew this was excellent value for money, having been shopping around for the last couple of months.

The previous owner (Gideon) stays in Witpoortjie – this is a small residential area next to Krugersdorp.  And with the traffic, it took us about an hour to get there.

While I was taking photos, Guy, Org, Kobus and Gideon (yes it takes four people to carry), loaded it and tied it onto Org’s bakkie.

Forty five minutes later, we were back at H4H and unloaded the machine – this time with the help of Bernhardt.

Here are some photos of the machine and the moving process:

So what next?

1. Need a table to work on – we will be buying some steel and welding
2. Course on how to use this safely
3. [Insert you project idea here]
4. Profit!

I have been playing around with infrared remote controls as part of the upcoming Introduction to MSP430 course – Guy and I were looking for an interesting use of PWM and timers, so the suggestion was to produce an infrared signal using an IR led.

I set out to learn a bit more about IR and prototype using the Arduino. After searching online, I found Ken Shirriff’s excellent IR library for Arduino on Github: https://github.com/shirriff/Arduino-IRremote

It supports some standard TV remote controls and a “raw” mode which looked promising for controlling other things, e.g. my DSTV remote control, air conditioner etc

In this mode you can give it an array of unsigned integers. For example:

unsigned int raw[36]={250,842,242,2374,...,250,81862};

For background on how IR remote controls works check out this article on the irq5 blog.  In short the signal is encoded in bursts of “on” and “off”.  When the LED is on, it is PWM’d at a certain frequency. To use the “raw” mode, we need to know the PWM frequency (typical values between 35-40 kHz) and then the “on” and “off” durations.  The array is then made as follows:

unsigned int raw[36]={"duration on","duration off",....};

Using an IR LED, a resistor (e.g. 10K) and an oscilloscope, one can readily discover the signal sent from the remote control:

IR Led and 10k resistor

The duration of seven modulation cycle for the DSTV remote control is measure as 183uS, which corresponds to ~38kHz.

To get the on-off durations, the easiest is to use an IR receiver and the InfraredReceivers sketch found on http://playground.arduino.cc/Code/InfraredReceivers

Infrared receiver

Infrared receivers removes the 38kHz and gives a digital HIGH / LOW for the received pulses.  The Arduino Playground sketch samples the duration of these pulses at 4uS and prints to the serial console.

However, to use the output I had to subtract 10uS from each measurement – I suspectthis is an additional delay in IRremote library to switch the LED.

Muting DSTV

Connecting an IR LED to pin 3 through a 220 ohm resistor

IR LED connected to pin3 and 220 ohm resistor to ground

and running the following sketch mutes DSTV PVR:

#include <IRremote.h>
IRsend irsend;

void setup(){}

unsigned int raw[36]= {250,842,242,2374,250,834,250,2790,250,1254,
250,1258,246,1258,242,1670,250,12938,254,838,250,974,250,698,
242,838,254,694,246,2370,254,698,246,694,250,81862};

void loop() {
  irsend.sendRaw(raw,36,38);
  delay(2000);
}

Next steps is to apply this to the Airconditioner at House4Hack, to be able to control that as part of the course.