Posts with «teardown» label

The Other Kind of Phone Hacking

While it’s true that your parts bin might have a few parts harvested from outdated devices of recent vintage, there’s not much to glean anymore aside from wall warts. But the 3×48-character LCD from [Kerry Wong]’s old Uniden cordless landline phone was tempting enough for him to attempt a teardown and reverse engineering, and the results were instructive.

No data sheet? No problem. [Kerry] couldn’t find anything out about the nicely backlit display, so onto the logic analyzer it went. With only eight leads from the main board to the display module, it wasn’t likely to be a parallel protocol, and the video below shows that to be the case. A little fiddling with the parameters showed the protocol was Serial Peripheral Interface, but as with other standards that aren’t exactly standardized, [Kerry] was left with enough ambiguity to make the analysis interesting. Despite a mysterious header of 39 characters, he was able in the end to drive the LCD with an Arduino, and given that these phones were usually sold as a bundle with a base and several handsets, he ought to have a nice collection of displays for the parts bin.

With how prevalent this protocol has gotten, [Kerry]’s post makes us want to get up to speed on the basics of SPI. And to buy a logic analyzer too.

Filed under: misc hacks, teardown

Before Arduino There was Basic Stamp: A Classic Teardown

Microcontrollers existed before the Arduino, and a device that anyone could program and blink an LED existed before the first Maker Faire. This might come as a surprise to some, but for others PICs and 68HC11s will remain as the first popular microcontrollers, found in everything from toys to microwave ovens.

Arduino can’t even claim its prominence as the first user-friendly microcontroller development board. This title goes to the humble Basic Stamp, a four-component board that was introduced in the early 1990s. I recently managed to get my hands on an original Basic Stamp kit. This is the teardown and introduction to the first user friendly microcontroller development boards. Consider it a walk down memory lane, showing us how far the hobbyist electronics market has come in the past twenty year, and also an insight in how far we have left to go.

The Basic Stamp 1. A Simple circuit with just a microcontroller, an EEPROM, crystal, and brownout circuit.


The Basic Stamp kit on my workbench was made in 1993, and sold for a suggested retail price of $139 USD. Adjusted for inflation, this is nearly $230 in 2015 dollars. What do you get in the Basic Stamp starter kit? A single stamp, a programmer cable, and a surprising amount of documentation.

The Basic Stamp is an extremely minimalist board that does just enough to blink an LED, read a button, or drive an LCD. In the official documentation,  there are only a handful of parts: a microcontroller, an EEPROM with a few bytes of memory, a crystal, and a voltage regulator.

The PIC16C56XL is the brains of the outfit, featuring 1.5kilobits of Flash memory and 25 bytes of RAM. By modern standards, it’s tiny; the closest modern analog would be the ATtiny10, itself not a very recent chip. Microchip’s smallest and newest chip is the PIC12LF1522, featuring twice as much Flash and ten times the amount of RAM. We’re dealing with an old microcontroller when using the Basic Stamp

Like the Arduino, it was encouraged to use the Basic Stamp in product design.

Other components include a 93LC56 serial EEPROM. beside that is a 4MHz regulator, a 5V linear regulator, and a transistor and a few resistors for the ‘brown out’ circuit. Power is provided by a 9V battery connector soldered onto the board.

The electronic design of the Basic Stamp is simple, yes, but there’s a method to the madness. The code you write for the Basic Stamp is stored in 256 bytes of the EEPROM. This code is read by a PBASIC interpreter on the PIC, dutifully following commands to blink a LED or display a character on an LCD. No user code is actually stored on the microcontroller.


How about the programming environment? That’s a single executable running in a DOS shell. The system requirements are only, an IBM PC or compatible, DOS 2.0+, 128k of RAM, and a disk drive. Meager requirements, but this is not something that will run on your modern Windows workstation; it requires a proper parallel port.

For an IDE, the Basic Stamp editor is comparable to earlier Arduino IDEs; Alt+R runs the program on the Stamp connected to the computer, Alt+L loads a program, Alt+S saves a program, and Alt+Q quits the editor.

The BASIC language implemented on the PIC is minimal, but it does everything you would expect; individual pins can be set as input and output, buttons are debounced, and PWM functions are baked into the language.

An ad for the Basic Stamp. From High Tech Entrepreneur, October/November 1993. Ads had text in the past.


The Basic Stamp is now regarded as a slow, inconvenient artifact from the past. No one uses it, and the only place you’ll find one is in the back cabinet in a physics or EE classroom. This is an incredible disservice to a still-impressive piece of technology, and looking back at the Basic Stamp with our modern expectations is an incredible bias.

There were microcontroller development platforms before the Basic Stamp, but these were engineering tools, and expensive compared to the Stamp. Development platforms for the electrical hobbyist were around after the stamp, too: the Micromint Domino packed an entire development platform into a rectangular brick of plastic. None of these designs could match the popularity of the Basic Stamp despite the platform’s shortcomings.

The Arduino receives a lot of hate. Detractors say it’s too high-level for proper embedded programming, not high-level enough for a modern workflow, is based on old, obsolete chips, doesn’t have the features of modern ARM microcontrollers, and the IDE is a mess. Despite an even less capable IDE, meager memory, and a slow processor, the Basic Stamp proved incredibly popular. The fact that you could pick up a Basic Stamp development kit at any Radio Shack probably didn’t hurt it’s popularity, either.

Now, with our fancy IDEs, mbed microcontrollers, powerful ARMs, and huge libraries, the ease of use of the Basic Stamp has still not been equaled. It may be slow, outdated, but all of us owe a great debt to the Basic Stamp for introducing an entire generation to the world of embedded programming, microcontrollers, and electronics tinkering.

Filed under: classic hacks, Featured, Microcontrollers

Hackaday Links: July 19, 2015

Everybody needs an external USB drive at some time or another. If you’re looking for something with the nerd cred you so desperately need, build a 5 1/4″ half height external drive. That’s a mod to an old Quantum Bigfoot drive, and also serves as a pretty good teardown video for this piece of old tech.

The Woxun KG-UV2D and KG-UV3D are pretty good radios, but a lot of amateur radio operators have found these little handheld radios eventually wear out. The faulty part is always a 24C64 Flash chip, and [Shane] is here to show you the repair.

Last year there was a hackathon to build a breast pump that doesn’t suck in both the literal and figurative sense. The winner of the hackathon created a compression-based pump that is completely different from the traditional suction-based mechanism. Now they’re ready for clinical trials, and that means money. A lot of money. For that, they’re turning to Kickstarter.

What you really need is head mounted controls for Battlefield 4. According to [outgoingbot] it’s a hacked Dualshock 4 controller taped to a bike helmet. The helmet-mounted controller has a few leads going to another Dualshock 4 controller with analog sticks. This video starts off by showing the setup.

[Jan] built a modeling MIDI synth around a tiny 8-pin ARM microcontroller.  Despite the low part count, it sounds pretty good. Now he’s turned his attention to the Arduino. This is a much harder programming problem, but it’s still possible to build a good synth with no DAC or PWM.

Filed under: Hackaday Columns, Hackaday links

Reverse-Engineering a Superior Chinese Product

It makes an Arduino look like a 555.  A 364 Mhz, 32 bit processor. 8 MB RAM. GSM. Bluetooth. LCD controller. PWM. USB and dozens more. Smaller than a Zippo and thinner than corrugated cardboard. And here is the kicker: $3. So why isn’t everyone using it? They can’t.

Adoption would mandate tier after tier of hacks just to figure out what exact hardware is there. Try to buy one and find that suppliers close their doors to foreigners. Try to use one, and only hints of incomplete documentation will be found. Is the problem patents? No, not really.

[Bunnie] has dubbed the phenomenon “Gongkai”, a type of institutionalized, collaborative, infringementesque knowledge-exchange that occupies an IP equivalent of bartering. Not quite open source, not quite proprietary. Legally, this sharing is only grey-market on paper, but widespread and quasi-accepted in practice – even among the rights holders. [Bunnie] figures it is just the way business is done in the East and it is a way that is encouraging innovation by knocking down barriers to entry. Chinese startups can churn out gimmicky trash almost on whim, using hardware most of us could only dream about for a serious project.

He contrasts this with the West where only the big players like Apple and Google can step up to the plate. Everyone else is forced to use the embarrassingly obsolete hardware we are all familiar with. But [Bunnie] wants to get his foot in the door. “Can we find a way to still get ahead, yet still play nice?” he asks.

Part of his solution is reverse engineering so that hardware can simply be used – something the EFF has helped legally ensure under fair use. The other half is to make it Open Source. His philosophy is rooted in making a stand on things that matter. It is far from a solid legal foundation, but [Bunnie] and his lawyers are gambling that if it heads to a court, the courts will favor his side.

The particular board targeted is the one described above – the MT6260. Even spurred by the shreds of documentation he could gather, his company is a 2-man team and cannot hope to reverse engineer the whole board. Their goal is to approach the low-hanging fruit so that after a year, the MT6260 at least enters the conversation with ATMega. Give up trying to use it as a phone; just try to use like the Spark Core for now.

He is already much of the way there. After telling you what is on board and why we would all want to use it, [Bunnie] shows how far he has gone to reverse engineering and describes his plans for the rest. From establishing an electronic “beachhead” base of operations to further probe the device, to X-rays, photos, diagrams and the beginnings of an OS. If this type of thing interests you at all, the meticulous approach and easy-reading of this tech teardown will surely impress and inspire you. Every step of progress requires a new hack, a new solution, a new ingenious way to pry information out.

We’ve featured some awe-inspiring reverse engineering attempts in the past, but this is something that is still new and relevant. Rather than only exploit his discoveries for himself, [Bunnie] has documented and published everything he has learned. Everyone wins.

Thanks [David] for the tip.

Filed under: Cellphone Hacks, hardware, slider, teardown