Author: Jenny List

3312 Articles

Hackaday Prize Entry: Raspberry Pi Thermal Imaging

September 25, 2016 by 12 Comments

High up on the list of desirable technologies that are edging into the realm of the affordable for the experimenter is the thermal camera. Once the exclusive preserve of those with huge budgets, over the last few years we’ve seen the emergence of cameras that are more affordable, and most recently a selection of thermal camera modules that are definitely within the experimenter’s range. They may not yet have high resolution, but they are a huge improvement on nothing, and they are starting to appear in projects featured on sites like this one.

One such device is the Melexis MLX90621, a 16×4 pixel thermal sensor array in a TO39 can with an I2C interface. It’s hardly an impulse purchase in single quantities and nor is it necessarily the cheapest module available, but its price is low enough for [Alpha Charlie] to experiment with interfacing it to a Raspberry Pi for adding a thermal camera overlay to the pictures from its visible light camera.

The wiring for the module is simplicity itself, and he’s created a couple of pieces of software for it that are available on his GitHub repository. mlxd is a driver daemon for the module, and mixview.py is a Python graphical overlay script that places the thermal array output over the camera output. A run-through of the device and its results can be seen in the video below the break.

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Rubidium Disciplined Real Time Clock

September 25, 2016 by 14 Comments

[Cameron Meredith] starts the Hackaday.io page for one of his projects by quoting a Hackaday write-up: “A timepiece is rather a rite of passage in the world of hardware hacking“. We stand by that assertion, but we’d say most of the clocks we feature aren’t as capable as his project. He’s made a real-time-clock module controlled by a rubidium frequency standard, and since it also includes a GPS clock he can track local time dilation effects by comparing the two.

Surplus rubidium standards are readily available, but each description of one seems to feature a lot of old-fashioned hardware hacking simply to get it working. This one is no exception, an unusual connector had to be replaced and an extra power supply module attached. Once those modifications had been made and a suitable heatsink had been attached, he was able to bring the rubidium standard, an RTC module, and GPS module together with an ATMega32U4 miniature Arduino-compatible board and an LCD display. The firmware is functional, but he admits it is not finished.

All the project’s files can be found on the Hackaday.io page linked above. Future plans include also monitoring the NIST WWVB radio time signal from Fort Collins, Colorado, for an extra time dilation comparison.

We’ve featured innumerable clocks over the years here at Hackaday, but among them have been a few based upon atomic standards. More than one has been used as a lab reference standard, but most similar to this build is [Max Carters] experiments to check the accuracy of an atomic standard, also using the WWVB transmissions.

Hackaday Prize Entry: Theia IoT Light-switch

September 24, 2016 by 17 Comments

There are it seems no wireless-enabled light switches available in the standard form factor of a UK light switch. At least, that was the experience of [loldavid6], when he decided he needed one. Also, none of the switches he could find were open-source, or easy to integrate with. So he set out to design his own, and the Theia IoT light switch is the result.

In adapting a standard light switch, he was anxious that his device would not depend on the position of the switch for its operation. Therefore he had to ensure that the switch became merely an input to whichever board he designed, rather than controlling the mains power. He settled upon the ESP8266 wireless-enabled microcontroller as the brains of the unit, with a relay doing the mains switching. He first considered using an LNK304 off-line switching PSU chip to derive his low voltages, but later moved to an off-the-shelf switch-mode board.

So far two prototype designs have been completed, one for each power supply option. Boards have been ordered, and he’s now in the interminable waiting period for international postage. All the KiCad and other files are available for download o the project’s hackaday.io page, so you can have a look for yourselves if you are so inclined.

You might ask why another IoT light switch might be needed. But even though they are now available and inexpensive, there is still a gap for a board that is open, and more importantly does not rely on someone else’s cloud backend. Plus, of course, this board can be used for more than lighting.

Light bulb image: Осадчая Екатерина (Own work) [CC BY-SA 4.0], via Wikimedia Commons.

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Hackaday Prize Entry: Catch The IMSI Catchers

September 23, 2016 by 16 Comments

An IMSI catcher is an illicit mobile phone base station designed to intercept the traffic from nearby mobile phones by persuading them to connect to it rather than the real phone company  tower. The IMSI in the name stands for International Mobile Subscriber Identity, a unique global identifier that all mobile phones have. IMSI catchers are typically used by government agencies to detect and track people at particular locations, and are thus the subject of some controversy.

As is so often the case when a  piece of surveillance technology is used in a controversial manner there is a counter-effort against it. The IMSI catchers have spawned the subject of this post, an IMSI catcher detector app for Android. It’s a work-in-progress at the moment with code posted in its GitHub repository, but it is still an interesting look into this rather shadowy world.

How them you might ask, does this app hope to detect the fake base stations? In the first case, it will check the identity of the station it is connected to against a database of known cell towers. Then it will try to identify any unusual behaviour from the base station by analysing its traffic and signal strength. Finally it will endeavour to spot anomalies in the implementation of the cell phone protocols that might differentiate the fake from the real tower.

They have made some progress but stress that the app is in alpha stage at the moment, and needs a lot more work. They’re thus inviting Android developers to join the project. Still, working on projects is what the Hackaday Prize is all about.

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Hackaday Prize Entry: Dodo 6502 Game System

September 22, 2016 by 13 Comments

If you are a gamer of A Certain Age, it’s probable that you retain a soft spot for 8-bit computers and consoles of your youth. For a time when addictive gameplay came through the most minimal of graphics, and when gaming audio was the harshest of square waves rather than immersive soundscapes.

Does the previous paragraph sound familiar? Then we may just have the device for you. The Dodo is a handheld console that harks back to that era with a 6502 processor and a 128×64 pixel OLED screen. Games are loaded from plug-in EEPROM cartridges, and sounds are suitably period-digital square wave tones. It’s the brainchild of [Peter Noyes], and he says he will consider it complete when it sports a game fun enough to entertain his 4-year-old.

The prototype Dodo is a handheld form-factor made from two stacked PCBs. The upper one has the display and buttons while the lower has the classic 6502 and associated chipset in through-hole DIP format. A Game Boy Micro it ain’t, but miniaturization is not the name of the game with these consoles. Best of all though, all the console’s resources are available in a GitHub repository, so you can all have a play too.

The 6502 has featured in a huge number of projects here on Hackaday over the years. Now it’s turned up in the Hackaday Prize.

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Hackaday Prize Entry: LipSync, Smartphone Access For Quadriplegic People

September 21, 2016 by 2 Comments

For most of us, our touch-screen smartphones have become an indispensable accessory. Without thinking we tap and swipe our way through our digital existence, the promise of ubiquitous truly portable computing has finally been delivered.

Smartphones present a problem though to some people with physical impairments. A touchscreen requires manual dexterity on a scale we able-bodied people take for granted, but remains a useless glass slab to someone unable to use their arms.

LipSync is a project that aims to address the problem of smartphone usage for one such group, quadriplegic people. It’s a mouth-operated joystick for the phone’s on-screen cursor, with sip-and-puff vacuum control for simulating actions such as screen taps and the back button.

To the smartphone itself, the device appears as a standard Bluetooth pointing device, while at its business end the joystick and pressure sensor both interface to a Bluetooth module through an Arduino Micro. The EAGLE board and schematic files are available on the project’s hackaday.io page linked above, and there is a GitHub repository for the code.

Technology is such a part of our lives these days, and it’s great to see projects like this bridge the usability gaps for everyone.  Needless to say, it’s a perfect candidate for the Assistive Technology round of the Hackaday Prize.

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Panel Meter-To-Bluetooth Hack Hijacks The Display Segments

September 21, 2016 by 23 Comments

There are a proliferation of cheap digital meter modules available online for pocket money prices. Current, voltage, frequency, or combinations thereof can all be yours for just a few dollars and a wait for shipping. Unfortunately though these meters are all self-contained units. They do not have a serial port or other interface through which you can log their readings.

This failing was not an obstacle for [Scott Harden], though. He simply added a Bluetooth interface to his combined voltage and current meter module by using an ATmega328 microcontroller to capture the signals sent to the module’s display LEDs and interpret them into readings for his Bluetooth module. He details the process of reverse engineering the meter, and his build. The result is an intriguing mess of wires with a DIP ATmega hanging on their ends. But it performs the task requested of it admirably and when mounted in a project box you would not know what lurks within.

He has made his code for the project available in his GitHub repository, we can see that this could be a valuable technique for use with other similar displays. In the video below the break he gives us a full run-down, as if his comprehensive write-up was not enough.

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