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_Art_

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    Are You Smarter Than a Garmin Engineer?

    in GPS technology and devices

    Posted · Edited by _Art_

    That might make some sense if you logged the serial output with a serial terminal, and got the screenshot as well.

    The order of the sentences might reveal something. It could even reveal that the error is in the NMEA sentences, and the GPS unit software is the problem.

    I haven’t done this, but expect that devices with USB (and no real serial port) act like their own serial port with the Garmin driver installed in Windows,

    \and could be logged with something like Hyperterminal if the serial port was enabled in the GPS device setup menu.

     

    APRS with Garmin Handheld

    in Ham Radio

    Posted

    I’m guessing that’s an older one that still has a real RS232 serial port.

    The 66, I found out later with help from a fellow on gpsrchive forum, does work,

    but whatever USB adapter used between the 66 USB micro, and serial cable USB mini, has to connect all five USB pins as USB OTG adapters would.

     

    New? Garmin Handhelds

    in GPS technology and devices

    Posted · Edited by _Art_

    Nothing to do with GPS or EPIRBs, and everything to do with physical injury,

    and the fact that crystal oscillators and batteries operate within temperature margins.

     

    Quote

     


    As she descended back down the Star Lake Trail back to the Madison Spring Hut, she would encounter horrific winds. This would slow her down significantly, and cause her to become significantly hypothermic. With hurricane winds, her movement would be extremely slow. It was probably blowing her down many times. She would get up and continue the difficult traverse back to the hut. As she was approaching the hut, she would be blown about 100' downhill from the trail. We are presuming that she had some injuries from being blown over 100 feet in the air. It was 3:30pm in the afternoon. She would then activate her SPOT. Her husband was called, but his cell phone was turned off. Her office would also receive a phone call. The police received a GPS location where she actually was located. For SAR it was an ugly location.

    Please note: There were a number of reports that a PLB was recovered. But, after a long investigation, it was determined that only a SPOT was involved. The final SAR report clearly stated that they only recovered a SPOT. PLB's can handle actual temperatures down to -40F. PLB's can only activated ONCE. We know that she activated the SPOT 11 times. It should be noted that the PLB only sends one signal. The SPOT is capable of transmitting a signal down to -22F. It was colder then -22F that night. 

     

     

    New? Garmin Handhelds

    in GPS technology and devices

    Posted

    inReach is marketed as a communicator, and transmits around 1.6 GHz as satellite phones.

     

    The 121.5 MHz IAD is for aircraft that are already within a tight radius of the beacon location, and already searching.

    There might not be any intelligence sent on the IAD frequency. It’s the 406 MHz transmitter that’s being received by satellites.

     

     

     

    APRS with Garmin Handheld

    in Ham Radio

    Posted

    Back to talk to myself one more time. I got APRS tracking working with the GPSMAP 64st and Yaesu FT-2DR.

    The Yaesu CT-170 data cable was used on the radio side, and the Garmin serial cable on the GPSr side.

     

    Garmin serial cable side -----------> Yaesu CT-170 (with 2.5mm plug cut off) data cable side

     

    Red: (+) DC Power supply for Garmin GPSr. Must be powered for serial port to work

    Black: (-) DC Ground

     

    Green ->    Cable shield (bare wire)

    Yellow (serial Tx) -> Red (Serial Rx)

    White (serial Rx) -> White (Serial Tx)

     

    ___________________________________________________________________________________________

     

    If you don’t want to cut the CT-170 data cable, the plug’s tip is connected to the red wire, the middle ring is connected to white,

    and the ring terminal closest to the plug plastic body is connected to the bare wire sheild, which is ground.

     

    Both devices serial ports are true RS232 level, and can interface with each other safely by direct connection.

     

    If you find, and use this in future please drop a hello.

    Cheers, VK4FAST.

     

     

    APRS with Garmin Handheld

    in Ham Radio

    Posted

    Well if someone searches this in future, I got a USB mini to micro adapter, and tested power & data connections with other devices,

    and the Garmin USB serial cable didn't work with the GPSMAP66 unfortunately.

    I used the same interface setting as in the menu of the GPSMAP 64, and tested various serial baud rates, but saw no signal at all.

     

    Garmin GPSmaps 62s vs Garmin Oregon 600

    in GPS technology and devices

    Posted

    7 hours ago, Atlas Cached said:

     

    The original Oregon/Dakota units had this 'issue' - However, to be perfectly fair (and honest) - how often does one use the GPSr with the screen inverted (facing toward the ground)?

     

     

    That’s the whole point though. With the display facing up, as you’d normally use it, the antenna faces the ground, and all signals it sees are reflected from the ground,

    which would add another few wavelengths to the signal it receives from any satellite. Some vehicle trackers also do this out of necessity, because the car is above them.

     

    I can’t find current model PCBs, but these are Oregon 650 & Montanna 600.

     

    Screen Shot 2019-05-25 at 10.51.49 am.png

    Screen Shot 2019-05-25 at 10.56.18 am.png

    Garmin GPSmaps 62s vs Garmin Oregon 600

    in GPS technology and devices

    Posted

    Can you take an Oregon outside face the display upward, turn it on, go to sat view, get a position,

    then turn it upside down with the display facing the ground and looking up at it, tell what happens?

     

    I’d be interested because all of the “all screen” units use a ceramic chip antenna pointed directly at the ground.

    The displays have a foil backing that would block any signal directly overhead, which is also where the chip antenna’s highest gain is.

     

    With all of the birds in the sky nowadays, it might be beneficial to block those directly overhead. I don’t know.

    It would also be interesting to compare them in some canyon environment where both struggle to get any signal at all.

     

    APRS with Garmin Handheld

    in Ham Radio

    Posted

    Hi :)

    My Garmin USB to serial cable arrived today:

    https://www.ja-gps.com.au/Garmin/nuvi-500-serial-power-cable/

    I’m not associated with this shop, this is just what it is, and where I got it.

     

    The GPSMAP 64 series handheld is supposed to be supported, and I’ve tested it ok with a serial terminal program and real RS232 serial port.

    I suspect 66 series will work with it as well when a USB mini to USB micro adapter (on it’s way) is used, but I've yet to actually test that.

    The cable needs power for the GPS serial port to work, so there must be something active in that little moulded plastic block in the cable.

     

    The overall plan is to have the Garmin plot received locations (any APRS beacons) on the GPS map.

    Garmin specifically supported this for some Oregon and Colorado handhelds:

    https://garmin.blogs.com/softwareupdates/2009/06/aprs-support-in-colorado-and-oregon.html#.XNvowi97Esk

     

    Also some Nuvi support this NMEA serial input, but APRS gets little if any mention after that.

    I’m hoping the GPSMAP 64 and/or 66 are listening for waypoint data over the serial port as well.

     

    Will keep updated.

     

     

     

     

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