Thanks Larry and Scott for your collective wisdom. The power cable I built seems to work fine, I would just need to tie it in the DB9 end of the power conversion version of the data cable. I have a crimper so that is the easy part.
I'll put in the order next week. But, for my own education, is there a schematic for this sort of thing? On 21-Aug-09, at 1:33 AM, Scott Miller wrote: > The wiring for the T2-301 is the same as the OT2m if you use the > yellow > serial+power cable. You wouldn't be able to run the Garmin cable > alone > since it doesn't provide power. > > Scott > > k7ybz wrote: >> >> >> Erich, >> >> I forgot to add that you can have Scott add a DB-9 connector to that >> Garmin cable in the checkout. Just make sure you mention it is for a >> T2-301 as the pinout is different than an OT2. >> >> Larry >> K7YBZ >> >>> >>> Erich, >>> >>> To connect between the Nuvi 350 and the OT2 you need a USB to RS232 >> converter. You can make one by using diodes and resistors (look in >> the >> files section of the tracker2 group) or you can buy the Garmin >> version >> from Scott. The Garmin part number is 010-10813-00. Here is a link to >> Scott's page: >>> >> https://www.argentdata.com/catalog/product_info.php?cPath=28&products_id=90 >> <https://www.argentdata.com/catalog/product_info.php?cPath=28&products_id=90 >> > >>> >>> Larry >>> K7YBZ >>> >>> >>> --- In [email protected] <mailto:tracker2%40yahoogroups.com>, >> "Erich J. Ritzmann" <ejritz@> wrote: >>>> >>>> >>>> You are correct -- with the "powered cable", I was indeed >>>> referring to >>>> the yellow cable. And, looks like I overlooked the bit about >>>> voltage >>>> differences. >>>> >>>> A pair of (series?) diodes & (series?) resistor, designed to drop >>>> the >>>> voltage from the output of the T2-301 from 5 to 3.3vdc. >>>> >>>> But going the other direction, would 3.3v be enough to be >>>> readable by >>>> the T2? >>>> >>>> The only cable that came with the Nuvi looks like a normal USB >>>> with a >>>> normal connector on one end and a USB-b "mini" on the other -- is >>>> that >>>> the one you are referring to? I can certainly cannibalize that. >>>> >>>> -- >>>> ER >>>> >>>> On 20-Aug-09, at 12:44 AM, Scott Miller wrote: >>>> >>>>> Ok, back up for a minute. What cables are you using? Are you >>>>> connecting directly to the T2-301, or are you using the yellow and >>>>> black >>>>> cable? >>>>> >>>>> The nuvi needs 3.3v levels. If you're connecting it to a T2 of any >>>>> type, you need to either use the Garmin cable with the level >>>>> shifter >>>>> built in, or use a couple of diodes and a resistor to limit the >> output >>>>> level. >>>>> >>>>> Scott >>>>> >>>>> va3xto wrote: >>>>>> >>>>>> >>>>>> I wired up a T2-301 with a powered cable using two USB-b >>>>>> connectors. >>>>>> >>>>>> Serial pins 4&5 supply power to pins 1 &5 of USB-b-B (5 vdc power >>>>>> on back) >>>>>> >>>>>> Serial pin 2 connects to pin 3 on USB-b-A (FMI on side). >>>>>> Serial pin 3 connects to pin 2 on USB-b-A (FMI). >>>>>> >>>>>> 8.06k measured resistance between ground and USB-b-A pin 4 brown. >>>>>> >>>>>> The Nuvi gets power from the back, no problem. Disconnecting back >>>>>> yields >>>>>> serial device must have power, yada, yada. >>>>>> >>>>>> The GPS is working based on the map it displays on the Nuvi >>>>>> itself. >>>>>> >>>>>> The T2-301 doesn't seem to send any data using the Nuvi. (And, >>>>>> transmitting packets nearby from another machine does not >> display the >>>>>> expected waypoint.) >>>>>> >>>>>> Before plugging in the Nuvi, I had the T2-301 transmitting APRS >>>>>> packets >>>>>> using the ADS-GM1 GPS. >>>>>> >>>>>> Any ideas what I am missing? >>>>>> >>>>>> >>>>> >>>>> >>>>> >>>>> ------------------------------------ >>>>> >>>>> Yahoo! Groups Links >>>>> >>>>> >>>>> >>>> -- >>>> Erich J. Ritzmann >>>> >>> >> >> > > > > ------------------------------------ > > Yahoo! Groups Links > > > -- Erich J. Ritzmann
