Fixing Ghost Touch In The OnePlus One

November 24, 2014 by Brian Benchoff 24 Comments

The OnePlus One is the flagship phone killer for 2014, available only by invite, and thus extremely cool. So far it’s a limited production run and there will, of course, be problems with the first few thousand units. When [vantt1] got his One, he noticed a few issues with the touch screen. Some touches wouldn’t be registered, typing was unpredictable, and generally, the touchscreen was unusable. [vantt] had seen this before, though, so with a complete teardown and a quick fix he was able to turn this phone into something great.

[vantt] realized the symptoms of a crappy touchscreen were extremely similar to an iPad mini that had recently had its digitizer replace. From the Foxconn plant, the digitizer in the iPad mini is well insulated from the aluminium enclosure. When the screen and digitizer are replaced, the cable connecting it to the rest of the iPad can come in contact with the case. This leads to the same symptoms – missed touches, and unpredictable typing.

Figuring the same cure will fix the same symptoms, [vantt] tore apart his OnePlus One and carefully taped off the digitizer flex cable. Reassembling the phone, everything worked beautifully, and without any extra screws in the reassembly process. You can’t do better than that.

Custom Filaments With A Filastruder

November 24, 2014 by Brian Benchoff 12 Comments

A while ago, when 3D printing was the new hotness, a few people looked around and said, ‘our printers are open source, why can’t we just build the machines that make our 3D printing filament?’ There was a $40,000 prize for the first person to build an open source filament extruder, resulting in a few filament fabrication machines being released into the wild. [Rupin] over in the Mumbi hackerspace has one of these filament extruders – a Filastruder – and decided to take a look at what it could do.

The experimentations began with a few kilograms of ABS pellets he found at the market, with bags of red, blue, green, and white masterbatch pellets showing up at the Hackerspace. Experimenting with these pellets, [Rupin] was able to create some very nice looking filament that printed well and changed color over the course of a print.

There were a limitations of the process, though: the filastruder has a long melt zone, so colors will invariably mix. If you’re thinking about doing a red to blue transition with filament created on a Filastruder, you’ll end up with a filament with a little bit of red, a little bit of blue, and a lot of a weird purple color. The time to create this filament is also incredibly long; over the course of two days, [Rupin] was able to make about half a kilo of filament.

Still, the results look fantastic, and now that [Rupin] has a source for masterbatch and ABS pellets, he’s able to have a steady supply of custom color filament at the hackerspace.

Cairo Hackerspace Gets A $14 Projector

November 23, 2014 by Brian Benchoff 21 Comments

The Cairo hackerspace needed a projector for a few presentations during their Internet of Things build night, and of course Friday movie night. They couldn’t afford a real projector, but these are hackers. Of course they’ll be able to come up with something. They did. They found an old slide projector made in West Germany and turned it into something capable of displaying video.

The projector in question was a DIA projector that was at least forty years old. They found it during a trip to the Egyptian second-hand market. Other than the projector, the only other required parts were a 2.5″ TFT display from Adafruit and a Nokia smartphone.

All LCDs are actually transparent, and if you’ve ever had to deal with a display with a broken backlight, you’ll quickly realize that any backlight will work, like the one found in a slide projector. By carefully removing the back cover of the display, the folks at the Cairo hackerspace were able to get a small NTSC display that would easily fit inside their projector.

After that, it was simply a matter of putting the LCD inside the display, getting the focus right, and mounting everything securely. The presentations and movie night were saved, all from a scrap heap challenge.

A Simple Runner’s GPS Logger

November 23, 2014 by Brian Benchoff 13 Comments

[Daniel] received a grant from the University of Minnesota’s ECE Envision Fund and was thus responsible for creating something. He built a runner’s GPS logger, complete with a screen that will show a runner the current distance travelled, the time taken to travel that distance, and nothing else. No start/stop, no pause, nothing. Think of it as a stripped-down GPS logger, a perfect example of a minimum viable product, and a great introduction to getting maps onto a screen with an ARM micro.

The build consists of an LPC1178 ARM Cortex M3 microcontroller, a display, GPS unit, and a battery with not much else stuffed into the CNC milled case. The maps come from OpenStreetMap and are stored on a microSD card. Most of the files are available on GitHub, and the files for the case design will be uploaded shortly.

The CNC machine [Daniel] used to create the enclosure is a work of art unto itself. We featured it last year, and it’s good enough to do PCBs with 10 mil traces. Excellent work, although with that ability, we’re wondering why the PCB for the Runner’s GPS is OSH Park purple.

Hackaday Links: November 23, 2014

November 23, 2014 by Brian Benchoff 3 Comments

The 2015 Midwest RepRap Festival, a.k.a. the MRRF (pronounced murf) was just announced a few hours ago. It will be held in beautiful Goshen, Indiana. Yes, that’s in the middle of nowhere and you’ll learn to dodge Amish buggies when driving around Goshen, but surprisingly there were 1000 people when we attended last year. We’ll be there again.

A few activists in St. Petersburg flushed GPS trackers down the toilet. These trackers were equipped with radios that would send out their position, and surprise, surprise, they ended up in the ocean.

[Stacy] has been tinkering around with Unity2D and decided to make a DDR-style game. She needed a DDR mat, and force sensitive resistors are expensive. What did she end up using? Velostat, conductive thread, and alligator clips.

You know the Espruino, the little microcontroller board that’s basically JavaScript on a USB stick? Yeah, that’s cool. Now you can do remote access through a telnet server letting you write and debug code over the net.

The Open Source RC is a beautiful RC transmitter with buttons and switches everywhere, a real display, and force feedback sticks. It was a Hackaday Prize entry, and has had a few crowdfunding campaigns. Now its hit Indiegogo again.

Speaking of crowdfunding campaigns, The Mooltipass, the designed-on-Hackaday offline password keeper, only has a little less than two weeks until its crowdfunding campaign ends. [Mathieu] and the rest of the team are about two-thirds there, with a little more than half of the campaign already over.

[Sprite_TM]’s Keyboard Plays Snake

November 23, 2014 by Brian Benchoff 22 Comments

Hackaday Prize judge, hacker extraordinaire, and generally awesome dude [Sprite_TM] spends a lot of time at his computer, and that means a lot of time typing on his keyboard. He recently picked up a board with the latest fad in the world of keyboards, a board with individually addressable LEDs. He took this board to work and a colleague jokingly said, ‘You’ve had this keyboard for 24 hours now, and it has a bunch of LEDs and some arrow keys. I’m disappointed you haven’t got Snake running on it yet.” Thus began the quest to put the one game found on all Nokia phones on a keyboard.

The keyboard in question is a Coolermaster Quickfire Rapid-I, a board that’s marketed as having an ARM Cortex CPU. Pulling apart the board, [Sprite] found a bunch of MX Browns, some LEDs, and a 72MHz ARM Cortex-M3 with 127k of Flash and 32k of RAM. That’s an incredible amount of processing power for a keyboard, and after finding the SWD port, [Sprite] attempted to dump the Flash. The security bit was set. There was another way, however.

Coolermaster is actively working on the firmware, killing bugs, adding lighting modes, and putting all these updates on their website. The firmware updater is distributed as an executable with US and EU versions; the EU version has another key. Figuring the only difference between these versions would be the firmware itself, [Sprite] got his hands on both versions, did a binary diff, and found only one 16k block of data at the end of the file was different. There’s the firmware. It was XOR encrypted, but that’s obvious if you know what to look for.

The firmware wasn’t complete, though; there were jumps to places outside the code [Sprite] had and a large block looked corrupted. There’s another thing you can do with an executable file: run it. With USBPcap running in the background while executing the firmware updater, [Sprite] could read exactly what was happening when the keyboard was updating. With a small executable that gets around the weirdness of the updater, [Sprite] had a backup copy of the keyboard’s firmware. Even if he bricked the keyboard, he could always bring it back to a stock state. It was time to program Snake.

The first part of writing new firmware was finding a place that had some Flash and RAM to store the new code. This wasn’t hard; there was 64k of Flash free and 28K of unused RAM. The calls to the Snake routine were modified from the variables the original firmware had. If, for example, the original keyboard had a call to change the PWM, [Sprite] could change that to the Snake routine.

Snake is fun, but with a huge, powerful ARM in a device that people will just plug into their keyboard, there’s a lot more you can do with a hacked keyboard. Keyloggers and a BadUSB are extremely possible, especially with firmware that can be updated from a computer. To counter that, [Sprite] added the requirement for a physical condition in order to enter Flash mode. Now, the firmware will only update for about 10 seconds after pressing the fn+f key combination.

There’s more to playing Snake on a keyboard; Sprite has also written a new lighting mode, a fluid simulation thingy that will surely annoy anyone who can’t touch type. You can see the videos of that below.

Continue reading “[Sprite_TM]’s Keyboard Plays Snake” →

Down The Rabbit Hole Of STM32 Clock Options

November 23, 2014 by Mike Szczys 14 Comments

Once you venture beyond the tame, comfortable walls of the 8-bit microcontroller world it can feel like you’re stuck in the jungle with a lot of unknown and oft scary hazards jut waiting to pounce. But the truth is that your horizons have expanded exponentially with the acceptable trade-off of increased complexity. That’s a pretty nice problem to have; the limitation becomes how much can you learn.

Here’s a great chance to expand your knowledge of the STM32 by learning more about the system clock options available. We’ve been working with STM32 chips for a few years now and still managed to find some interesting tidbits — like the fact that the High Speed External clock source accepts not just square waves but sine and triangle waves as well, and an interesting ‘gotcha’ about avoiding accidental overclocking. [Shawon M. Shahryiar] even covers one of our favorite subjects: watchdog timers (of which there are two different varieties on this chip). Even if this is not your go-to 32-bit chip family, most chips have similar clock source features so this reading will help give you a foothold when reading other datasheets.

There is a clock diagram at the top of that post which is small enough to be unreadable. You can get a better look at the diagram on page 12 of this datasheet. Oh, and just to save you the hassle of commenting on it, the chip shown above is not an f103… but it just happened to be sitting on our desk when we started writing.