When [Chris Nafis] built an addition onto his historical home he found that a Radon problem, previously mitigated with plenty of concrete, seemed to rear its ugly head yet again. He eventually resigned himself to installing a Radon fan and detector – the latter of which offered no way to store measurement data. He wanted to get a better feel for the short and long-term Radon measurements in his house, in hopes of finding some correlation between temperature, moisture levels, and the total amount of Radon emitted from the ground.
To do this, he disassembled a pair of Radon detectors located in different parts of his house, each of which he wired up to an Arduino. Using his oscilloscope to determine which PCB leads controlled the different LED segments on the displays, he quickly had the Arduinos scraping measurement data from the sensors. [Chris] figured the best way to keep track of his data was to do it online, so he interfaced the microcontrollers with Pachube, where he can easily analyze his historical readings.
An additional goal he set for himself is to trigger the Radon fan only when levels start rising in order to save a little on his electric bill. With his data logging operation in full swing, we think it should be a easy task to accomplish.
The team over at the Louisville Hackerspace LVL1 is not going to be outdone when it comes to collecting environmental data. They put together this Frankenstein of sensor boards that lets you collect a heap of data showing what is going on around it.
At the center-left a small Arduino clone is responsible for collecting the data. Data storage is not talked about on their write-up, but if that’s an ATmega328 chip you should be able to work out an easy way to store data on the 1k of internal EEPROM. If that’s not enough, there is an I2C bus included on the board making it easy to add a compatible EEPROM.
The sensor on the bottom left should look familiar. It’s a DHT11 temperature and humidity sensor we’ve seen popping up in projects lately. But wait, there’s also a TMP102 temperature sensor; but that’s not the end of it. A BMP085 pressure sensor also includes a third temperature sensing option. Want to see when the lights go on in the room? There’s a CdS sensor and a TSL230R Lux sensor for that. An op-amp circuit can measure the sound level in the room via one of the Arduino’s ADC pins. And finally, an RTC board is used for time stamping the data.
Obviously this is overkill, and we’re sure it’s meant as a test platform for various sensors. All of them have been mounted on the protoboard and wired up using the point-to-point soldering method.
The line between serious research and well-executed hacks has been getting pretty blurry lately. The device above could have been designed in your basement but it actually comes from researchers at the University of Washington. They are working on low-power home automation sensors for monitoring things like humidity, temperature, air quality, and light. The key point in their research has been the use of a home’s electrical system for wireless communication. Operating at 27 MHz has proven quite efficient to the point that one of these modules placed within 10-15 feet of an electrical run can communicate with the rest of the home, powered only by a watch battery projected to last ten years.
That’s kind of exciting, it’s a heck of a lot easier to produce and distribute a set of small boards like this than to run communication wiring throughout the house. Now we just need to pair this with the Air Force’s parasitic power work and there’ll be no need for a battery at all.
Our friends over [adafruit] recently released the Sensor Pack 900, a collection of parts for anyone who is interested in using analog sensors with their projects. The pack includes 9 sensors. They range from simple thermistors and hall effect sensors to sharp distance sensors. Also included in the pack are 3 unidentified components that can be used to interface with the analog sensors in the pack. At only $30, the Sensor Pack 900 seems to offer a great set of introductory components for anyone prototyping a new device.
Sharp GP2D12 and 2Y0A02 infrared rangers output a voltage proportionate to the distance of an object from the sensor. The GPD12 senses objects at a distance of 10-80cm, while the 2Y0A02 has twice the range.
We’ve previously looked at the Sharp GP2Y0D02 digital proximity sensor. It only signals the presence of objects, while the GP2D12 and 2Y0A02 measure distance to them. If you’ve got a GP2YoD02, it might still be possible to tap the analog output. We’ll show you how use these sensors below.
Continue reading “Parts: Analog distance sensors (Sharp GP2D12/2Y0A02)”
Yesterday we linked to an OCZ Neural Acutator Interface teardown. Several in the comments wanted to know more about the sensor electrodes. Check out the OpenEEG project and OpenEEG mailing list for information on sensing, amplifying, and recording brain activity (EEG). The OpenEEG project maintains an open source Simple ModularEEG design. Two other open source variants of the ModularEEG are the MonolithEEG and [Joshua Wojnas’] Programmable Chip EEG BCI. All three projects use Atmel microcontrollers, with designs in Cadsoft Eagle.
Brain activity is measured using passive or active electrodes. Passive electrodes require a conductive paste to make proper contact with the skin (examples: 1, 2). Active EEG sensors don’t need conductive goop because they have an amplifier directly on the electrode (examples: 1, 2, 3).
[via anonymous reader, comments]