Saturday, 28 June 2014

Building a Wooden Ghettoblaster: Painting faux rust on the speakers (part 4)

This is the final post on how I built my wooden ghettoblaster.

While my previous my three previous building the front face, the enclosure and wiring it all), this post will describe the final touches I brought to this project: painting faux rust and quieting the fan of the cheap Chinese power supply.

Tuesday, 29 April 2014

DUMMYRESEND scam on eBay: You will never receive a replacement for the item that arrived broken

Ten to fifteen years ago people were scared to buy on-line and on on-line auction websites such as eBay, thinking chances of never receiving the ordered items was high without any way to ever see the item or money back.

The web has now evolved and thanks to on-line communities any rip-off is now immediately documented (through direct feedback, blogs and forums). This means that and you usually get something for what you paid for. This does not mean that there are any loopholes and weaknesses in processes that unscrupulous sellers exploit. This article will go through what I call the 'DUMMYRESEND' scam which usually happens when you get a broken item eBay.

Friday, 18 April 2014

Building a Wooden Ghettoblaster: preparing the audio and electrical hardware (part 3)

Almost finished, the speakers still
need painting
This post is the continuation of my two previous posts (building the front face and the enclosure) and I will go through the preparation and wiring of all the electrical and audio equipment in this project. 

Note: there will be another post in the near future about finishing a couple of details (like painting the speakers in faux-rust).

Sunday, 6 April 2014

Set a 'secret' VPN with your second residence using OpenVPN and a cheap TPlink TL-WR703N

This hood is also a wifi
OpenVPN server !
Sometimes you want to connect with a remote NAS or backup service or simply want all your Internet trafic to come from another location.

If you have a second residence with a broadband Internet access, chances are that your Internet provider will supply a preconfigured (and basic) router that fits most people's needs. This router will unfortunately not let you add a VPN server on it ... (even if it were allowed by the ISP terms and conditions) because they are not going to pay for functionalities 99.9% of the population doesn't know and care about.

This post will summarise what you need to have and configure to get you on your way. As well as the best place I found to hide it (tip: it's in the kitchen... ;-):

Tuesday, 25 March 2014

Hacking the Link Bluetooth receiver for auto-on and off (with power supply)

The Link Bluetooth APTX audio
receiver (BT V4.0 with AD2P)
The Link Bluetooth is a cheap Chinese Bluetooth audio adapter providing a very decent audio quality. With this adapter you will be able to transform most stereos (or in my case the Wooden Getthoblaster I'm building) to receive Bluetooth audio.

The Internet is full of cheaper (about 5€) Bluetooth receivers but these usually come with a bad sound quality and for this reason I decided to buy the cheapest APTX Bluetooth 4.0+EDR, AD2P adapter I could find (22.99 USD):

The problem is that the engineers who designed this adapter obviously did not think about the use I was going to make of it (shame on them ;-):

The device does not turn on automatically when plugged in

I want my Bluetooth receiver to automatically turn on when powered so I can hard wire it inside my stereo and not have to press any button to make it work. I was really disappointed it wasn't the case and decided to open the 'Link' to see what I could do.

Sunday, 23 March 2014

Building a Wooden Ghettoblaster: the enclosure (part 2)

The wooden ghettoblaster case ready to
receive its audio equipment
Here are some news of my wooden Ghettoblaster project...
In case you missed it, you can find here the first steps. I used marquetry techniques to give this ghettoblaster a retro look. I did not want to build yet another box with an amp and speakers (where would be the fun in that?).

I had old 3 way car speakers lying around. These are meant to be flush mounted. If you're familiar with building speakers, reading on might make you scream (you've been warned).

Googling around, I discovered a little of the science behind building speakers and lots of people arguing about technicalities (as always). I'm therefore not going to start a debate here...

Thursday, 20 March 2014

Empirically computing the battery use of electronics

Measuring the voltage while discharging the battery
My father uses a small electronic device to measure the heartbeat of his patients during a couple of days. After playing around with alkaline and Ni-Mh batteries he realised that Ni-Mh batteries would sometimes die before the end of the recording and that any brand of fresh alkalines would work:

He came to the same conclusions most people usually come to (but failed to realise a couple of things):
  • Any alkaline he ever purchased were doing the job fine... and could therefore buy the cheapest
  • NiMh rechargeable batteries should not be trusted (note: that is if you use them like anyone else).
This article will investigate how one can estimate the battery capacity and device power consumption.