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Tracking a car like it were a computer mouse

optical-mouse-sensor-tracks-vehicle-motion

This is [Paul Mandel's] Ground-truth velocity sensor. That’s a fancy name for a device which tracks the movement of a vehicle by actually monitoring the ground its travelling over. This differs from simply measuring wheel rotation (which is how traditional odometers work) in that those systems are an indirect measurement of motion. For us the interesting part is the use of an ADNS-3080 single-chip optical mouse sensor on the left. It’s cheap, accurate, and only needs to be ruggedized before being strapped to the bottom of a car.

[Paul] designed a case that would protect the electronics and allow the sensor to mount on the uneven underbelly of a vehicle. The optical chip needs to be paired with a lens, and he went with one that cost about ten times as much as the sensor. Data is fed from the sensor to the main system controller using the PIC 18F2221. One little nugget that we learned from this project is to poll a register that always returns a default value as a sanity check. If you don’t get the expected value back it signals a communications problem, an important test for hardware going into the vibration-hell that is automotive technology.

12-axis sensor adds auto screen orientation to this older tablet PC

screen-orientation-sensors

[Mal'oo] has one of those laptop computers whose screen swivels to turn it into a tablet. But the thing is a few years old and didn’t come with an orientation sensor that changes the screen between landscape and desktop, but also knows which side is up. His solution was to add a 12-axis sensor via the mini PCI express header.

The hardware comes in two pieces. The first is a mini-PCIe card to USB interface. This is handy if you want to add a Bluetooth dongle permanently to your computer. But he’s got other things in mind for it. After hacking the BIOS (which for some reason limits what you can plug into this slot) he moved onto the second part which is a USB 12-axis sensor. This picture shows the wires before they were soldered to the USB card. [Mal'oo] couldn’t just plug it in because the sensor wouldn’t have been oriented correctly in relation to the computer. The final product is quite response, as shown in the clip after the jump. [Read more...]

Sensor sleeve makes tablet use easier and benefitial for disabled children

tablet-accessiblity-hack

Pinch-zoom is a godsend (and shouldn’t be patent-able) and although we mourn the loss of a physical keyboard on a lot of device we use a tablet nearly as often as we do a full computer. But the touch screen interface is not open to everyone. Those who lack full dexterity of their digits will find the interface frustrating at best or completely unusable at worst. A team of researchers from the Atlanta Pediatric Device Consortium came up with a way to control touch-screen tablets with a sensor array that mounts on your arm.

The project — called Access4Kids — looks not only to make tablet use possible, but to use it as a means of rehabilitation. The iPad seen above is running a custom app designed for use with the sensor sleeve. The interface is explained in the video after the break. Each sensor can serve as an individual button, but the hardware can also process sequential input from all three as a swipe in one direction or the other. If they can get the kids interested in the game it ends up being its own physical therapy coach by encouraging them to practice their upper body motor skills.

[Read more...]

Online radiation monitoring station

geiger-counter-build

This is a Geiger counter which charts its readings on a webpage. [Radu Motisan] put a lot of time into the build and it shows. This thing is packed with features and the hardware choices were the best combinations found through several iterations of development.

In addition to radiation levels the sensor unit takes several other measurements. These include temperature, humidity, luminosity, and barometric pressure. All of the sensor data is monitored and gathered by an ATmega168 which can be charted on a webpage with the help of an ENC28J60 Ethernet chip. The collection and display of this data is detailed at the post linked above.

For those interested in the hardware development, [Radu] published many updates along the way. These are available in his forums posts, as well as his build log. He doesn’t have any videos of his recent work, but way back in May he did publish a clip (found after the break) which shows the testing of different Geiger tubes.

[Read more...]

Conductive filament means printable sensors

The 3D printer world has the creation of plastic trinkets pretty much down pat. The next step, obviously, is the creation of multi-material models, whether they be made of two different colors of plastic, or completely different materials entirely. A few folks from the University of Warwick and GKN Aerospace in Bristol, UK have come up with a way of putting electronic sensors directly into 3D printed objects.

These new sensors rely on a conductive filament custom-made for this study. So far, the researchers have created flex sensors, capacitive buttons, and a ‘smart’ mug that can sense how much water is contained within.

To produce their ‘carbomorph’ filament, the researchers stirred regular old carbon black to a sample of polycaprolactone dissolved in a solvent. After shaking well, the mixture was laid out on a piece of glass for an hour resulting in a thin film that could then be rolled into a 3mm filament. While this is a great way of producing small quantities of carbomorph filament, we’re sure a few Hackaday readers can come up with an easier way of rolling their own conductive filament. Send us a link if you’ve figured out a better way.

Tip ‘o the hat to [Evan] for this one

Hacking BodyBugg fitness sensors to get around subscription fee

This arm cuff is a sensor package which logs data whenever you’re wearing it. It records accelerometer data, skin temperature, and galvanic skin response. That data can then be analyzed to arrive at figures like calories burned. But… The company behind the device seems to have included a way to keep the cash flowing. Once you buy it you can read the data off of the device using a Java program they supply. But you can’t erase the data from the device unless you subscribe to their online service. Once it fills up, it’s useless. [Doug] wasn’t happy with this gotcha, so he reverse engineered the technique used to clear the BodyBugg’s memory.

There had been a few previous attempts at reverse engineering the device but that groundwork didn’t really help [Doug] on his quest. He ended up disassembling the Java classes from the original program. This helped him figure out how to initialize communications. Once there he was happy to find that the device will tell you how to use it. If you issue an invalid command it will respond with a list of all valid commands. Everything you need to get up and running can be found in his github repo.

Adding Node.js based sensors to the Parrot AR drone

[Max Ogden] wanted the option to add sensors to his Parrot AR Drone. This a commercially available quadcopter which runs Linux. This makes it rather easy for him to use Node.js to read the sensors from an Arduino board. The use of the Arduino is merely for easy prototyping. It is only needed to bridge the drone’s serial port with a sensor’s delivery method, so just about any microcontroller could be substituted for it.

There are some hardware considerations to take into account. The manufacturer was nice enough to populate a 0.1″ pitch pin socket on the serial port (if only this kind of invitation to mess with hardware was an industry standard). But the device expects 3.3V levels so pick your hardware accordingly. There is one commenter who tried the project for themselves and found that the drone wouldn’t boot up with the Arduino already connect — he had to boot and then complete connections. Troubles aside this makes adding your own sensor payload very simple and you don’t have to wait until landing to get at the data.

Maybe we’ll have to add some shock voltage data reporting to our shockerDrone.

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