Hello World.


 With a little bit of soldering and some code tweaking I was able to drive my multi meter. A good first step and terribly exciting, but I would have to wait to move much further. I was still searching for meters on ebay, and by then I had found Physical Computing and Making Things Talk. So many possible projects... so little time.



After a little (ok.. *a lot*) of searching I found four matching DC volt meters. I actually thought that I had found five; but it turns out that in my haste and excitement the last was AC and would do me no good. As you can see I was able to modify the original code to drive four meters. I have a new found understanding and respect for programming within an environment that provides minimal debugging facilities and limited string manipulation (this was a departure from the vb and ksh scripting environments that I work in daily.)

With the code and base concept working I knew that it would not be allowed in my living room without a proper case so I broke out SketchUp and quickly created this design.





On a trip to the local hard wood lumber store I found a beautiful piece of Walnut. After a few hours work in the wood shop I was able to build the case. (quickly raising the wife acceptance factor)




Knowing that this will not be my last project I ordered another arduino and x-port. I decided to go with the Lilypad and Xport Direct Embedded Device Gateway for size, cost and voltage reasons.



I was able to transfer the wiring layout from the breadboard to a RadioShack prototype board with a little time and frustration. Perhaps next time I will look into printing/etching my own circuit board. To supply power I built a pair of POE adapters. It was all mounted inside with some adhesive, double sided sticky tape and a few zip ties. 


And finally its mounted prominently in the living room. Someday when we move into a more permanent home I will fish the cables thru the wall. In the end (as you can see if you have reviewed the code) I decided to display the Hours, Minutes, Local Tempature, and Local Humidity.

After a few days in the living room I have made a few changes...
First: Two of the meters have a scale of 0-3 and two from 0-1. My wife suggested that the 0-1 scales be used for Tempature and Humitidy (0 to 100) and that the 0-3 scales be used for Hours and Minutes (12 and 60 are easily divisable by 3.) This is the opposite of the way that I had them origionally.

Second: I have found that I cannot drive the system over a long distance reliably. In the picture on the left the cable that supplies data and power is over ~20'. I have moved it to a temporary location on a ~6' cable and everything is currently stable. I am going to have to investigate the quality of the long cable, or the posibility of a larger power supply.

 --Update: I was able to solve the reliability issues with a 'watchdog' timer function. Its fairly simple in that it watches to make sure that a cycle has completed within the last 60 seconds. In the event that a cycle has not completed within 60 seconds all of the variables are cleared and the cycle restarted.