YourITronics

June 19th marked the launch of Apple’s “fastest, most powerful iPhone yet”, the iPhone 3G S. Not sure what the S stands for (I’ve came across some guesses while surfing the web, speed, sex, sucks just to name a few), but according to Apple’s official website it should be “up to 2x faster” than the old iPhone 3G and should have a digital compass that reorients the map as you change the direction you’re facing, a 3.0 megapixel camera that can also record VGA video in 30 frames per second and voice control for calling and playing music.

On the outside, the new iPhone remains true to the traditional design of Apple – minimalistic, elegant and slim. As we unfold its shell, the new smartphone from Apple reveals a few interesting improvements. First, the PCB is more compact than before, with nearly every component on the top side of the board. Second, the CPU has changed – iPhone 3G S features the ARM A8 Samsung S5PC100 processor, which runs at 600Mhz with 32KB L1 cache memory instead of 412Mhz with 16KB cache like the ARM 11 Samsung S3C6400 used in the previous model. The new iPhone 3G S also features the PowerVR SGX graphics accelerator that runs at 200Mhz.

The smartphone has a Toshiba NAND flash memory and a new combo in the wireless department: the BCM4325 from Broadcom. It also received an important upgrade to the battery, from 1150mAH to 1219mAH, and it is rumored that the iPhone 3GS’ battery life will be 15-20 percent longer than the iPhone 3G’s. A great and necessary improvement for all iPhone 3G S users.

The most important upgrade of the new Apple device is clearly its Applications Processor Core. With a clock speed of 600Mhz, 256MB DDR SDRAM and the PowerVR SGX graphics processor, the new smartphone has the muscle to manage all kinds of demanding applications and, with the help of the SGX, that includes some serious gaming. The longer battery life also supports this idea and the iPhone 3G S might turn out to be quite a powerful mobile device.

Inside the iPhone 3G S: [Link]

The idea behind this project was born when a friend asked me too take a look at he’s broken GPS unit (MyGuide 3000) to see if I can fix anything. I started checking various parts like voltage regulators, but found nothing wrong. The gps unit was still not powering up so I checked the cpu, an ARM9 from Samsung and found it broken. Of course I couldn’t do anything about that, because of the BGA package and the bootloader needed after replacing it so the gps unit became a source for parts. The most useful and interesting parts from the GPS were the LCD display and the GPS module.

The GPS module is a RoyalTek RGM-3550LP which has an integrated antenna and is powered by SiRF Star III technology. I immediately connected the gps module to my computer’s serial port(using a max232) to test if it was still working. To my surprise the gps module was working and sending NMEA compliant sentences. Then I had this idea of using the gps module as a navigation system together with a notebook computer, but notebooks don’t have a serial port so I had to use a UART to USB bridge.

The most common used UART-USB bridge is the FT232 manufactured by FTDI which is about $4 which is a fair price because you don’t need any external parts for this chip except some bypass capacitors and that saves you time and money. I never used the chip before but it was really easy to get it working. It even has this custom utility that let’s you program some features saved in the internal EEPROM like the maximum bus power and the product and manufacturer descriptor strings. Anyway these are the only two settings that I tinkered with, but the utility let’s you change some more stuff.

The next thing I had to worry was where to get the power for the GPS unit, because it needs 3.3V and the acquisition current is 50 mA. The FT232 has an internal voltage regulator which provides 3.3 V and 50 mA but I decided not to use that in order to extend it’s life so I ended up using the TPS2148 which is a 3.3V LDO from Texas Instruments. It’s specifically designed for USB peripheral power management, and it’s tiny package(MSOP-8) made it ideally for my application. The TPS2148 handles the current limitation so I didn’t had to worry about that either.

After figuring out the parts I was going to use and the schematic, I had to chose an enclosure for this project. The main target was to get it as small as possible but the limit was the gps module size, I couldn’t of got it smaller then the module . So I went and searched for a plastic enclosure, and I found one just perfect for what I needed, the PP85D from Supertronic. The gps module fits just nicely between the screw channels.

Then after I got the enclosure, I made the pcb using the photo etching technique.. I assembled and tested it, and to my surprise everything worked just fine from the first try. I’m usually not that lucky when I make stuff using new IC’s that I haven’t used before. Sometimes I don’t pay enough attention to the datasheet and I get some small stuff left behind and that messes my entire circuit. Anyway, happy as I was that everything worked from the first try, I put everything inside the enclosure and snapped some pictures of it. As a final note, this was a great project which I enjoyed making, and I really recommend you do something like this if you have a gps unit laying around.

more pictures:

parts list:

• RGM-3550LP gps module x1
• FT232RL x1
• TPS2148 x1
• capacitor 10uF x3
• capacitor 100nF x3
• led x1

schematics and board files were designed in Eagle and can be downloaded here.

This article has been supported by Wireless Matrix, which is a leading provider of Fleet GPS systems and wireless data communications services.

Nowadays the LCD and plasma technologies have become pretty cheap and big screen TV’s are more affordable. But your movie experience isn’t complete without good sound. DIY is a very good solution for a home theater speaker setup and subwoofers are the easiest component to build. Once you found a good speaker driver and made a cabinet according to it’s parameters all you need to do is give it a place in the whole system.

Active filters are the best solution to integrate the subwoofer in the HT. This way you add more control, flexibility and you eliminate negative influences of passive filters. The above circuit offers a very simple but effective solution. Using only a handful of electronic components cost is very low. The filter, as it is presented, has two main stages. The first stage, using half of the TL072 IC, sums the “left” and “right” channel into a single channel. By varying R3 you can adjust the gain.

The next stage forms the filter itself. It is a second order filter with 12db/octave slope. The corner frequency is set by the values of R5&7 between approximately 20Hz and 100Hz. You will need to set this frequency to match the other speakers, room and placement. If you don’t have any measuring equipment than trial and error is the way to go. Now there is one more thing you can do to make it really good. If you look at the first stage you will see that the signal will be 180 degrees shifted in phase. This may or may not affect your sound, it really depends on your room and speaker placement. However it would be good to add one simple inverter stage before the filter with gain set to 1 and with a bypass switch. This way you can select 0 or 180 degrees phase shift.

Subwoofer Active Filter: [Link]

This project was probably inspired from the commercially available gadgets, I think there are great but don’t think they worth 100-200$. Now their are many alternatives, from old laptop displays to OLED screens, the presented project uses a small display similar to the Nokia display and a PIC micro controller, the authors made the entire project public including the schematic and pcb files in Eagle format.

The screen used is cheap since it is a copy of the Nokia display, they aquired it from Sparkfun, where you can find source code for different types of micro controllers, the pictures are stored in a microSD card, in the current firmware version are some limitations to the bitmap format and no subfolders are supported. The PIC device used has free C compiler support from Microchip, which is also a great thing if you want to improve the firmware.

The pcb is really compact but not overcrowded, it is possible to replicate with hobbyst equipment, it is a great middle-level project for you to thinker.

Digital picture frame: [Link]

You’ve probably noticed the pictures from my last projects… they look pretty cool. That’s because i got a new camera, a Sony DSC H9. The macros are great, i can see the particles of dust on my circuit boards, the landscapes are great, i took some stuning pictures in my vacation in the mountains.

I’m not gonna go trough all of the aspects in this review, I’m just gonna tell you what impresses me about this camera. I payed for it at a local retail store about $520 complete with a 2 GB memory stick pro duo. The camera was nicely packed and accesorized. For example i got a cool remote control, that i can use to take pictures remotely. I also got a shoulder strap which you don’t get on most cameras.

The battery, is sony, as expected and it last actually more than they say it will. They guarantee that it will last you 300 photos, but i take aprox 600 photos with one charge.

If you plan on getting one, i suggest you take no less than 2 GB memory card. Because on 2 Gb it rarely gets full, and you’ll alaways have room for more pictures when you’re away from your computer and you can’t download them.

Another good thing about the camera, it’s the 15x zoom complete with image stabilization, which helps you get more acurrate details into your pictures when shooting at a distance.

The camera also has other nice functions like many shooting resolutions, the i prefere beeing the widescreen mode. In my opinion this is the best choice in digital camera before moving into the SLR category.

I hear that digital photo frames are they way to show your pictures arround the house these days, maybe one from Sony will work ok together with my H9.