Electronics » TamsPalm - the Palm OS / web OS Blog

iButton overview

May 252006

Dallas Maxim’s iButtons are very popular. For example, they protect the door to the IT room of our school from unauthorized access. But adoption for small projects has been a little slow-and this, Dallas Maxim just released an excellent application note that explains more about what an iButton really is.

Basically, an iButton is a Dallas Maxim 1wire machine that is enclosed in a very sturdy, round metal tin. But Dallas Maxim probably can explain that much better:

What is an ibutton

The application note starts off at how an iButton is constructed, and then goers on to sturdyness ratings and also gives a short overview of what functions are available in iButton format.

Creating your own bluetooth speakers

Electronics No Responses »

May 102006

A2DP is a popular solution for wirelessly transmitting music via Bluetooth. Many headphones support A2DP by now, however, no regular speakers with A2DP interfaces have been produced so far.

However, a blogger wanted bluetooth speakers for his HTC machine-and he had a pair of broken logitech bluetooth headphones. So, he decided to wire it all up, and out came A2DB capable bluetooth speakers.

Get the full hack here:
http://gadgetfreak.typepad.com/gadget_freak_blog/2006/05/a2dp_speakers.html

List of pinouts for hardware

Electronics 4 Responses »

Apr 132006

When building hardware, you sometimes need a pinout for a device or cable. Finding it usually is incredibly difficult-unless you have pinouts.ru handy.

This site contains loads of pinouts in english language, accessible for free, no diallers, no frills! A lovely site, I can reccommend it fully!

http://pinouts.ru/

LCDs now take any shape

Electronics No Responses »

Apr 112006

ElectronicsTalk just reported that Digital Displays now takes orders for quantities of 1000+ pcs of all kinds of screen. The great thing about this bit of news is not the availability of displays; much rather, the news is that those screens can take any shape needed. They can be round, starshaped, can have a hole in the middle, could even be Tamoggemon-Logo-Shaped…

Emulating Li-Ion batteries with a NiMH cell

Electronics No Responses »

Mar 192006

LiIon batteries are rather unpopular because they are difficult to replace on your own-the readers of the WristPDA yahoo group can chant a song about this problem.

Dallas Maxim apperently predicted the chant, and recently released an application note covering a circuit that converts a single NiMH cell into a “Li-Ion battery”-at least while the discharge process is running:

http://www.maxim-ic.com/appnotes.cfm/appnote_number/3744

Replacing Motherboard chips

Electronics, Uncategorized No Responses »

Mar 052006

Hack-a-day has an interesting howto on replacing motherboard chips for notebooks and other boxen.

In the example given, they exschange the FireWire chip of a Dell notebook, but the advice can be applied to most other planars and PCB’s too.

Visit the story here:
http://www.hackaday.com/entry/1234000770073565/

LED Matrix driver, PC communication,.. done the Dallas Maxim way

Electronics No Responses »

Mar 022006

Dallas Maxim has a really cool application note online about their microcontrollers.

They present a PCB and a Windows software that autmoatically fectes stoxck exchange data off an internet source and displays it on a led bar, sort of like a ticker would. While I am not sure how many of the readers on TamsPalm are stock traders, the ideas presented can be applied to many, many different fields of business.

USB for your own hardware-with the MAX3420E

Electronics 3 Responses »

Dec 042005

From the moment USB first hit the market, many people were unhappy about it-I mean DIY electronicians who power motors,… from their PC’s. Connecting a fan motor to the COM port for cooling spaghetti(no joke, did that once) is an easy task…

Anyways, Dallas-Maxim recently released an IC called MAX3420E. This IC is said to make USB accessable from an SPI interface with no major efforts.

The following Application notes contain further information:

APPLICATION NOTE 3637-Add USB to Anything

APPLICATION NOTE 3690-USB Enumeration Code (and More) for the MAX3420E

How do you connect your circuits to USB?

The return of the DSP

Electronics, Hardware 2 Responses »

Oct 262005

Apparently, the DSP wasn’t such a stupid idea after all. Anyways, it would have been-if Palm would have been able to release the documentation for the Tungsten T series DSP. Anyways, those days are gone-but BroadCom now targets mobile phones with a new multimedia processor(that essentially is a DSP).
The BCM27xx family recently got new members that can do the following:

H.264 CIF video encoding/decoding at 30 frames per second and TV output
Support 5mpixel cameras
Do VGA MPEG4 video
All members of the family are software compatible

Do you believe that DSP’s have a future? Or do you believe that rising CPU performance and lack of SDK’s will kill those cores on the long run?

It flashes-Fixed

Electronics No Responses »

Nov 172004

The article about the Tungsten T5 hat brought me quite a few comments-including a flame in German! Thanks to everybody who commented and helped me update my understanding of Flash chip architecture.

Actually, there are two types of flash: The NOR Flash and the NAND flash.
NOR Flash is the older of the two(developed by Intel 1988), and is the one I have practically used in my projects. Lets discuss the differences here:

NOR Flash
This Flash memory type can be addressed byte for byte. It basically works like a SRAM chip that doesn’t loose data when powered off and works a bit slower. Flash’s are only sector-erasable.
Programs can be run from it because it basically is like RAM when being read-and it has been used ever since the Palm III to store the OS of the Handheld. It didn’t get lost when the Handheld was reset and out of power, but it could still be updated(I say could, because PalmOne didn’t always release Flash Upgrades recently, e.g. Tungsten T!). ROM’s couldn’t be updated….

NAND Flash
This is the new kid on the block here-and I haven’t ever ever seen such a chip in action. You feed a sector address into the chip, and out comes a serial stream of the whole sector. Writing is also accomplished in whole sectors.
Since it is very difficult to execute a serial byte stream, programs cannot be directly run from this kind of flash! However, it is way cheaper than NOR flash.

This was an interesting stroll through electronics. I maybe get my lab back working someday(damn accident), then I will give you further coverage on the topic!

Find further Information in the Wikipedia on http://en.wikipedia.org/wiki/Flash_memory