Archive for June, 2010

Touch me touch me

Wednesday, June 30th, 2010

On a more positive note; a package out of Thailand has arrived. Inside was a 2.8″ TFT display with touchscreen. I’m quite happy with this because it was a bit of a gamble. It comes from rftechworld and was the cheapest I could find (ignoring the fact that I love ordering stuff from unknown places all over the world ;)). Something I could not find was any information regarding them, it could have turned out to be a scam. But to my delight it all worked out fine and I will certainly place another order with them when needed.

The display was shipped in a very joyful padded envelope (take a look at the Thailand Post website and you know what I mean). This may sound scary, but the display itself was packed in a sturdy clear plastic case. Totally unexpected, but very welcome protection.

Another surprise comes in the form of pinout. According the website and provided documents you get either a hardwired 8-bit interface of 16-bit interface. But this is not what arrived. Instead all needed pins are made available and you can select how many bits you need by connecting mode pins to GND or Vdd.

This component goes into the remote control unit. For now it’s screen + breakout board for easier development, but the screen can also be gotten without the PCB attached to it. Resolution is 240×320 which should be more than enough for this project whilst being small enough to fit in the palm of your hand. Required power is 2.8V typical, but 3.3V is within spec. The display has a Sitronix ST7781 controller (262K colours) and the breakout board comes with AD7873 touchscreen digitizer assembled.

And spammers ruin the party once again…

Wednesday, June 30th, 2010

Comments are disabled. Be sure to thank your local fuckhead spammer for that. Did I already mention I hope these retards burn in hell? If not, I hope these retards burn in hell! *sigh* that didn’t take them long…. so far they have a 100% trackrecord of messing things up. After having run various websites on this domain for the past 10 years I can honestly say I’m done with removing spam. There’s no doubt in my mind anymore that truly open website where everyone can contribute belong to the previous century. It’s a real shame.

@spammer

From the bottom of my heart I’d like to say thank you and wish you get the worst disease out there. Hope you die soon and give my regards to the insects eating your rotting corpse!

Fake Atmel chips revealed

Monday, June 28th, 2010

A while ago Sparkfun had a story about a batch of non working Atmel chips. The guys at Sparkfun had some help from Atmel’s Failure Analysis labs and as it turns out these fakes actually have an ON Semiconductor die inside. Read the latest chapter of this unfolding story here.

Vuvuzela blowers should be shot on sight

Saturday, June 26th, 2010

Anyone else getting totally fed up with those Vuvuzela blowers? I’m not talking about the bees you hear in the background during a match. I’m talking about those kids that walk through the streets in the morning, the afternoon and evening blowing their lungs out. Latest example; lying in bed barely awake this morning and what do I hear through the open windows… Ffs, it was sweet in the beginning, but by now this pretty much sums it up:

Blow that vuvuzela on more time and I’ll shove it down your throat and make you suffer a slow and painful dead..

Aaah, I feel so much better now.

Useful things come in small packages

Friday, June 25th, 2010

Just love these small dev boards. Makes live so much easier!

However I am curious how long it will keep working. The PCB is pretty flimsy and sticking it into a breadboard over and over again is most likely not going to make it last for years. Time will tell.

Dead nub club

Thursday, June 24th, 2010

By sheer luck of being in the right place at the right time yours truly just became a member of Pandora’s tiny 7-people ‘dead nub club’. ┬áDead nub units are part of the first mass produced units build, but with both nubs not working. Working nubs would be nice, but a large discount makes you very creative at finding other uses that don’t require nubs :)

New to the Pandora? Check it out here

What the FLAC?!

Wednesday, June 23rd, 2010

It seems wanting to play FLAC files has some consequences. Because FLAC is lossless there’s a limit to how small the files get. Now that in itself is not a big problem, there’s enough space on SD cards these days. But the bigger the file, the higher the bitrate the controller has to pass on to the decoder. At the moment the ATmega328P is my controller of choice (why? because I’ve got a couple lying around) , but I’m not sure if it’s capable of processing high bitrates. Playing a random FLAC file on my laptop reveals an average(!) bitrate of 886 kbps. Playback was done from a 8GB class 4 SD card without problems, so if there’s a bottleneck, it’s the AVR.

Another FLAC issue is that the decoder isn’t in the VS1053′s firmware, one has to upload a patch first. It’s a 60KB patch. Of course the 328 doesn’t come with that much space, so it’ll probably end up on SD card as well. It would mean some extra firmware code to read it from the card and upload it to the decoder after power-up, but that shouldn’t be that difficult. The (compressed) FLAC patch is 60KB…. as C code. Actual binary size is only 6226 bytes. And guess what, that would probably fit very comfy in the 32K flash of the AVR. Cheers!

So true :)

Monday, June 21st, 2010

“Only one thing more dangerous than a hardware engineer with a compiler — a software engineer with a soldering iron”

Sine test

Sunday, June 20th, 2010

More good news! Hooked up the VS1053 to a buspirate and digiscope to see if I could send commands via SPI. It took a little fiddling getting the clock/data signals right, but the result is looking good.

This is just a small test using the VS1053′s build-in sine test, but it means communicating via SPI is understood and output works. Something I’m not happy with yet is the minor distortion in the signal. I have no idea if this is in the decoder, the scope, or just random noise due to the shaky breadboard setup.

Status updates

Sunday, June 20th, 2010

To keep track of the status of various projects I’ve added a status page (see “Pages” on the right). Right now it only contains the status of the music player, but it’s likely more projects will be added as time passes.