Category: hardware

Tommy gave me a parallel character LCD that he's had stashed away for a long time. He was on the right track, just never finished it. I looked at what he'd made, based on the original schematic. I hooked the LCD to a DB25 connector that was already soldered to a ribbon cable, hooked it up and it worked.

I noticed that the brightness and contrast knobs were set and didn't need to be adjusted. One pot was even set to 0! After a few minutes I was able to boil down the circuit to just use one 50-ohm resistor.
Here is the final "simple" schematic:


This schematic should work on any Hiatchi HD44780-based character LCD, so long as it only has a single 8-bit connection, like the Seiko L2014.

update: You may also use this LCD screen test app to check your LCD: http://www.neodux.com/projects/lcd/LCDsetup.zip

Grendel sez: You da man, sir. Thanks. Here is a picture of the LCD in action. Videos are here (2.5Mb, avi) and here (6.9,avi).

update: I (grendel) just got the LCD working under linux using lcdproc/LCDd. Now, if only I could figure out how to get lcdvc to work with it, I'll be even more pleased.

This afternoon I updated the version of Xbox Media Center that was installed on my hacked Xbox. If you recall, I installed most everything using Slayer's AutoInstaller, which works great for getting you up and going quickly.
Xbox Media Center allows you to access all of your MP3 and WMA files on your Xbox HD as well as your Windows Network. You can also play music from iTunes and Shoutcast servers. Not only music is available on XBMC, you can also use it for slideshows (which I've done with our honeymoon pics) and for playing movies (DVDs and video files like .mpg, .avi and .wmv). The older version had all of these features, but one of the new features is the ability to change RSS feeds to receive the latest news headlines. Slashdot and Yahoo news headlines can be accessed like this.

The kicker for me was the ability to have Milkdrop for visualizations for the music. The default visualizations for MP3s and the like was your average run-of-the-mill blurred oscilliscopes and spectrum analyzers. Milkdrop adds a virtually limitless array of plugins to allow for any mix of visualization plugins. The new version also features an improved web-interface to control music/video playback on the Xbox. Couple all these new features with the Xbox remote control and the enhanced audio adapter to allow for Dolby/DTS output and you've got a setup that rivals most any homebrew home theater PC setup.

update: After installing XBMC I found a few additional scripts that are very handy. My favorites that I have installed are XMovieGuide, which shows movie times at area theaters; XRadar, shows local area weather radar; and the 'PBS Frontline script', to view the streaming video archives of the television show "Frontline" on the Xbox.

I just got back from the local Target where I picked up a JuiceBox. (warning: annoying Flash on that site!)
What the crap is a JuiceBox? It's a kid's portable media player that Mattel released for Christmas '04. They didn't sell very well at their retail price of $50, so stores like Target and Walmart cleared them out at huge discounts. Walmart cleared them out months ago, and according to one source, was selling them for as cheap as $6!
Target, just this week, dropped their in store prices from the already discounted $24 to $12.

"Okay, so why did you buy an unwanted toy?"
Recently, Slashdot ran an article about hacking your JuiceBox into a picture frame. This is my current goal, as it is for several others. The key to the mods surrounding this little gadget is that it runs a version of uclinux. We'll see how this goes.

update: Pfft, well that was cake - no real "mod" involved. The "MP3 Starter Kit" that I bought for $11 at Target includes a CD that converts pictures to a proprietary format (.jbp), compressing each image down to 57k. You can tell the image quality has been lost, but on a screen this small, you don't really care that much. I'm sure as the hacking community grows, there will be more options available. For those interested, if you have an SD card and USB adapter for your computer, you can play MP3s right out of the box. The software kit gives you the image conversion software, as well as an adapter to allow the SD card to be plugged into the media card slot on the JuiceBox unit. (I believe a few people have tried to make their own adapters.) Aside from the JuiceBox card adapter, the kit doesn't actually do anything to the Juicebox.

Due to the extended conversation in the shoutbox, I though I'd give you guys some basic info on wireless phones and the technology they use. For the purposes of this discussion, I will cover national carriers only. If someone wants information on a regional or international carrier, I'll provide you with whatever I have.

We'll start with a technology near and dear to my heart. It's called CDMA which is an acronym for Code Division Multiple Access. It is a method of stacking calls on a cell tower wherein each call is assigned a specific and unique code. In so doing, the tower can handle somewhere in the neighborhood of 30 calls per megahertz. It was developed exclusively by Qualcomm in a lovely building that is next door to my office.

Verizon Wireless and Sprint PCS, ranked second and third respectively in terms of market share, are the two national carriers that employ CDMA currently. Most of their networks are CDMAOne, or 2G services with slower QNC data speeds. Verizon has rolled out a 2.5G network with EV-DO (Evolution, Data Only), sometimes referred to as 1X, that boasts theoretical data speeds of 300 to 500kbps.

In terms of coverage, Verizon's network is currently the largest in the United States. Their plans, however, are somewhat more expensive than other carriers. This is due to the money they spend on their network making it one of the best in the nation. Sprint, on the other hand, ain't too shabby either. Their network is good, but not as good as Verizon. In many areas where Verizon has a strong foothold, such as the northeast and here in Southern California, Sprint's network is a tad shoddy because they have no incentive to upgrade.

And now, we move to a second post for GSM.

GSM, you ignorant slut. Not really, but I don't care for it much. GSM is an acronym for Global System for Mobile Communication. GSM works off of the older TDMA systems in using timestamps to stack calls on the tower. GSM can stack seven to ten calls per megahertz versus upwards of 30 for CDMA.

GSM is used almost exclusively in Europe making it more of the, "world standard" than CDMA. Many carriers sell, "World Phones" that are tri-band and capable of using the networks here in the States and in Europe. Data speeds on GSM are significantly slower than CDMA, and while new technologies are being developed to bring up the transfer rates, it will never really catch up with CDMA, much less overtake it.

For coverage we look to the number one wireless phone carrier in the United States, Cingular. Cingular recently acquired AT&T, and as their new marketing campaign is screaming, they now have the largest network. What they aren't telling you is that most of AT&T's network is TDMA and does not support GSM. AT&T was starting upgrades but never finished. Their coverage is very, very good. For coverage, their only competition is Verizon. However, CDMA penetrates (lol) buildings much better than GSM.

T-mobile is also a player. Instead of having a zomg huge network, they offer fantastic values in phones and service plans. T-mobile is great if you're in a metropolitan area and never leave.

Just incase anyone is wondering, all of the carriers have coverage maps on their respective websites. Additionally, tons more information about both CDMA and GSM are available from our friends and Google. Feel free to post questions in the shoutbox or in comments and I'll do what I can to answer them. And now I'm going to bed. Mmm. Bed.