New Project: Wireless display

Hi!
I am currently working on a new hobby-ist project:

  • a Wireless display for a (normally) wired device.

The wired device in question is a temperature sensor, you currently connect it to your computer Via a uUSB-to-USB connection and open up its Java software (which looks like it was based on LabView). and you can read temperature of the probes you connect to the device.

What I want to do is some sort of dongle that connects so the back of this device (via its micro-USB port) and acts as a pass through as well as a wireless antenna for Android devices using Bluetooth (maybe iOS too, but I know thats another ordeal I dont really want to get into right now).

My question is:

  • Is this easily done? (I have basic programming, soldering and design skills)
  • Is there maybe something like this already out there?

I currently own a Teensy development board which I would like to use as the base for my dongle,
this will additionally house a battery (since the device itself runs off power supplied off USB, which will not always be there).

Quick_questions:

  • Is this easily done?

I suspect a lot easier than you think

Assuming that your Teensy has at least one serial port I don't think you need any USB dongle or whatever. Just connect a $7 bluetooth module to the serial port and you are off and running. I draw your attention to Bluetooth Graphics Terminal, a really good Android app that allows you to graph up to three temperature sensors simultaneously.

You might find the following background notes useful

http://homepages.ihug.com.au/~npyner/Arduino/GUIDE_2BT.pdf
http://homepages.ihug.com.au/~npyner/Arduino/BT_2_WAY.ino

You can already buy wireless temperature and other sensors intended for home weather stations very cheaply. Most transmit on the 433 MHz or other ISM bands, and the transmissions can be received and decoded quite easily with $2 receivers and an Arduino. There are a number of posts on the Arduino forum describing such projects.

Hmm thanks for those articles, they do seem helpful and its making me think its way simpler than I thought it was.

After analyzing the board of the temperature device I found it has a serial port with TX/RX pins on it.

Is it possible to just plug a bluetooth directly to these things and have my signal going?
Here's the catch tho:

  • If i plug this device into PuttY I dont get any signal unless I send some commands first (so its not like its transmitting all the time, it needs to be sent the command in order to start transmitting).

So, my hypothesis is that I need the arduino to send the commands to start transmitting and then just let it transmit via bluetooth.

I am not sure if this is needed or if I am just adding an Arduino for no reason and maybe its possible to just get the bluetooth device connected direclty to the serial of this thing and send the commands via the Java software when opened in an android environment?

Quick_questions:
After analyzing the board of the temperature device I found it has a serial port with TX/RX pins on it.

Is it possible to just plug a bluetooth directly to these things and have my signal going?

Very likely, and certainly worth a try

Here's the catch tho:

  • If i plug this device into PuttY I dont get any signal unless I send some commands first (so its not like its transmitting all the time, it needs to be sent the command in order to start transmitting).

This may be for saving power. The data sheet may have something to say on this

or if I am just adding an Arduino for no reason

Also very likely but it depends on how you need to use things. I think bluetooth is typically for casual short-range, short-term use. You may want to use Arduino for more constant data recording to SD, or send alerts over SMS etc.

bluetooth device connected directly to the serial of this thing and send the commands via the Java software when opened in an android environment?

I have no idea of what java software in an Android environment might be, but it sounds meaningless and I bet you don't need it either. You should be able to send the same command from the Android terminal programme as that which you have already used with Putty.

thank you, I will try that. I am getting the bluetooth module this week, I'll report afterwards!