WT4M's OCTOPUS CONSOLE
Big thanks out to Scott (N1VG) and Jason (KE4NYV) for letting my XYL know where I am at all times. (Yikes!) Scott for designing the OpenTracker and Jason for hooking me at the CARS SpringFest!
Since I already had a radio box built into my truck, I wanted to have console type controls for the OT1x. This outlines what I did to accomplish that end (more or less successfully).
First I assembled the OT1x, all in one sitting. I convinced myself that it would be best to test it the following day, after getting some much needed sleep. But in the end my curiosity won and I foolishly pressed testing in the same evening. Wouldn’t you know it, I hooked up power with the polarity reversed! The 5 volt rectifier was not very happy with this situation and surrendered after a few milliseconds I suppose.
Fortunately the rest of OT1x is a tough cookie and persevered! After a quick trip to Rat Shack and a little more solder it was back up and running like a champ.
After some steep learning curves with APRS SSIDs, I am now transmitting as WT4M-14. Not that I am a purist, but I believe Bob Bruninga (WB4APR) should have the final word. I started with just WT4M and then WT4M-9 (as Bob listed 14 as “truckers” somewhere or another). I had assumed this meant of the more than two axle kind. The whole SSID thing is kind of murky, so probably anything goes, but I think I will stick with 14 for my Silverado…
By the by, I found that findu.com left a lot to be desired as far as tracking goes. After some extensive searching I found this awesome site in Helsinki! If you haven't been there yet, once you use it, I'd doubt if you would ever use any of the others...
In order to accomplish my “console” I needed to modify three OT1x lines on X1. I wanted to keep the box as close to original design as possible, but definitely wanted to have a console LED!
I am not certain if I had to modify Pin 8 to JP3 or not, it may have suited my purpose as it was, but I didn’t want to chance it.
OT1x X1 Pin 2 (Change to LED OUTPUT):
I didn’t need the “COR/SQUELCH INPUT” for the HTX-212, so I cut the trace that leads to the junction of the RX variable resistor and C3. I then jumpered from X1 pin 2 to the junction of R4 and U1 pin 3. According to the specs for U1, pin 3 will provide up to 15mA. Placing the 600Ω resistor will limit current to 8mA for the external LED (a total of 13mA between the external and OT1x LEDs). I couldn’t find a 600Ω resistor, so I used two 1kΩ in parallel and a 100Ω in series.
OT1x X1 Pin 8 (Change to PWR CONTROL):
I also had no need for the PTT INPUT. I cut the trace from X1 pin 8 to the junction of D2 and D3. Then jumpered pin 8 to JP3 “PTT INPUT OR RELAY OUT”.
OT1x X1 Pin 9 (Change to XMT REQ):
Pin 9 was a no connection pin, so no need to cut any traces, just jumper from JP4 “IRQ”.
Notes:
1. The rating of the switches is inconsequential, except for SW1, which must be rated for as many amps as your rig is going to draw. In my case I used a 10 amp rated switch (for the HTX at high power, though I rarely use it).
2. I wrangled over LED specifics, and ended up using a blue one from Rat Shack, rated at 5 volts and 30 mA. I thought that it might be very dim, but is just bright enough not to blind me at night.
My Diagram (thanks to Juergen and ZL1VFO for the power control):
Config 1 (When I am on my way somewhere)
Config 2 (Destinated - transmits once an hour)
Ok, so I am not the most organized fellow in the world... What counts is the end result... Right? (not according to the XYL!)
I have named this contraption the Octopus!
Another shot of the elusive sea creature...
The console... Not beautiful, but it works...
This shot is upside down. I had originally planned to install it this way, but made assumptions about the switch positions that turned out to be the opposite of what I expected. Hence the 180 degree installation... (Homer would say, "Doh!")
Everything ready to go!
The final installation...
Another shot... OT1x currently controls the HTX-212, but if I unplug it I can plug into the V8000.
With the GPS connected...
Destinated!
If you have any questions please drop me a line!