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DealExtreme.com

       I think most people browsing my site are probably the sort of people who already know about DealExtreme.com; but if not, DealExtreme is a site that sells all manners of strange gadgets and devices direct from Chinese manufacturers, with free worldwide shipping. Well, the shipping cost is tacked onto the item price, naturally, but the prices for some of these items are simply beyond belief.

Of course, there is always a downside. From the time you place your order to the time it actually arrives on your doorstep can take anywhere from 3 weeks to 3 months (and yes, I personally have waited up to 3 months on a DX order). Customer support is also notoriously troublesome, with responses occasionally taking weeks. Though the one nice thing I can say about DX customer service is that if they send you the wrong item, in many cases they will send out a replacement and not ask for the other one back. I have gotten a few extra items this way in the past. Finally, one of the biggest problems with DX (at least in my mind) is the unacceptable delays in posting user reviews, or the reviews never getting posted in the first place. There are some absolutely terrible items sold on DX, and if they won't put up my reviews about them there, I will just have to post them on my own site.

On this page I will be covering a small fraction of the devices and items I have ordered from DX over the years. I'll only put up the ones I think there will be some interest in, as many of the things I order are simply novelties that have no practical purpose. I will be putting items and devices up here in no particular order, and expect to regularly add to this page as I order new things and get a chance to play with them.

Mini Bluetooth (16229)

16229

       For $2.17 (in bulk orders), SKU 16229 is the cheapest USB Bluetooth adapter I am personally aware of (that actually works). I have ordered somewhere in the neighborhood of 20 of these devices for my various projects and machines here, and they have been of consistently...usable quality. These are by no means high-quality devices, but they serve their purpose and rarely give me issues.

These are the adapters which most of the nodes ran during the creation and testing of bt_rng. I was also able to confirm the functional range of this adapter to be 30 meters during the Host XR range test. They are based on a low-end version of the Cambridge Silicon Radio chipset:

bash:~# hciconfig hci0 version revision
hci0:	Type: USB
	BD Address: 00:11:67:6A:XX:XX ACL MTU: 310:10 SCO MTU: 64:8
	HCI Ver: 2.0 (0x3) HCI Rev: 0xc5c LMP Ver: 2.0 (0x3) LMP Subver: 0xc5c
	Manufacturer: Cambridge Silicon Radio (10)
	Unified 21e
	Chip version: BlueCore4-ROM
	Max key size: 128 bit
	SCO mapping:  HCI
Note that this device (and all of the DealExtreme Bluetooth adapters, for that matter) uses the BlueCore4-ROM version of the CSR chipset, which means they lack the external flash storage that is required for making permanent changes like replacing the firmware or writing a new MAC address to the device. This does limit your capability a bit, but these adapters are just fine for scanning. If you want to do more advanced work, like sniffing PINs, you need an adapter with BlueCore4-External, like the AIRcable Host XR.

As a side note, SKU 12696 appears to be an identical clone to SKU 16229, just at a higher price point. As the capabilities of these two adapters are identical, they are both good choices for basic Bluetooth research...but since one costs more than double the other, the choice between them is pretty obvious.

Mini Bluetooth (11866)

       Now, above I mentioned SKU 16229 was the cheapest working Bluetooth adapter I am aware of. That is because DX also sells another adapter with the same name under SKU 11866 for $1.80 ($1.13 in bulk); this adapter is not the same as SKU 16229 and is in fact complete garbage. I ordered 10 of SKU 11866 once I saw how cheap they were, and not only did they all come with the same default MAC address (making them useless for many tasks), but one of them actually got so hot when plugged in that I could smell plastic melting. These two devices are identical externally, but when you check the device information you can see it isn't the same:
bash:~# hciconfig hci0 version revision
hci0:	Type: USB
	BD Address: 00:15:83:15:A1:DA ACL MTU: 672:4 SCO MTU: 48:1
	HCI Ver: 2.0 (0x3) HCI Rev: 0xc5c LMP Ver: 2.0 (0x3) LMP Subver: 0xc5c
	Manufacturer: Cambridge Silicon Radio (10)
	Build 0
	Chip version: BlueCore01a
	Max key size: 0 bit
	SCO mapping:  PCM
BlueCore01a is an ancient version of the CSR chipset, and is worthless for almost anything you could possibly want to do with it. I have also heard some reports that recent batches of this SKU are using the Broadcom BCM2210 chipset, which is marginally less terrible, but doesn't have the software support that CSR enjoys. Unless you just want to scan for remote devices, please don't buy SKU 11866.

Class 1 BT Dongle (14484)

       SKU 14484 is a cheap knock-off of the Linksys BT100, and even for a knock-off, it is absolute garbage. It's nothing more than a standard Bluetooth adapter with a thin piece of wire soldered (poorly) to the internal antenna. It is certainly not Class 1, and if anything, it seems like the "antenna" they added hinders performance. Take note of the expert LED mod they did here as well:

Garbage

This is one of the first items that DX refused the images and review I submitted for it, so I wanted to make sure I got this one on the site. At $8 it is one of the worst Bluetooth adapters you can buy on DX. Please never buy this item for any reason.

Mag Stripe Reader (17726)

17726

       As of this writing, SKU 17726 is unfortunately no longer available on DX. For $20 it is a decent quality USB magnetic stripe reader that appears as a USB HID to the host OS. Well, that is the idea anyway. I found that this doesn't always work as expected under Linux, and the reader only seems to work randomly. This is an exceptionally annoying problem, but I have never found any workable solution and the kernel's error messages are not terribly helpful. I suspect the internal firmware on this device doesn't comply 100% with the USB HID specifications, and that a kernel driver would need to be made/modified to accept this device as HID based on it's USB VID/PID, regardless of what it appears to be. But I have yet to dive into kernel hacking so I haven't been able to implement anything. The only output from the kernel when this device is connected (and not working) is:

usb 6-2: new full speed USB device using uhci_hcd and address 2
usb 6-2: config 1 interface 0 altsetting 0 has 2 endpoint descriptors,
different from the interface descriptor's value: 1
usb 6-2: configuration #1 chosen from 1 choice
input: HID f725:f834 as /devices/pci0000:00/0000:00:10.1/usb6/6-2/6-2:1.0/input/input21
input: USB HID v1.10 Keyboard [HID f725:f834] on usb-0000:00:10.1-2
drivers/hid/usbhid/hid-core.c: ctrl urb status -75 received
This device has a small DIP switch on the bottom which is used to toggle optional post-processing of the ASCII card data. DIP 1 toggles LF after outputting the string, and DIP 2 toggles pre/postfix control characters (; and ?, respectively). The third DIP is supposed to switch the reader between tracks 1/2 and 2/3, but apparently doesn't actually do anything.

All in all, this is a decent buy for an easy to interface mag reader, but the fact it only works reliably under Windows is a pretty big drawback. It is also rather large for such a relatively simple device, but that is not nearly as big a problem.

USB to RS232 Dongle (5859)

5859

       Not a whole lot to say about this one, other than that it is a very handy tool to have around. For under $4, SKU 5859 it's worth keeping in your parts box just in case you need to quickly interface a serial device with one of your machines. This device is obviously designed for machines that lack serial ports, but even on machines that do have serial ports, I find it is more convenient to simply use this device in the front USB ports than reach around the back to the serial.

I have also had situations where some serial devices wouldn't work on my actual serial port, but worked through this. For example, I have had problems getting the AIRcable Mini to talk over an actual serial port, but it has no problem through this adapter.

This device is a particularly good buy as it uses the very well supported Prolific PL2303 chipset, which will work in basically any modern OS right out of the box. It also supports all RS-232 signals, such as RTS/CTS and DTR/DSR. A lot of cheap adapters leave these out to cut costs, so it is pretty impressive that it has them in. I know some people have also modified this device to work with TTL-level signals by disabling the MAX232 chip inside.

Update: I have read some reports that new versions of this device are shipping with the CH341 chipset rather than the more common PL2303. I have not been able to personally verify the new adapters have switched chips, but at least CH341 chipset is fairly well supported if it has. So if your only concern is getting an adapter that works on all of your computers, you will still be fine, the only problem you might have is if you need a PL2303 device specifically.

Dummy SIM Cards (16159)

16159

       SKU 16159 is a 10 pack of dummy SIM cards, which are invaluable when working with cell phones, as many brands of GSM phone won't start without a valid SIM inserted. During my Bluetooth research I picked up dozens of cheap phones off of eBay to test with, so luckily they are a pretty good value at just under $4 a pack.

Keep in mind though that not all phones require a SIM to operate. For example, in my experience most Nokia phones don't require them, while Motorola phones usually do. Also, if the phone you are working with is locked to a particular carrier, then these alone won't get the phone working. The phone will start with the dummy SIM, but when it tries to connect to the cell network it will fail (unless, perhaps, you live in China where these SIMs were pulled from). To get past the carrier lock, you will need...

i-SmartSim Unlocker (12167)

12167

       SKU 12167 is a very small device that piggy-backs onto a SIM card and fools the phone into thinking it is for the carrier the phone is locked to. You can use this device to perform a physical unlock on your phone (say for example, if you wanted to use the iPhone on T-Mobile), or you can combine this with SKU 16159 to get even carrier locked phones to boot up without the original SIM. The DealExtreme page says this device is designed primarily for Nokia phones, but personally I have been able to use it on phones from a number of different manufacturers without any issues.

To install this device you need to cut out a little notch on the top part of the SIM, as shown in the picture above. This area of the SIM is simply plastic, and doesn't contain the actual SIM chip, which is located on the opposite side of the gold contacts. There is no danger of cutting too far into the SIM and destroying it, so don't be afraid to cut out a little more than I did. I used a Dremel to cut out the square, but if you have snips small enough you should be able to get in there, or maybe use a small hobby razor knife. I would suggest tacking the unlocker and the SIM together with some very small drops of cyanoacrylate adhesive (AKA, Super Glue or Krazy Glue) around the extreme edges of the SIM. You need to be very careful not to put too much on, or else it may overflow onto the actual SIM contacts under the unlocker, in which case you are in some real trouble. If you don't glue them together, it makes it much more difficult to insert and remove the SIM/unlocker, though not impossible.

I have never personally found a phone this didn't work on, though I am told newer handsets might have issues (for which DX sells an updated version of this product). While this should certainly not be taken as a compatibility list in any shape or form, I can at least confirm the i-SmartSim works perfectly on the following phones:

       Ericsson T39m
       LG CU575
       Motorola Razr V3
       Nokia 2600
       Nokia 6555b
       Samsung A737

100g Digital Scale (15002)

15002

       SKU 15002 is an extremely accurate digital scale at an incredible price ($10.87 as of this writing), perfect for weighing small objects and chemistry work. This scale features a maximum capacity of 100g, with a precision of 0.01g. The scale comes with a fake-leather carrying case that protects it pretty well, and there is a plastic snap-on protector for the actual weighing platform.

If you are going to get this scale and want to make sure it is as accurate as possible, you should also order the 100g calibration weight (SKU 15761). Even if the scale is perfectly accurate when you receive it (which is already unlikely as movement tends to knock it out of precision), with time and temperature changes the accuracy of the scale will begin to drift. To calibrate the scale, hold the "On" button until "0" flashes and place the calibration weight on the scale; after a few seconds the weight should peg at "100.00" and stop flashing. Once calibrated, you should verify the calibration of the scale every so often by simply placing the calibration weight on scale and verifying it still reads "100.00".

If you need higher capacity, this same scale is available in models all the way up to 300g. After that, there is a trade off between accuracy and capacity. Scales above 500g usually only offer 0.1g resolution. If you are looking for very high resolution, you may want to check out SKU 10515, which appears to be the highest resolution scale currently offered on DealExtreme.