Reverse engineering the die of a ULN2003 transistor array


We’re no strangers to looking at uncapped silicon. This time around it’s not just a show and tell, as one transistor form a ULN2003 chip is reverse engineered.

The photo above is just one slice from a picture of the chip after having its plastic housing remove (decapped). It might be a stretch to call this reverse engineering. It’s more of a tutorial on how to take a functional schematic and figure out how each component is placed on a photograph of a chip die. Datasheets usually include these schematics so that engineers know what to expect from the hardware. But knowing what a resistor or transistor looks like on the die is another story altogether.

The problem is that you can’t just look at a two dimensional image like the one above. These semiconducting elements are manufactured in three dimensions. The article illustrates where the N and P type materials are located on the transistor using a high-res photo and a reference diagram.

If you want to photograph your own chip dies there are a few ways to decap them at home.

Hackaday Staff Update


It’s been just over three weeks since Supply Frame bought Hackaday and a lot has been going on. Almost all of it has been behind the scenes as we make our way through the scaffolding that was built up over the years to run the site. I’ll share more on that as things develop. But now I’d like to introduce you to the staff.

We’ve actually had a staff page for about a year but I’m not sure it was ever announced. Check out the Staff roll call to see a picture and bio of each of our team members. [Brian Benchoff] and I make up the editorial team. [Eric Evenchick] joins us once again as a writer. And over the last couple of weeks we hired [Mathieu Stephan] (aka Limpkin), [Josh Marsh], and [Michael Ciuffo] (aka ch00f). The six of us come from a wide range of backgrounds. We have interests and skill sets that complement each other, and as we get used to working as a team this will equate to better features and more original content. Please join me in welcoming the new writers, and long live Hackaday!


Electronic wedding attire for a geeky wedding

In the past we featured many projects that were used at [Bill] and [Mara]‘s wedding. However we forgot the most important thing: their electronically enhanced clothes.

As you can see from the picture above, the wife opted for LEDs while the husband preferred Electro Luminescent (EL) wires/panels. The ATtiny based platform LilyTiny was picked to control all the LEDs, and charlieplexing was implemented as only 4 IO pins were available. Animations were made using Vixen and exported via a python script.

To power the EL wires, [Bill] hacked a Sparkfun EL battery pack/inverter. He removed the shell and took out the inverter part, reverse engineered the design enough to figure out how to bypass the onboard microcontroller that generated the on/off/blink function. Finally, he 3D printed enclosures to pack the electronics with one Li-Ion battery pack. A boost regulator was used to supply the 12v required by the EL panel power supply.

Don’t forget to also check out their centerpieces and wedding invitations that we previously featured.

Turning anyone into a casuality


EMTs and other first responders don’t just sit around waiting for a disaster to happen. If they need to train for a disaster – environmental, terrorist, or otherwise – they put together a mass injury simulation, or their version of a war game. As you can imagine, coordinating one of these simulations is a nightmare, but [David] came up with a way to simulate a casualty with a few XBees, a Parallax Propeller, and a few RFID cards.

This triage training simulator consists of an ‘acting coach’ on each simulated victim that includes a speech-to-text module that speaks instructions into the actors ear, a pulse simulator and a readout for vital signs that correspond to twelve major injuries. When an EMT triages a victim, they swipe an RFID card for each medical procedure they perform – intubating is one card, while a bandage is another – and all this is sent back to the coordinator’s tablet.

The coordinator has direct control over each of the actors through a two-way radio link, and can initiate changes in each victim, monitor a paramedic’s responses, and “escalate” the situation by setting off another simulated bomb.

All this is created with off-the-shelf hardware, vastly reducing the cost of this type of training device. An amazing application of what we usually consider to be just robot parts, and we’re happy for [David] to share it with us.

[Read more...]

Change the TV channel over IP


[Mustafa Dur] wrote in to tell us about his hack to control the television with a smartphone. Now the one-IR-remote-to-rule-them hacks have been gaining popularity lately so we assumed that’s how he was doing it. We were wrong. He’s using his satellite receiver to provide the Internet connection. It pushes commands to his LG 47LH50 TV which has an RS-232 port.

The image above is the back of another LG television (it came from a forum post about controlling the TV with a PC). [Mustafa] is using a Dreambox DM800 satellite receiver which also has a serial port an he can telnet into it. He searched around the Internet and discovered that it should be possible to connect the two using a null modem cable. His initial tests resulted in no response, but a tweak to the com port settings of the box got his first command to shut off the television. After a bit of tweaking he was able to lock in reliable communications which he made persistent by writing his own startup script. From there he got to work on a Python script which works as the backend for a web-based control interface.

If you want to find out what else you can do with this type of serial connection read about this hack which used a script to try every possible command combination.

Turning a tiny Linux box into a synthesizer


For all the cool things the Raspberry Pi, BeagleBone, and other low-power Linux boards can do, there’s one thing we haven’t seen much of: creating music with software synthesizers. Yes, soft synths have been around for ages now, but compiling them for these ARM boards is something we haven’t seen much of (to say nothing of the Linux audio system). Luckily, [Paul] and [Trev] have put together a tutorial for making synthesizers on these small Linux boards using Csound, the premier audio programming language for Linux.

[Paul] and [Trev] have already put together a few Csound instruments that include a Vangelis-inspired synth, a Lorenz Strange Attractor FM synth, a drum machine, and a classic monophonic style synth. All these instruments are ready to play on a Raspi or BeagleBone and we’re sure we’ll see a few more applications of this great tool for creating musical instruments as more musicians are turned onto these small Linux boards.

Rock solid PCB mill built at home


Let’s all slow clap for [Daniel Taylor] who, after a long journey, got his home built PCB mill up and running with remarkable precision. That’s 10 mil traces with 0.5mm pitch pads. We’re impressed! The board will be used for breaking out the connections of an LCD screen he has on hand.

After seeing a CNC project as yesterday’s Fail of the Week it’s nice to look in on one like this that does some amazing stuff. In fact, [Daniel's] creation has been working for months already. The link above is the project log he kept while hacking, tweaking, and retrofitting his rig to get the level of precision he was after.

Improvements include swapping out drawer slides for proper linear bearings and completely reworking the Z-axis along with a motor upgrade. For those that aren’t fans of the reading (how did you make it this far into this feature?) you can take a quick look at his image gallery which includes captions.