added 2-way APRS capabilities

[theksmith]

using my existing tablet and Kenwood ham radio, i only needed to purchase a TNC & cable (~$90) to get APRS up and running quickly and easily. this solution might work for others with a radio and even just a smartphone (Android or Windows only, iPhone guys see this recent post...).

the full article with setup instructions is on my blog: http://theksmith.com/adventures-out...linkd-bluetooth-tnc-android-tablet-aprsdroid/

if you clicked on this and are like "****** is APRS?" - check out the Wikipedia article here... it can work similar to a SPOT satellite messenger, but can do other things as well! specifically i was excited about the 2-way capabilities when out with a group.

 

[Dougherty03]

Yes, the mobilinkd is on my short list to purchase. What is the mount you have for your tablet?

 

[theksmith]

... What is the mount you have for your tablet?

the cradle itself is from RAM Mount, and the dock portion is a hacked up Motorola Speaker Dock accessory.

 

[Crom]

Well done. Any idea if the mobilinkd device supports pairing with more than one device? Phone and tablet perhaps?

 

[theksmith]

Well done. Any idea if the mobilinkd device supports pairing with more than one device? Phone and tablet perhaps?

my guess is only one at a time, but i'm not sure.

 

[Herbie]

I really need to get on this. I have just about all the necessary components except the TNC. Would be really cool to have this working...

 

[theksmith]

a quick bit of soldering and a power cable gets the thing suitable for more permanent vehicle use....

details in the follow-up post ("wiring the Mobilinkd TNC & automatic on/off") here: http://theksmith.com/adventures-out...-automatic-on-off-mod-jeep-tablet-based-aprs/

 

[Crom]

Great work on the PCB power mod. I enjoy your blog entries. Thanks! One thing to be aware of, is the majority of USB power adapter (DC-DC converters) found on the market will produce an abundance of RF noise due to their switching power supplies. This was an issue for me, and it took some time (months) to find the right converter module that did not interfere with 2 meters. For reference, I have the same Kenwood radio. A linear regulator power design of course will not have this problem.

 

[theksmith]

Great work on the PCB power mod. I enjoy your blog entries. Thanks! One thing to be aware of, is the majority of USB power adapter (DC-DC converters) found on the market will produce an abundance of RF noise due to their switching power supplies. This was an issue for me, and it took some time (months) to find the right converter module that did not interfere with 2 meters. For reference, I have the same Kenwood radio. A linear regulator power design of course will not have this problem.

thanks!

i haven't noticed noise with the hardware adapter i happened to get so far, but good info. now i'm going to have to pop it open and see what it's using! it was sold as a buck converter but that's all i know (i've read that type of circuit can inject input and output noise depending on the exact type).

i have had experience with really cheap regulator circuits causing me to pull my hair out before - i once had one that was slowly sinking below the claimed output which caused the stuff i was running off it to just start randomly failing. i spent too long thinking it was an intermittent wiring or solder point issue!

 

[Crom]

The RF noise is subtle, in that all it does is raise the noise floor +20dB! It makes the receiver almost deaf, as it looses sensitivity. Check out this blog entry, and this video, precisely what I was experiencing with all of the BUCK and DC-DC converters I tested. https://www.youtube.com/watch?v=Wvz4uu5opLg

 

[robgendreau]

I realize you're getting GPS via the Android device, but is there a way to attach a GPS using any of the ports on the TNC? or BT?

 

[theksmith]

I realize you're getting GPS via the Android device, but is there a way to attach a GPS using any of the ports on the TNC? or BT?

not with this TNC - it's a pretty specific to being used with smartphones/tablets.

one of these company's products would probably work better for you:

http://www.byonics.com/tinytrak/
https://www.argentdata.com/products/aprs.html