Glass Jar Speaker

Hi again,

Been busy at work and at home lately (no Phil. housemate any more and I have to do the washing up, take the trash out etc. ;-( ), so a small project, which in theory should not take long might just be the right.

I brought two 8ohm, 3W speakers a while ago. Looks a bit like tweeter to me, but for speech and light music, they should be ok. I am was looking for something to house them. 

The original idea was to use them as the speaker for the FM radio I was building, but thats' taken me longer to get the software right (just can't get it to auto scan, manual tuning is ok). Anyway, I have also order a small 3W Class-D amp. like this one:

http://www.ebay.com/itm/2-Channels-3W-PAM8403-Class-D-Audio-Amplifier-Board-5V-USB-Power-/190723806259?pt=US_Home_Audio_Amplifiers_Preamps&hash=item2c68065433

Could be power by an USB port. You will be surprise how small it is, well I am anyway. So may be I will put them together and make a pair of small powered speaker. I know you buy them dirt cheap, but whats' the fun in that?

Anyway on with the search for an enclosure. I saw this a while ago on the net:

http://sarahpease.com/audioJar

and thought I might do something similar. So on to the HK$12 shop and I found these candy jar, just right for the job! I one each with different colour cap, so I can identify which is left and which is right channel.  So on with the job. Now I already anticipated that most mechanical task will be cutting holes (thats' why I thought it will be a short project). Now cutting holes on the cap for the speaker is easy, just happen to have the right size hole cutting and there you go:

a bit of hot glue and it is looking nice!

But cutting hole in glass is another matter. I know you can do it, from the above website and there are special bit to do this, but I just never done it before. I started using very small engraving bit from my Dremal tool. Now, my advice is, if I was to do this again, is not to use a Dremal tool. They are far too fast! A normal drill with variable speed is a much better choose and you want to go real slow. Second, wet the place you going to drill before. This  serve two purposes; one it keep the drill/glass cool, so less chance of  it cracking, second, it remove the dust when you drill, glass dust in lung is not good! And the result:

Just one more thing, for those of us who is blessed with the marital blaze, do the drilling when the wife is not around. Glass drilling noise make wife nuts!

Here the finished product, the speaker side anyway.

Ben

Alternative Android Devices and ARM embedded device etc........

 Hi all,

On the thought of how Linux will conquer the world, I ran into these ARM based devices of which I could see unlimited hackabilities:

Allwinner based devices and board:
http://wiki.xbmc.org/index.php?title=Allwinner_A10_devices

and here another one just came out:
http://cubieboard.org/

Not much info on the cubie board, but the price is right and if people can latch on as much as the MK802, than it would be very interesting. It have similar spec. as the Mala A100 devices, maybe they just strip the case and sale the bare board instead, who know. Just quick search, you can now buy it on aliexpress (in limited quantity, 512MB as well as 1GB model):

http://www.aliexpress.com/item/cubieboard-prototype-512M-2012-8-8-revision/633682724.html

But as it said, it is prototype board, so you take your chances. 

Look at the embedded devices market, it is fair to say ARM based devices is taken a fair chunk of it and one reason is the adoption of  Linux on it. The tool chain seems to be quite well develop and it is quite easy to port from one model to another. All this is fine when you have 512MB or even 1GB to play around, but what happen if you just want it for a quick embedded application? An interest and very useful article from Jeelabs on the Ecosystem of development/enbedded ARMs:

http://jeelabs.org/2012/09/13/the-arm-ecosystem/

I think the main thing that will make or break the ARMs into the hobbist/maker market is an Open IDE, that is flexible enough to support different varies of the make/model/implementation of the chip. There currently so many different way to develop and upload application to an ARM board, and almost all of them are proprietary. This does not help with the adoption of ARMs; too many chooses is no chooses and a close system is no good to anyone. I think one of the reason why the Arduino platform is successfully, which in turns leads to the large adoption of AVR among the hobbist, is that it offer a open "standard", which everyone can follow. Now this "standard" might not be the best in the world, but it offer an entry point where people can enter. Once people start adopting this standard, they can stay with it, as it offer compatibility with other devices in the family or they can move on with the same standard, but with better or more advance coding, like C etc.   Now whether this will ever happens, we remain to see and I certainly will be watching, specially TI is selling this:

http://www.ti.com/ww/en/launchpad/stellaris_head.html?DCMP=stellaris-launchpad&HQS=stellaris-launchpad

TI is selling them for USD12.99 (was USD9.99 when I got mine). For that you get a ARM® Cortex™-M4F (2 in fact if you count the one which provide the USB host). Quite a powerful processor.

Ben

Update, 4/10/2012:

One step closest, but not sure about the direction. Anyway Arduino have the same idea of putting ARMs on Arduino format and hopefully an IDE to follow:

http://hackaday.com/2012/10/03/finally-an-arm-powered-arduino/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+hackaday%2FLgoM+%28Hack+a+Day%29 

Update, 5/10/2012:

Check this out for an IDE:

http://www.coocox.org/index.html 

Update, 14/1/2013:

Looks like apart from the cheap MK802 from China, the Korean are at it too. Take a look at this:

http://www.hardkernel.com/renewal_2011/products/prdt_info.php?g_code=G135341370451&tab_idx=1  

Yes, it is a Quad core Android/Ubuntu development board. It uses the same cpu as in the Samsung Android phone eg. Note II etc. 1G RAM and just about everything you need for a standalone server and at USD89! Quad core development board, now what will they think of next! It looks like better supported then the china one too. 

Raspberry Pi: The Adventure goes on.......

Hi,

Here again, just updating what I have been doing. From the blog before, I have so far:

1) Load Raspbian onto it.

Ran transmission, samba and mediatomb off it. Find the USB harddisk access will crash with cache write error, after a period of time (usually days) and will keep doing this is shorter and shorter period. Check the disk (ext4) and it say it is clean. Use the same disk on my Zotac under Linux and it is fine. I think this is a Raspberry Pi issue, may be usb related (may be firmware, as Raspbmc has the same issue). So far I have updated to the latest firmware and bleeding edge kernel, but makes no different.

2) Load up Raspbmc.

First impression was really good, well done Sam! Although it suffer the same usb harddisk issue, as I turn on upnp server. Just updated it to RC4, so far looks really cool. The only real quibble I have is during installation, DO NOT plug a keyboard in! It seem that it has a hard time resetting the keyboard and will not finish the installation. After it has completed the installation, then it will detect the keyboard  properly. I don't know if anybody else have the same experience, but here's my two cent on installation. So the next thing is to get a remote working. The Android remote works real good, but it would be nicer if I can get my aftermarkert PS3 remote working.

On the thoughts on what I really want to use the Raspi for, I beginning to have some reservation on it. I do understand it is a WIP and there are certain design feature/bugs that may have to live with (1.8v reg. making the Ethernet chip hot). So if I am looking for something that can be use for production, I might have to look else where.

Now something I really like to have is Android/Linux on the our main TV, in fact I would like Linux on just about everything and everywhere! Today your TV, tomorrow the world! So may be something like this will fit:

http://wiki.xbmc.org/index.php?title=Allwinner_A10_devices

But this is for another bolg.