05 December 2008

Xbee Chat

OohRah! I now have two Xbees chatting. I hadn't messed with the Xbees for a few weeks because work was crazy and the Holidays, etc. After a few days of vacation, I dusted off the junk and tried to remember where I was.

One Xbee is in an AdaFruit Adapter connected to an Arduino Duemilanove and the other Xbee is in an Xbee Explorer USB.

The Arduino is wired to the Xbee Adapter Kit with only 4 wires. I used wire and connectors from the Wide Screen Salvage project.
  • Arduino Gnd -> Adapter Ground
  • Arduino +5V -> Adapter +5V
  • Arduino Tx -> Adapter Rx
  • Arduino Rx -> Adapter Tx
Note that the Tx->Rx and Rx->Tx. Since the Arduino and Adapter are talking to each other serially, this makes sense. But for the first few attempts, I had Rx-> Rx, Tx->Tx and of course it didn't work.

Digi's X-CTU was used to upgrade firmware. I originally had Coordinator firmware on the Explorer board but communications seemed spotty. Once I put ZNET 2.5 Router/End Device AT firmware on both and configured them like I wrote last month, things started coming together.

The Arduino is running a real simple sketch - it simply writes "Testing" to the Xbee which gets transmitted and then received by the Xbee connected to my PC. I used the X-CTU terminal tab to see the incoming message's. Kinda basic but I needed something to save my sanity.

Here's the next plan. Upgrade firmware on the PC Xbee to API (ZNET 2.5 Router/End Device API) and then use xbee-api - A Java API for Digi XBee/XBee-Pro OEM RF Modules and see if I can start programmatically working with these things.

01 December 2008

Wide Screen HDTV Surgery

Our Sony 46" Rear Projection HDTV had a good life. We bought her new in 2003 and had only minor problems. A few months back, she suffered convergence issues that I just didn't want to pay to have fixed. It was a good excuse to look for an LCD wide screen. So the old Sony was banished to the garage to make room for the new Sony Bravia.

With the convergence problems, I couldn't sell the TV except for parts so what to do with it? Crack it open and see what can be salvaged, of course!

After carefully removing 753 (or so) screws, the rear panel, speaker grille, front panel (beznet) and mirror cover pop right off. The first interesting thing I found was 4 sensors around the perimeter of the beznet. These are pointing in, away from the front. It took me a second to realize the coolness of this design. Your average couch potato points the remote at the screen. The IR goes thru the screen, bounces off the mirror, and gets picked up by one or more of the perimeter "bounce-back" sensors. This, in effect, makes a 46" IR sensor. Very cool.

As I stared at all the various boards and wire harnesses, I figured a Service Manual might come in handy. After much Googling, I located a manual at:
forum.electromaniacs.com - Downloads - Service Manuals - Sony - SONY RA6 CHASSIS KP46WT500 PROJECT

I posted a thread on Make Magazine's blog to see if anyone had ideas on tasty parts to take and/or suggestions to do with this thing. The best response was actually what I expected. Maybe some good wires, connectors, and capacitors. But basically boring.

Other than the IR sensors I mentioned above, I haven't seen any cool things. The bulbs were disappointing as they are actually CRTs which don't appear to have any obvious secondary use. The speakers are a keeper as well as the magnifying screen. When the weather cooperates, I'll go back to the garage and see what else has promise.