When Gabriel Anzziani from gabotronics.com asked me if I would like to do a review of the XMEGA Xprotolab I said yes because although these small devices cannot replace a real tool in an electronics lab, they often serve as development boards for the devices used on them. The Xprotolab is a miniature mixed signal oscilloscope and waveform generator packed in a DIP module which makes it great for breadboards. It has a nice set of features for such a small device:

for oscilloscope mode:

• 2 Analog Channels, 8 Digital Channels
• Maximum Sampling rate: 2MSPS
• Analog Bandwidth: 320kHz
• Resolution: 8bits
• Input Impedance: 1MΩ
• Buffer size per channel: 256
• Max. Input Voltage: +/- 10V

for arbitrary waveform generator:

• 1 Analog Channel
• Maximum conversion rate: 1MSPS
• Analog Bandwidth: 44.1kHz
• Resolution: 8bits
• Low output impedance
• Buffer size: 256
• Max. Output Voltage: +/- 2V

The hardware is based on a ATXMEGA32A4 coupled with a Graphic OLED display 128×64 pixels and a TL064 quad op-amp for the analog side. What is not mentioned on the product page is that it also has FFT, Meter mode with voltage and frequency, X-Y mode and a logic analyzer. Sound nice but lets put it to the test and see how it performs.

First thing I wanted to test on the xprotolab is the meter mode; I think for beginners who build breadboard circuits it will be a very useful feature because you could use your multimeter to check some voltage or current while you use the xprotolab to check another voltage or frequency. Every electronics lab should have at least 2 meters to serve this purpose but if you’re a beginner its most likely you only have one. I must tell you that Gabriel was very helpful when I discovered some bugs in the firmware and he corrected them within hours. Unfortunately it is a work in progress and I could find other bugs even after upgrading. The firmware version used during tests is 0.95.

So to start testing I placed the xprotolab on a mini breadboard and supplied power at 5V. First thing to notice is the OLED display which is a very good choice for this application and provides nice & crisp display with good contras. The menu is not difficult, it takes about 10 mins to get used to it and learn what each menu/key press does. After switching to meter mode (VDC) I applied a 3.3V voltage through a 10k series resistor to CH1 and CH2. With both channels connected to the same signal at the same time CH1 was reporting 3.22V and CH2 3.28V while my multimeter was reporting 3.24V so CH1 was off by -0.02 compared to the multimeter while CH2 was off by +0.04. A slight offset between channels can be noticed ~0.06V. The firmware has an offset compensation feature which can be accessed by holding key 4 during power on.

After entering the offset menu it will ask you to ground all inputs and press start. I did that.. it acquired the new offset values and I continued using into meter mode to see how it affected the results. Connected to the same signal as earlier CH1 was now showing 3.19 V which is off with -0.03 compared to the multimeter but the surprise is that CH2 is not taking any measurements, its just stuck after the offset compensation. As you can see the values are pretty close to what the multimeter was reporting and really a 0.02 offset is not a big deal in most applications, but the software has a bug that’s preventing CH2 from taking measurements after the offset compensation. To fix this I just re-flashed the EEPROM and CH2 started working on meter mode again.

Next I tried the frequency measurement. I used a signal generator with a sine wave and the xprotolab was able to detect frequency down to 10Hz and up to 500KHz which is pretty good for a device so small and inexpensive. Next I tried the VPP meter mode which was able to detect values on a sine wave up to 100KHz, any frequency higher and the measurement got all weird.

Next test was on scope mode, and I was able to get a clean and accurate reading on CH1, up to 100KHz sine wave. Anything higher than 100KHz caused false readings and I could notice the amplitude going down.
I also did tests with square and triangle wave shapes and the results were the same. I did not have enough time to review the other features like the arbitrary waveform generator or the logic analyzer but I’m sure I’ll use it somewhere in a future project cause if you remember I wrote a post about how nice is to have a logic analyzer when debugging. There is one feature I felt it was missing from it though , the value of the frequency printed on the screen while taking scope measurements.(later edit: Gabriel pointed out that this feature exists and he was right, I somehow missed it. You have the option of activating and locking the cursors and this will show the frequency on the screen as 1/deltaT but I feel the position its not the best as it overlaps with the represented signal).  This is a feature commonly found on all modern scopes, and although you have the options of controlling two cursors from the menu its easier to just have the value on the screen without having to use the cursors.

To conclude the Xprotolab is a small and cheap device which besides the features enumerated above doubles as a development board with schematics and source code offered on the product page. To me its clearly visible that someone has put allot of work into this project and is using every bit of processing power from the ATXMEGA32A4 to crunch the numbers.

I was really interested about it when Seeed Studio first announced the DSO nano on their blog, unfortunately I was not able to get one of the beta’s which they offered in a limited number at a lower price. The specs they released don’t advertise for too much power from this portable but it’s style and the fact that is portable together with the low price tag should compensate for the lack of power. And don’t get me wrong on the power issue, the 1 MHz bandwidth is still enough to cover your hobby needs. For me the only big disadvantage is the fact that it has only one channel, but it compensates with the ability of recording readings that you can later compare with the actual reading.

I would love to give you more details about this portable oscilloscope, but I have to wait until I can get my hands on the DSO nano. I’m currently waiting for Seeed to list it on their product page so i can place an order.

Bricogeek droped me an email to let me know they’re hosting a contest where participants are requiered to design a game with an Arduino board. You can use any version of the boards available but it must be playable so the user can interact with the game. You can submit your project, one per person, before the deadline shown on this page. There are some nice prizes waiting for you to win them so I suggest you start building . Good luck.

I received a kit from Protostack for review purposes, this kit is for the ATmega8 micro controller, and is probably the cheapest available with the shipping costs only 20$ worldwide,  so anybody can afford it.

After I assembled the kit, I also added a few extra parts, like series diode with the +5V supply and few capacitors for decoupling, filter choke for the AVCC, these are not mandatory, since the circuit works well without them(I tried), but its good to have it on the board.

After I changed the fuse settings to work with the external 16MHz crystal, I added a LED and resistor and a pin header, the circuit board has good quality solder mask and plating, this makes it easy to solder, it has large pads on the bottom, and no pads on the top layer, this way even when you use uncoated wires for connections which run over the pads on the top you don’t the risk short circuits.

Since the holes are trough plated, removing thicker wires like diode terminals can be tricky and you can rip out the hole plating, but even in this case the pad on the bottom remains intact, so this isn’t a problem. Although it would be better if no hole plating where used on the prototyping area.

The prototyping area is similar to a breadboard, the major difference is that the ATmega8 ports are nicely ordered, the supply and ground pins are connected together, and the programming pins are tied to a 10 pin header. I use the avr mk2 programmer which has only the 6pin header, so I had to make the adapter cable.

I also made a simple demo project with 1 LED, and 1 push button, in that project I will explain how to use the digital inputs and outputs, many people doesn’t pay attention to these simple peripherals and make typical design errors which will generate aleatory errors very hard to debug.

The demo project will get described in a future post.

ATmega8 kit from Protostack

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.

I finally got a new monitor on my desk, an Acer P223w. It looks great and I’m very happy with the performance, i mean its not top of its class but its worth the money i payed for it. I choose Acer after doing allot of research, of-course there were allot of other models and makes on the 22inch segment like Samsung that are slightly better but those were over my budget. Another reason i chose Acer for, its the Crystal Brite technology (CrystalBrite is Acer’s marketing name for high-gloss laptop screens, representing the latest in anti-reflective LCD screen technology). I own an Acer Aspire notebook, which has CrystalBrite display and it looks great, so i wanted the same technology on my desktop monitor.

Before i got the Acer P223w i was using a 17 inch CRT monitor(yeah i know, i should of got a new monitor some time ago) so you can imagine that i was truly impressed with the size and properties of the Acer. Here is a list with the main features of the Acer:

• Screen Size : 22″
• Resolution : 1680 x 1050
• Contrast Ratio : 2500
• Response Time : 5ms
• Connection : DVI, D-Sub

Acer actually build two versions of this monitor one with D-Sub(VGA) and one with DVI connector. I have the one with VGA, because at the store where i ordered the monitor they only had this version. But i don’t think the DVI version would of been any better, because most of the differences between DVI and VGA monitors are just numbers, nothing to be seen with your eyes.

The first thing i did when i powered it on, was to check for any dead pixels (i recommend you do this every time you buy an LCD display). The best way to check for dead pixels is to run a program called LCDtest (i attached a zip archive, so just click on the link to download it). What the program does is to display 5 colors on your screen(white, red, green, blue and black), this make spotting dead pixels really easy. So i ran the test and everything was ok, actually during the test i could see how nicely the monitor displays the black colour(very black).

My video card already detected it as a wide screen monitor and set the 1680 x 1050 resolution. Next thing to do was to find a nice High Definition wallpaper, i chose this nice mountain scenery. I’ve not seen bleeding issues like others report on various forums and sites, in fact i have no issue at all with the monitor. Even if it doesn’t have the 2 ms required response time for gaming, the monitor still displayed the games i tested without issues(Comand&Conquer latest versions, NFS Carbon).

Another great thing about the Acer P223W is the OSD menu, which is great. Other monitors have really complicated OSD menus, but not Acer. You can access 2 main OSD menus, the full menu by hitting the Menu button, or the E button (e comes from Empowering, another technology from Acer). So far i only use the empowering button, because i only change the display mode from Text to Movie sometimes, everything else the monitor adjusts automatically.

As a final word, the Acer P223W is a great monitor and definetely a must see on your shopping list. If you have a limited budget and you want to get great design and performance, this is a perfect choice.

About the “LOUD” part JBL is saying about this product on their website that it has “New 300mm CS Subwoofer Generation — This quality-built woofer offers double the power handing of the previous generation: Stunning 250/1000 W (RMS/peak)” I can only say, well done JBL it really is LOUD, imagine this waiting on the stop lights listening to your favorite tune so loud that the cars around you are listening to your music instead of theirs. I paid about 160 $ for the subwoofer and the installation kit and it fits quite nicely in my trunk with the big JBL logo printed on it. So far i had no problems , the sound is crystal clear, the bass its amazing, you can fell it trough the seats, trough the floor, its everywhere. I hope this is enough for those of you that were asking themselvs whether to buy this subwoofer or not. If not please post a question and i will be happy to answer it.

Here is the specifications on JBL CS1204T Car Subwoofer:

• Type Bass-Reflex Subwoofer Tube
• Power Handling, RMS 250W
• Power Handling, Peak 1000W
• Sensitivity (2.83V/1m) 90dB
• Frequency Response 35Hz – 200Hz
• Impedance 4 Ohms
• Dimensions (Diam. XL) 660mm x 346mm

The other reason why the default OS is not appealing to me is that there is a 2.3GB read only partition for the OS files and pre-installed programs. So you only have 1.4GB for your user files on the built-in drive. That wouldn’t really be such a big problem if you could free up some space, however even if you uninstall apps you don’t use, you can’t actually use any of that freed space because no data gets removed from the system partition. And if you install new apps it uses space on your user partition.

So that’s a no go. I installed plain debian on my EeePC and it works really nicely. All the apps I need (Firefox, Openoffice, Kopete, Konversation, KDevelop, , plus a full Qt/C++ development enviroment fits into 1.5GB so I have more functionality in much less space and much more flexibility. Got an extra 4GB SD card so I might put Windows on that (although windows is a bitch to install on removable storage).

Overall the EeePC is really awesome.. Even though it has a small screen, I find I’m using my main laptop less and less at home. There’s a huge benefit to having something you can easily carry around with one hand, has no moving parts, and can use in any place, and boots up super fast.

“The U600 is the slimmest slide phone ever, measuring an astonishing 10.9mm thickness. Yet it’s a high-spec phone featuring a 3 megapixel camera with flash and autofocus, and a fully-featured music player with expandable memory to replace your MP3 player. The only thing that may put some people off is the touch sensitive buttons – but sometimes you have to suffer a little to look good! A better buy might be the Samsung G600. Available in black, red, pink and blue”

And here is some Samsung U600 owner reviews gathered from the internet :

1. Great phone, very thin which is great and like the touch keys and camera quality is great a must buy phone for everyone. Has to be given and outstanding 5 stars.
2. didn’t like this phone – kept it for two days then exchanged it! battery is pretty rubbish, camera really good, but not worth keeping just for that. the key pad is way over senstive. i’ve been using samsung phones for years – defo not impressed with their latest, not as user friendly as past handsets.
   
3. the U900 is a great phone and i cant find any faults with it what so ever. everybody who says that is a bad phone is either just stupid or are stuck in the past and cant get used to todays technology!!! since i had my first samsung (D500) i have never had any other make of phone as i find samsungs very easy 2 use, stylish and modern. i would recomend this phone to everybody
4. Brilliant phone. Ive had it just over a week and i love it! I was originally going to go for an E900 but im so glad i went for the U600. Smooth, ultra slim slider (you wont believe how thin it is until you see it), sleek design and really excellent functions. Yes the battery life is not as good as other phones but that might be because you can’t put it down!! Touch sensitive keys are great but i think are better suited to women rather than men (sorry guys!!)I loved the motorola that i had before this and was worried about the change-over but i had nothing to worry about, i’ll definitely stay with Samsung for my next phone. Dont listen to the bad reviews – buy this phone, you’ll not regret it.
5. I’ve had this phone for a week now and I’m going to exchange it for either an N73 or k810i. The U600 main bad points are: 1. Terrible battery life. I need to charge it every day. Same usage on a K800 and I charged it every 3 days. 2. Texting is a nightmare. The predictive text software is awful. When given a list of possible words sometimes you have to scroll up, other times you have to scroll down. Why? 3. The touch sensitive buttons are great in theory but are not practical. Quite a number of times I’ve accidentally dialled someone while reading their text. Then you’ve got to quickly unlock the keypad and hang-up before the call is connected. This is beginning to become a real pain. ********** DO NOT BUY THE U600 **********
6. Just received my U600 and am pleased at the improvements Samsung have made to my previous phone the E900. At last on a Samsung, you can now use your own sounds for message alert, the ringer now supports vibrate and melody at the same time, messages are automatically saved and you now have a choice of clocks – which means you can go without the standard Samsung clock bar which is a permanent feature on earlier phones your mates may still have. For those – who I see from existing reviews – are gettting used to the touch-sensitive keys and moaning about inadvertently ringing numbers can I offer a workround which I used successfully on my E900 and which works on this phone. Simply go to your Call log and delete all ‘Recent Contacts’. Next time you brush over the phone key you will simply get a dialogue box on screen saying ‘Call log empty’. Note this does not affect your Missed Calls, Dialled Calls, Received Calls or Sent Messages – these are all still there in their own section to be accessed at any time you need them. I have added Call Log to ‘My Menu’ so you can easily jump to it and delete.Voila!
7. Very sturdy, the inside mech is metal. The slight wobble is not a weakness just movement in the metal track. Music player on mine does not see the 1gb mem card .. so no tunes will load – maybe I’m doing something wrong! can see then from the file app, but will only play 1 at a time, can’t mark multiple tracks … WHY? Everything else at this early stage looks pretty good to me – This one might last me a while, and believe me I’ve had a few!!!!!
8. Bought this phone from dialaphone to replace my beloved d500. The u600 is amazing! Everything is familiar from older samsung models, but can’t believe how thin it is. Camera is much much better than the d500, especially video recording. Screnn is amazing. I was worried about the touch sensitive keys, but tehr fine – don’t know what the fuss is about. I want to give this 6 out of 5!!!
9. Got this phone last week, have just got use to the sensitive touch and it works brilliantly. The photos taken with the 3.2mgp is sharp and clear. Battery can last me for 3 days if bluetooth not turn on. All symbols can be found are easily found by holding the # key. Software response is quick. Design is classy and elegant, with fantastic finishing. Samsung U600 is still the best compared to SE W880i, K550i, N95, N73, X820.
10. well well well.am i happy or what,got this phone today after swapping it from nokia 7390,i agonised for ages about swapping to this as i went off samsungs for a while.now they have sorted quite a few things out on their phones they have lured me back.i dont know what everyone is moaning about the touch sensitive keys,mine are perfect no jumping around all over the place like e900,equivalent to using the d900.the camera is very good with nice and clear picture quality,also no delay on shutter like some peoples complaints(i think it sounds like a faulty one)excellent sound quality and the main thing to me that converted me back is the fact you can now use your own tones for message alerts,not just the default dodgy ones.the battery has been quite good,lasted ages andi been messing round on it loads.Its slim,light and sexy and possibly gonna be a fave of mine.so buy it NOW !!!!!!

If you want my personal opinion, il give it to you again, There is only one bad thing to say about this phone: as usual Samsung fits it phones with not so good batteries as other phone manufacturers. So there is a down side, small battery life but that’s all.

Lets start by saying a few words about Linutop a small computer that runs from a USB key. Without internal hard drive, linutop is more robust. It offers a completely silent, low-power operation in an extremely small package. It comes with optimized software to access the Web and Digital Contents (Text, Photos, Music & Videos). Its low energy consumption its very low compared to a normal desktop computer, linutop only uses 5W of energy. A pack of Linutop + USB Key 1 GB Linutop

Is priced at $400. Click the Link to visit Linutop’s web page for full specs and ordering. Next lets talk NorhTec’s MicroClient Jr., an 11.5 x 11.5 x 3.5cm box based on SiS’ 200MHz SiS550 x86-compatible system-on-a-chip part. Like Linutop, the MicroClient Jr has no hard drive, but there’s a CompactFlash slot located on the front or a card containing the user’s preferred operating system – NorhTec will pre-install Linux if you like.

The unit has 128MB of on-board memory, plus a trio of USB ports – two on the front, one on the back – along with a PS/2 keyboard port, two serial connectors, 100Mbps Ethernet and a VGA port. MicroClient Jr. prices start from 120$ and go up according to your preferences. Click the Link for full specs and details.

Next on our list is Sumo ST166. Like Linutop, Sumo Technologies bases its ST166 box on an AMD Geode CPU, either a GX533 or an LX800. The 14 x 13 x 3.2cm unit crams in at least 128MB of memory and 64MB to 4GB of Flash storage. There are four USB ports and 100Mbps Ethernet, audio I/O connectors, and a VGA port. The Sumo’s average power consumption of 4.4 Watts makes it outstanding in its field.

Particularly suited for healthcare and industrial applications, the SUMO ST166 has zero ventilation requirements and is presented in a robust, sealed aluminum case. It has Support for Microsoft Windows XP Professional, Microsoft Windows XP Embedded, Microsoft Windows CE 5.0 and Linux operating systems. So its up to you what OS you will use with Sumo. Click the Link to visit Sumo’s web site.

The last small computer we will be reviewing in this article is ThinLinx. ThinLinx offers a more colorful option: the Hot-e. It’s offered in a couple of configurations both based on an AT91RM9200 SoC, itself derived from a MIPS ARM-compatible CPU, and available in lime, platinum or pink color schemes.

Again, an array of USB and serial ports are included, along with Ethernet for networking. And for power – one model, the HL100, supports Power Over Ethernet. ThinLinx also equips the boxes with CompactFlash and SD/MMC slots. The Debian ARM file system is pre-installed with the 2.6.12 Linux kernel. For full specifications click the Link.