Hacked Gadgets Forum

August 22, 2014

DIY Component Tester – Transistor, Capacitor, Inductor, Resistor Meter

at 8:05 pm. Filed under Cool Gadgets, DIY Hacks

 

If you are looking for a DIY meter project have a look at this DIY Component Tester (translated),  it tests Transistors, Capacitors, Inductors and Resistors. It is AVR based and is very flexible, in most cases you can just jam in a device and press the button to analyze the device.

“Automatic detection of NPN and PNP transistors, N-and P-channel MOSFETs, diodes, thyristors, inductors, triacs, resistors and capacitors.
Measure ESR with a resolution of about 0.01 ohms
Automatic calculation and display of the pins of the component under test
Detection and display of protection diodes for transistors and MOSFETs
Determination of the gain and the base-emitter forward voltage at transistors
Measuring the gate threshold voltage and gate capacitance of MOSFET
Self calibration process to improve accuracy”


August 21, 2014

MESR-100 ESR Meter Review and Teardown

at 5:25 am. Filed under Reviews

MESR-100 ESR Meter Review and Teardown_8063

 

I wanted an in-circuit ESR meter (equivalent series resistance meter) to aid in determining the condition of  electrolytic capacitors without the need of desoldering them first. When capacitors fail you will often have some signs of failure such as bulging of the capacitor top. Starting in approximately 2002 and continuing till about 2010 there was a glut of high failure rate capacitors on the market which found their way into everyday items such as PC power supplies, monitors, motherboards etc. These devices would test fine after manufacturer and continue to work for the consumer for many years but fail prematurely, often in as little as one year.

I purchased a MESR-100 Meter from eBay for around $55 USD shipped to my door in Winnipeg (Canada). The meter came well packaged in a retail box, this is a nice change from many other items from China that are simply wrapped in bubble wrap and stuffed into a padded envelope. Inside the box was the meter, two short meter leads and a manual. Pressing the red power button for a few seconds powers the meter, it is ready to use after about 3 seconds. The display is a backlit LCD display, it does appear that the backlight is on all the time. The display is nice and bright and has a good viewing angle, there are two hot spots near the bottom of the display which is probably due to the location of the backlight LEDs but it doesn’t effect display readability. 

The meter has 3 modes, autoranging, 0 to 1 ohm, 1 to 10 ohm and 10 to 100 ohm. The modes can be cycled through by pressing the mode range button. The meter can be zero calibrated by shorting the leads and pressing the zero button. All of the buttons need to be pressed for about half a second before they are recognized, a quick tap isn’t usually sufficient. This button sensitivity could be improved but other than powering the unit on I am thinking it will live in automatic mode until it is switched off after use anyway.

The display has lots of useful information. There is a battery indication, mode indication, large resistance reading and some smart text under the reading that indicates some criteria of when the capacitor under test would be considered good. There is also a chart on front of the meter but the automatic text output during the reading is very convenient.

The meter is powered by a PIC18F24K20 microcontroller, there are also some unpopulated areas which suggests that there might be a more advanced version of this meter available. The other main IC on the board is a TI LMV824 Precision Low Voltage Operational Amplifier. The case also has some indications of a second version, directly under the 3 existing buttons you can see a space for 3 more, it is obvious from the inside of the case and is also slightly visible when looking at the front of the meter.

 The meter case could be improved, it is cheap feeling and the tilting bail works but feels like it will break in time with normal use. The display protection is quite thin and you can feel it deform easily with a light press. The cutout on the side for the external USB jack is not centered very well adding to the low quality look and feel of the case. I wouldn’t have this thing unprotected in a toolbox since the case would be prone to damage in that scenario.

The PCB is of high quality, it is a single side SMD loaded board. The PCB has an immersion gold finish which should keep it corrosion free for a long time. The solder joints look good, there is some hand soldering of the leads that run to the battery compartment and the front test jacks, these could have been soldered better but they are adequate, it was nice to see some heavy wire going to the banana jacks on the front but their placement made it cumbersome to re-assemble the meter since the plugable area is between where the leads are soldered into the board and the jack, this means you need to bend the wires around the plugable area while reassembly. There is one bodge on the board, it looks like a lower profile capacitor was originally specified but when it was manufactured the capacitor that was used was slightly too tall so it was soldered in and allowed to lay against the PCB for clearance. You can see it in the pictures below and in the video.

The reading are believable but I don’t have any other test equipment on hand that can confirm if the ESR readings are accurate, the manual does indicate that the meter is accurate to 1% and 2% depending on the range you are in. The meter states that it uses a 100KHz frequency to test the capacitors using a sign wave and this was confirmed on the scope, the test voltage is around 150mV.

Overall I am pleased with the meter, for the price the functionality. If you are looking for a meter in this price range I would recommend it.

You can see full sized images here on Flickr.

 

 

MESR-100 ESR Meter Review and Teardown_8132

 

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August 20, 2014

Military & Aerospace Electronics Magazine – Free Subscription

at 9:42 pm. Filed under Other

Military & Aerospace Electronics Magazine - Free Subscription

 

If you are an electronics professional there is no way to keep up with the latest developments in electronic technology than to read what large military budgets are able to dream up. You can subscribe for the free print or digital edition of Military & Aerospace Electronics Magazine in the Hacked Gadgets free technical magazine store. You may want to use your alternative email address when signing up though to be able to separate publication emails from your everyday emails. Hacked Gadgets does receive a fee when a subscription is made so we appreciate your support when signing up to your free subscriptions through us.

Military & Aerospace Electronics editorial covers topics such as Navigation/Guidance, Avionics, Missile Systems, Communication Systems, Electronic Warfare, Simulation/Training Systems, Unmanned Vehicles, Nanotechnology, Biometrics, Homeland Security, Shipboard Electronics, Reconnaissance Equipment and other relevant topics to military professionals in organizations such as the Department of Defense (DOD), NASA, FAA, CIA, FBI, NSA, Defense Contractors, Prime Contractors, Subcontractors/Integrators, Electronics Manufacturers, Defense Systems Vendors, and R&D, among others.”

 

 


August 19, 2014

Binary Wrist Watch

at 9:31 pm. Filed under Cool Gadgets, DIY Hacks, Electronic Hacks

 Binary Wrist Watch

 

Check out this great Binary Wrist Watch. It’s a true watch for the geek since most won’t be able to read it!

Via: Dangerous Prototypes

“The time setting mode can be entered by holding the left button for two seconds. After that the display is blanked and the time can be set bit by bit by switching through the bits by pressing the left button. If the bit is to be set, the right button has to be held down for one second. The watch automatically enters normal display mode after the last bit has been set (once you’ve gone through all the bits).”

August 16, 2014

Mini MAME Cabinet

at 9:16 pm. Filed under Cool Gadgets

 Mini MAME Cabinet_2

 

If you are going to be building a MAME cabinet, you should have a look at the Mini MAME Cabinet that Greg Kennedy built for some tips. He built this thing from scratch and kept the costs down, using some older electronics was a great way get some use out of the hardware that might not have had a use otherwise. The hand made cabinet turned out very nice, at a glance you can’t tell that it was home made.

 

Hardware

Complete hardware specs for this build:
  • Intel 1.3ghz Pentium 4
  • 128mb RDRAM
  • 256mb CF card, CF< ->IDE adapter
  • 250W PSU
  • PCI: S3 Virge DX, 4mb VRAM
  • PCI: Creative (Ensoniq) Sound Blaster PCI
  • Monitor: IBM PS/1 13″ CRT VGA (max res: 800×600)
  • Speakers: cheap no-brand PC speakers

 

  • MDF: $35
  • Screws and wood glue: $15
  • Joysticks, buttons, T-Molding: $30
  • Plexiglass scraps: $10
  • Paint: $15
  • Printing: $5
  • Fluorescent lamp: $7
  • Hinges, lock, misc. fasteners: $30″

 

Mini MAME Cabinet

 

 

 

 


August 14, 2014

BadUSB – Hacked USB Drive to Black Hat 2014

at 9:53 pm. Filed under Complex Hacks

 USB_flash_drive

 

You probably have a handful of USB drives around your computer, they are useful and ubiquitous. After reading this article and watching the video below you might think twice before plugging in a found USB drive or one from a casual acquaintance. USB was dreamt up way back in 1994 and has gone through many versions since then. USB has a simple 4 pin contact, two for power and 2 for bi-directional data transmission. Even though it has a very simple electrical interface there are many types of devices that can be plugged in and run over USB, you can see the 2 hex digits in the table below which represent all of the USB class devices (via). The device passes this class number to the computer when powered to allow the computer to understand what has been plugged in.  

Karsten Nohl and Jakob Lell from SR Labs did some reverse engineering to a simple USB thumb drive. They have created a thumb drive that can power up as a class 08h mass storage and display the files. It can then change to a class 03h device which is a HID such as a keyboard. Now the thumb drive can easily perform some keystrokes which can do things such as open a shell window and perform any commands you like.

If you think plugging in a phone into your computer to charge it is harmless guess again. At 24:46 in the video a properly setup phone is plugged into the USB port and with no obvious changes all of your Paypal passwords are now being sent to the hackers. This demonstration software has been released for security professionals to ensure they are protected against this attack.

 Of course it was just a matter of time for this exploit to be performed, much of the controller chips are fully documented and easily available.  There are also lots of fake drive manufactures who have hacked their own firmware to allow them to have incorrect size information to be displayed to allow drives with small amounts of NAND memory to show up and act as a huge drive.

I can see all of the large manufactures with solid supply chains start to sell devices that have their driver firmware stored in ROM or in EEPROM memory that has a write fuse blown to prevent future writing of the firmware. We see this in microcontrollers and don`t think twice about it.

It is now up to us, the consumer, to demand with our purchasing dollars that devices that are sold to be free of this type of attack.

 

 

 

USB Device classes include:

Class Usage Description Examples, or exception
00h Device Unspecified Device class is unspecified, interface descriptors are used to determine needed drivers
01h Interface Audio Speaker, microphone, sound card, MIDI
02h Both Communications and CDC Control Modem, Ethernet adapter, Wi-Fi adapter
03h Interface Human interface device (HID) Keyboard, mouse, joystick
05h Interface Physical Interface Device (PID) Force feedback joystick
06h Interface Image Webcam, scanner
07h Interface Printer Laser printer, inkjet printer, CNC machine
08h Interface Mass storage (MSC or UMS) USB flash drive, memory card reader, digital audio player, digital camera, external drive
09h Device USB hub Full bandwidth hub
0Ah Interface CDC-Data Used together with class 02h: communications and CDC control
0Bh Interface Smart Card USB smart card reader
0Dh Interface Content security Fingerprint reader
0Eh Interface Video Webcam
0Fh Interface Personal Healthcare Pulse monitor (watch)
10h Interface Audio/Video (AV) Webcam, TV
DCh Both Diagnostic Device USB compliance testing device
E0h Interface Wireless Controller Bluetooth adapter, Microsoft RNDIS
EFh Both Miscellaneous ActiveSync device
FEh Interface Application-specific IrDA Bridge, Test & Measurement Class (USBTMC), USB DFU (Direct Firmware Update)
FFh Both Vendor-specific Indicates that a device needs vendor-specific drivers

 

 

August 13, 2014

Reverse Engineering a NAND Flash Device Management Algorithm

at 7:50 am. Filed under Complex Hacks

Reverse Engineering a NAND Flash Device Management Algorithm

 

When your hard drive electronics dies you can ship your hard drive to a recovery company and for some serious dollars they will connect your spinning disks to known good electronics and retrieve your data. That’s fine when your drive electronics are mounted on a removable PCB in a large chassis. Now think of the same issue when talking about the embedded system inside an SD card which handles the reading and writing operations between the NAND flash and the outside world. The size of the device makes this a challenging problem. Joshua Wise was forced to look into this issue when his SD card was accidentally smashed. Interfacing with the flash was just one of the hurdles, the first issue was physically connecting to the pins on the damaged device. One of those great Schmart boards came to the rescue for that. Joshua wrote a number of programs to assist him to interface with the flash.

Via: Electronics Lab

 

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