I'm trying to build a diagnostic tool...

[ChrisTechMech]

I can't find a tool so I'm trying to build it. Short version... I'm attempting to build a device that will plug into various environmental sensors. It will accept the sensors' readings and send the data via Bluetooth to my android device. An app will translate the data for my records. The Bluetooth chip I found has USB pins. VCC or 5VDC, D+, D-, GND. What type of input does the USB need to recieve? I'm planning on powering the device with a 9V batterythrough a voltage regulator down to 5VDC. Any help would be appreciated.

 

[CocaCola]

http://en.wikipedia.org/wiki/Universal_Serial_Bus

Pull down to signaling for a primer...

 

[ChrisTechMech]

I'm an HVAC tech, no electronics guru for sure. Am I right in assuming that I bring 5VDC to my USB/Bluetooth chip at the VCC pin and ground to the neg side of the battery and connect my two-wire sensor to D+, D-? Then allow my USB2.0/Bluetooth chip to send that signal to my android device? Does that sound accurate? Also, my sensor says it's rated at 2kOHM. Anything special I need to consider there when selecting my voltage reducer or other circuitry?

 

[CocaCola]

Sadly it's not that easy...

If the Bluetooth thing you purchased expects USB standard communications on the D+ and D- lines then the sensors will have to comply with that standard and act as a USB host... Most sensors output an analog or digital voltage, they do not act as a USB host pumping out USB serial communications...

Some more information on what exactly you have might help, but for most hobbyist use Bluetooth dongles us simple serial protocol that is compatible with most microcontrollers they are not USB expecting a USB host... If the Bluetooth module you have wants a USB host you will need to supply it with one, and that is a world of work if you have no grounding in the field...

 

[ChrisTechMech]

Good advice. I haven't bought any parts yet, still in concept/theory mode. So I can buy a generic Bluetooth dongle, plug into a generic micro controller, program the micro controller, and send data via Bluetooth? I'm looking at reading pressures from 0-500 psig (and need at least .5 psig resolution). I think I need at least 12 bit resolution? I think I'm jumping all around here, sorry.

 

[ChrisTechMech]

I was considering using this device and powering it with a battery and voltage reducer. Then just plugging in my USB/Bluetooth device. http://item.mobileweb.ebay.com/viewitem?itemId=321012776386&cmd=VIDESC