Comments for Frank's Random Wanderings

Comment on Blackfin Fast JPEG Encoding by frank

frank — Fri, 25 Jun 2010 05:09:58 +0000

First off, run the code through a profiler to see which functions are taking the most time. It might not even be your code – you might be calling some really slow libraries. Then try to optimise the code algorithmically in C as much as you can. Only when you’ve done all you can that way, do you take the painful step of writing assembler.

Comment on Blackfin Fast JPEG Encoding by Bill Strahan

Bill Strahan — Fri, 25 Jun 2010 03:23:26 +0000

What about a REALLY fast jpeg decoder? I’ve got a CE app that we distribute on an XScale based device, written in .net. I’ve put together a large C++ library to handle some image stuff (rotation, zooming, etc.) but the bottleneck is how quicky he images are being decoded by .net.

They’re just 256X256 tiles but they take more than 100ms to decode on a 624 mhz processor. I’m sure it could be MUCH faster, but dont’ know where to begin.

Bill

Comment on Atmel Xmega ADC Problems & Solutions by Rob

Rob — Wed, 05 May 2010 13:09:45 +0000

Thanks Frank.
Im using an XMegaA3 device and have changed the design to incorporate all your valuable recommendations!

Comment on Atmel Xmega ADC Problems & Solutions by frank

frank — Fri, 30 Apr 2010 14:53:41 +0000

There are lots of MP3 player projects over at www.avrfreaks.net

Comment on Atmel Xmega ADC Problems & Solutions by abey

abey — Fri, 30 Apr 2010 13:53:42 +0000

is there any circuit for usb flash drive mp3 player,please tell the simple concept about reading mp3 from usb flash drive and how it convert it to sound,

Comment on Atmel Xmega ADC Problems & Solutions by frank

frank — Thu, 22 Apr 2010 00:04:18 +0000

Hi Martin,

I don’t know the mask revision, and with the boards now out of my hands I’m unable to hook one up to a programmer to read out any registers. However this is what can be read off the top of the chips:
ATXMEGA16A4
AU 0921

Comment on Atmel Xmega ADC Problems & Solutions by martin

martin — Wed, 21 Apr 2010 21:22:11 +0000

Hi Frank,

Wow, thanks for all the info. Can you tell me which Xmega and mask revision you did your tests on.
I’m working with 128A1 and Rev H (I have some Rev G as well). I thought that single ended, unsigned with the internal 1V reference would be OK for what I need to do but I’m having to reconsider that.

Comment on GoDaddy sucks, and a new web host by Kirk

Kirk — Thu, 15 Apr 2010 23:50:44 +0000

that was suppose to say GoDaddy rather just so we are clear on who I am ranting about.

Comment on GoDaddy sucks, and a new web host by Kirk

Kirk — Thu, 15 Apr 2010 23:44:43 +0000

Seriously advice against anyone signing up for a godday account!!!!!!! Hard to imagine that any web hosting service could be worse. Poor, slow and confusing admin interface! Absolutely useless customer support! Problematic emails! These are just a few of problems I have encountered in my relatively short time using this service. Luckily for me my site is still in the setup and testing phase so changing to a different provider will not cause too much of a problem.

Comment on Atmel Xmega printf HowTo by Jörg

Jörg — Fri, 09 Apr 2010 20:36:36 +0000

ups second dosen´t works