Tuesday, March 17, 2009

OBDII USB Connector

Can the hardware be sold for less than $50?

Manufacture the hardware and firmware for a USB dongle that will connect a car OBDII port to a laptop (netbook, iPhone, etc.). Publish the API so anyone can make software for any computing platform.

Long cord so whatever display is connected can be easily seen. Optional wifi or bluetooth wireless networking powered by cigarette lighter.

Create a simple PC application to demonstrate the API. Sell the hardware and let others create value-added software.

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http://www.obdii.com/
ATReader-U Hardware and Software Kit with USB Port $129.95

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http://www.obdii.com/forums/ubbthreads.php?ubb=showflat&Number=1228&page=1#Post1228

www.elmelectronics.com sell an 8 pin DIP that can convert the GM or FORD OBDII protocol straight to RS232 that your laptop can read. the chip needs a few external components to work (nothing fancy, a few transistors, resistors etc...) and costs under ten bucks ( $11 canadian).
I'm pretty new to this BB, but I've never seen any such solution discussed here or anywhere else on the web. the tech note they have for the chip (i saw two versions, ford and GM) even shows how to read and reset the trouble codes with nothing but their chip and a laptop running hyperterminal.



The chip at www.elmelectronics.com is simply a Microchip 12C5xx with a simple program to convert RS232 to VPW etc. Motorola has some good chips at http://e-www.motorola.com/webapp/sps/prod_cat/sel_guide.jsp?catId=M98445 or you can goto www.mot-sps.com and search for 9141. The chips are MC32199, MC33290 and MC33390. These chips convert K-line ISO9141 into RS232 or J1850 (VPW) into RS232. Has anybody used these chips and had any success?

Also there is a good article in CircuitCellar from May/June 2000 which describes a home-made interface in some detail.

Like everyone else, I don't think it would be too hard to make a OBD-2 to RS232 interface and then send some interrogation data or simply download a free demo program (from www.obd-2.com?).



Just found a good website with schematics and layout for OBDII to RS232 converter:
http://www.planetfall.com/~jeff/obdii/



Check out this site: http://www.scantool.net, they've got a ready-made interface that uses Elm Electronics' chips.

...

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http://www.scantool.net/elmscan-5-usb.html
ElmScan 5 USB
$139.95
The compact and durable ElmScan 5 USB scan tool supports all OBD-II protocols, features automatic protocol detection, and ships with a number of compatible diagnostic programs.

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200905:
Homebrew kits:

http://www.nerdkits.com/videos/obdii/
http://hackaday.com/2009/05/12/obd-ii-automotive-data-logging/

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200906
Targeted toward large trucks.
PN 125032 USB-Link
PC-to-vehicle interface compatible with multiple software applications, minimizing your investment in multiple brand-specific diagnostic interfaces.

$715 Pro-Link 125032 Nexiq USB Link

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201011
OBDII broadcast via Wifi to smartphone.
$149.99
http://www.thinkgeek.com/gadgets/car/dcf4/

Friday, March 13, 2009

Air De-Stratification with Air Filtering

Most buildings suffer from air stratification, in which air near the ceiling and upper floors is warmer than air near the floor and lower floors. This can be mitigated by constantly running the furnace/air conditioning fan.

For new construction and for motivated remodels, provide a product that contains one (maybe two fans inline depending on length of duct), ductwork, two endcaps, filter and UV. During construction, run a duct from the ceiling to the floor (or upper level to lower level). The fan would run constantly to slowly pull air "down", filter the air, and clean air with UV. The fan + filter enclosure + UV with a couple end-caps to expose in drywall could be sold as a kit. The ductwork and additional filters could be bought at a hardware store. A subscription package of montly filter change and yearly UV light change could be sold.

Less air stratification creates a more uniform atmosphere with may result in less furnace/AC cycling which will save money. The additional air filtering and UV germ killing will create a healthier breathing environment.

The ductwork should be narrow enough to pass in drywall cavity or plumbing run, and the main unit should be accessible for homeowner filter maintenance.
A second inline fan may be needed for long runs of ductwork, or for increased air volume.

Add-on module for monitoring of temperature / humidity / CO2 with wifi communication.

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Cheaper standalone air purifiers (like sharperimage products) are about $120.
Cheap HEPA are $230 Blueair 210B HEPASilent™ Air Purifier with Bonus Particle Filter with price quickly going over $440 Blueair HEPASilent™ 510B Air Purifier with Bonus Filter.
HEPA replacement filters retail for around $100.