Building the W800 Antenna

I decided it's time to get rid of the original whip antenna that came with my W800 and build this antenna. Acquiring the parts became a treasure hunt. I picked up the nuts, bolts, washers and crimp lugs at Home Depot then headed over to Radio Shack for the SO-239 parts. Turns out the F to SO-239 Adapter isn't a regularly stocked item around here. I could order it or go to a Shack 30 minutes away and get it. Instead, I left empty handed and headed over to Fry's. There I found the Chassis Mount UHF SO-239 Coax Connector for a mere $1.49 vs. $3.69 at the Shack, but they didn't have the F to SO-239 adapter. They did have a BNC Female to SO-239 adapter and I happened to have a spare BNC Male to F connector at home.



I had still one more stop as I couldn't find the 1/16" brass rod at Home Depot. I stopped by my local Orchard Supply Hardware and found 3 packs of 1/16" x 12" brass rods for $1.79. Good enough.



Finally, I was able to start the project. Instead of a hacksaw to cut the rods, I used diagonal pliers. I also crimped the lugs after I inserted the rods - then I soldered them. Other than that, I followed the directions in the write up. I've got it temporarily hanging in my office but plan to put it in the attic this weekend. The whip antenna is in the attic but it can't see a Hawkeye motion sensor I just put in the backyard. The new antenna, on the other side of the house, can pick it up sometimes, so it should be a lot better in the middle of the attic.

Update: I've hooked it up to the RFID reader via a coax splitter and I have not had any dropouts! The antenna is still sitting in my office.

RFID Battery Mod Follow Up

It's been almost 6 months since I did the battery mod for the RFID receivers. All 3 transmitters are going strong. This is what I was looking for in terms of battery life, especially since the form factor with the battery pack isn't an issue. I did extend the antenna on the receiver some time ago. The range is pretty decent and I'm able to pick up the cars before they reach the driveway.

More Needed Maintenance

We're using the CheaperTronics 8 meter RFID transmitters for vehicle tracking. The problem is they are really sensitive to voltage levels and as the 2032 battery output drops, the transmitters start dropping out. The batteries become useless after several months so today I picked up some AAA battery holders from Radio Shack. I soldered the battery holder wires to the transmitter circuit board loaded it up with a couple batteries and rubber banded it to the case. They work great now. We'll see how long the batteries and reliability last.

Random Stuff

My pair of Nokia 770s arrived this week and I've been playing with them on & off. They appear to have some issue with one of our wireless routers, a Netgear. This appears to be a common problem. It doesn't seem to want to connect to it at all, it keeps trying to connect to our Linksys eventhough it's far away. A few places I've been visiting for more information:
Nokia770.com
Internet Tablet Talk
Maemo.org

The 8M RFID transmitters also arrived and I plugged them in and they worked right away. They're in a much smaller formfactor than the 40M and use only one 3V lithium battery instead of 2. The transmitters in the garaged cars come in strong, but the one in the driveway/street parked car isn't quite working well. I've moved the MSS-100 & RFID receiver closer to the front of the house and it's still a little sketchy. I'm going to have to do a little more tuning. I'd hate to have to put an antenna on the receiver.

Finally, I've been doing more Python scripting. Wrote a few scripts to do screen scraping of certain websites, like Craigslist. I'd put them up, but I don't want people copying them and hammering those sites. There's no benefit to me then :)

HA Server Rebuild...Again

I had to rebuild my HA server due to a failure in my current server. It took a while to get everything configured, but it's finally up and stable. It's a Core 2 Duo e6420 running on an ECS mobo with 2 GB of ram. I put in an Antec EarthWatts high efficiency power supply. Compared to the Athlon XP 2800+ box, this one runs only about 100 watts (vs 145) and is considerably cooler. The exhaust air is only slightly warm compared to the Athlon's, which was hot.

I've been having problems with the RFID transmitters, which appear to be failing. However, when I send them back, the seller says they work fine. I've tried putting the receiver on the PC serial port, on an Edgport serial to USB adapter and on a Lantronix MSS-100 serial to ethernet adapter. I tried new batteries, relocating the receiver, etc. This happened 3 times, so I've returned them in exchange for some 8M units. Hopefully those will work better.

I've since relocated the receiver closer to where the cars are using the MSS-100 so that should compensate for the transmitters being 8M instead of 40M. We'll see when I get them later this week.

In the meantime, I'm also waiting for a couple Nokia 770 internet tablets that I wooted last week.

Make sure those PICs are securely seated!

The PIC in one of my RFID transmitters was not properly seated and as a result it didn't work. It was just slightly unseated on one side, but after removing and replacing the PIC, everything worked fine again.

Haven't had much time to post these days. I've been busy finishing up a chip at work and beta testing starCOMUltra...

RFID update

The minor reception problem I was having is gone. I just moved the receiver slightly and all 3 transmitters are coming in perfectly. It's just sitting on my office desk - no need for a fancy antenna. Everything's great except I read that the battery life on these things is about 2-3 months! I'll find out soon enough and maybe I'll have to figure out a new way to power these things...

RFID tracking going well

It took about 15 minutes to pop the batteries in the transmitters, throw them in the 3 cars and write up some code in starCOMUltra to do the vehicle tracking. They send out a beacon about every 2.5 seconds which the receiver picks up and sends a 4 character string to a serial port that sCU is watching. This code tracks the arrival of cars:

function AUXPorts::AUX2_LineIn(Line) {
    var TempLine;
    if (Line.substr(0,4)=="2xyz") {
      if (CarsCheck(Car1)==0) {
        TempLine ="# AUX 2:\tCar 1 Home";
        LogDevice(TempLine);
        CarsChange(Car1,1);
        Speech.speak("R is home");
      } else {
        CarsInTime[0]=TimeSecs();
      }
    }
}

To track the departure of cars, my sCU script checks every 2 minutes if a car hasn't been heard from in a little while:

function ScriptTimers::Trigger(Index) {
    var secs;
    Site.LogDevice("# sCU Timer: " + ScriptTimers.Item(Index).Name + 
    " ("+ Index + ") expired");
    
    switch(Index) {
...
     case 1: // 2 minute
     ScriptTimers.Item("TwoMinuteTimer").Continuous = -1;
     ScriptTimers.Item("TwoMinuteTimer").Time = 120;
     secs=TimeSecs();
     if ((secs-CarsInTime[0])>90 && CarsCheck(Car1)==1) {
        CarsChange(Car1,0);
        LogDevice("# Cars:\tCar 1 Away");
     }
     break;
...

I haven't done any fine tuning of the placement of the receiver or of the transmitters in the cars. I have noticed that the car parked outside has occasional dropouts so I'll definitely be looking at re-positioning and possibly adding an antenna to the receiver. Overall, it was a very smooth install and I got right back to sCU beta testing.

RFID kit coming

I ordered an RFID receiver and 3 transmitters from http://wingsnwakes.com and I think I'll finally get them today. They've been downstairs in the mailroom of the company below us since Thursday morning. For whatever reason, we don't get USPS delivery directly since we occupy the 2nd floor of a building. It has to go through the downstairs company and they have to sort it out for us, but the guy who sorts it has been sick for a week. I guess nobody at my company gets anything important via mail because nobody else complained about not getting mail all week.

In any case, the transmitters will be put in our cars to replace the DS10A's I've been using for vehicle tracking. This will be much more accurate and a good test run to see if I'll "need" to add more transmitters to the system.

On a side note, starCOMUltra testing has gone full speed ahead. I've shut off starCOM and switched over completely to Ultra. I've spent the past week converting over piles of scripts and ASP pages to use Ultra and it's been very stable. It's been a good exercise as it's giving me a reason to clean up and streamline a bunch of scripts. I've been making good progress but I think the RFID stuff will sidetrack me this week.