Sorry this has taken so long, I was going to post this about 2 weeks ago, but I have been refining and upgrading. Now that I have the system running I will share. I have been wanting to do an APRS rig in the truck for quite a while and have not had the funds to do it. A couple of weeks ago Derek Shared this video
[video=youtube_share;8-9_8HVkvgc]http://youtu.be/8-9_8HVkvgc[/video]
If you dont want to watch the video, I will sum it up now and give you the details later. In short, you can plug your old cell phone (just needs gps no plan or data) into your cheap radio and have aprs via afsk output to vox input. (details later)
I immediately thought, I am cheap, but I can come up with $30 and I already have a Samsung Galaxy Tab in the truck that I use for navigation. Within a few minutes I was well on my way to the $30 budget for this project by purchasing 2 Baofeng UV5R radios off of Amazon for $30.17 each ($60.34 total)
I already had a 3.5 mm to 3.5mm phono cable and already had APRSDroid so i just had to wait for the delivery..
Since I had time to kill, I went ahead and set up the app. It is pretty simple, for the connection type select AFSK, and pretty much everything else is optional.
When the radios came in I plugged everything together, went into the menu on the radio and set it for a freq step of 2.5, and turned vox on to lvl 10 (what the video recommended) then set the radio to the proper freq of 144.390 Went to APRS droid and hit start tracking. The radio lit up right away telling me it was transmitting so it was off to openaprs.com to see if it worked. To my surprise, I was on the map.
I was very excited, but now I wanted more. I wanted to see other people on the map, not just transmit. This lead me to Google, and lots of reading about parts of APRS I will probably never understand, but I did find the information I needed. APRSDroid will listen, which means I needed to get the audio output of the radio back into the tablet. The problem is the radio uses a 2.5mm phono plug for the speaker and the 3.5 for the mic while the tablet only has one 3.5mm jack. The Tablet and most phones use what is called a TRRS jack (Tip, Ring, Ring, Sleeve) That means that it has an extra connection from your standard stereo phono plug so it can do audio output and mic input on one plug at the same time. This means i need to make a cable to get from the single plug on the tablet to the 2 plugs on the radio. So I ordered up a 2 pack of TRRS connectors off of ebay for $5.50 (total now $65.84) and was planning on cutting the plug off of the headset that comes with the radio to make my cable. Then I got lazy so it was back to the internet. My first stop was to Monoprice where I found this. It is designed to split the TRRS plug so you can use headphones and a mic with an ipad. $11.76 with shipping (total $77.60) I happened to have another 3.5mm to 3.5mm cable and got a 3.5mm to 2.5mm adapter from work. Surprisingly it worked, I could see people on my map, and I could transmit.
Again, I celebrated, but this lead me to 2 problems. The first is it looked like this
and in the truck
The second problem is APRSdroid uses Google Maps, but does not have a way to cache the maps, so as soon as I drove away from my wifi, I was seeing people on a blank map.
More reading and I found that this problem has been addressed, and is easily fixed. From the aprsdroid website, you can download a modified apk which allows you to use different map sources, and even links you to free maps that can be used. The instructions are pretty clear on the website so I will just give you the link instead of retyping it. aprsdroid.net/osm
I was now up and running with 2 way communication, a working map and an ugly tangle of cable.
Time for google again which lead me to a video that pointed out some flaws with this setup, and a solution to that flaw that also solves my ugly cable problem. Unfortunately I cant find the video but it basically said that while aprsdroid is listening to receive information it has no problem interrupting the incoming info if it decides it is time to transmit. This makes it unreliable as it is fighting itself, and it is also causing lost information for the entire aprs system. The solution the video suggested is a bluetooth TNC made by http://www.mobilinkd.com/ The TNC itself is $49.95 plus $9.95 for a much shorter cable. With shipping this was $69.90 (total $147.50)
Well, this setup came in today. It is pretty, it is small, and was simple to setup. Turn off vox on the radio, plug cable into radio and TNC. Hit the button and watch the pretty blue light on the tnc flash, then pair up the bluetooth (code 1234) Then in APRSDroid, change the connection from AFSK to Bluetooth, then in connection settings select the mobilink tnc hit start tracking.
The system is running faster, wirelessly, and is getting into the system reliably
The TNC sitting next to the Baofeng UV5R
The tnc "mounted" to the radio
the other view of the "mount" I will probably remove the clip and just velcro it to the back of the radio
One change I would recommend (because I read it) is to change the digipeater path. By default APRSdroid uses WIDE1-1 I changed it to WIDE1-1,WIDE2-1 and it does seem to work better. There is a lot of really detailed information on what that means, but the site that made it so I understood it was http://wa8lmf.net/DigiPaths/NNNN-Digi-Demo.htm
Here are some extra photos
Me on the map (KJ6DZZ)
other aprs systems that I am recieving
the connection log showing the "raw data" in and out of the system
[video=youtube_share;8-9_8HVkvgc]http://youtu.be/8-9_8HVkvgc[/video]
If you dont want to watch the video, I will sum it up now and give you the details later. In short, you can plug your old cell phone (just needs gps no plan or data) into your cheap radio and have aprs via afsk output to vox input. (details later)
I immediately thought, I am cheap, but I can come up with $30 and I already have a Samsung Galaxy Tab in the truck that I use for navigation. Within a few minutes I was well on my way to the $30 budget for this project by purchasing 2 Baofeng UV5R radios off of Amazon for $30.17 each ($60.34 total)
I already had a 3.5 mm to 3.5mm phono cable and already had APRSDroid so i just had to wait for the delivery..
Since I had time to kill, I went ahead and set up the app. It is pretty simple, for the connection type select AFSK, and pretty much everything else is optional.
When the radios came in I plugged everything together, went into the menu on the radio and set it for a freq step of 2.5, and turned vox on to lvl 10 (what the video recommended) then set the radio to the proper freq of 144.390 Went to APRS droid and hit start tracking. The radio lit up right away telling me it was transmitting so it was off to openaprs.com to see if it worked. To my surprise, I was on the map.
I was very excited, but now I wanted more. I wanted to see other people on the map, not just transmit. This lead me to Google, and lots of reading about parts of APRS I will probably never understand, but I did find the information I needed. APRSDroid will listen, which means I needed to get the audio output of the radio back into the tablet. The problem is the radio uses a 2.5mm phono plug for the speaker and the 3.5 for the mic while the tablet only has one 3.5mm jack. The Tablet and most phones use what is called a TRRS jack (Tip, Ring, Ring, Sleeve) That means that it has an extra connection from your standard stereo phono plug so it can do audio output and mic input on one plug at the same time. This means i need to make a cable to get from the single plug on the tablet to the 2 plugs on the radio. So I ordered up a 2 pack of TRRS connectors off of ebay for $5.50 (total now $65.84) and was planning on cutting the plug off of the headset that comes with the radio to make my cable. Then I got lazy so it was back to the internet. My first stop was to Monoprice where I found this. It is designed to split the TRRS plug so you can use headphones and a mic with an ipad. $11.76 with shipping (total $77.60) I happened to have another 3.5mm to 3.5mm cable and got a 3.5mm to 2.5mm adapter from work. Surprisingly it worked, I could see people on my map, and I could transmit.
Again, I celebrated, but this lead me to 2 problems. The first is it looked like this
and in the truck
The second problem is APRSdroid uses Google Maps, but does not have a way to cache the maps, so as soon as I drove away from my wifi, I was seeing people on a blank map.
More reading and I found that this problem has been addressed, and is easily fixed. From the aprsdroid website, you can download a modified apk which allows you to use different map sources, and even links you to free maps that can be used. The instructions are pretty clear on the website so I will just give you the link instead of retyping it. aprsdroid.net/osm
I was now up and running with 2 way communication, a working map and an ugly tangle of cable.
Time for google again which lead me to a video that pointed out some flaws with this setup, and a solution to that flaw that also solves my ugly cable problem. Unfortunately I cant find the video but it basically said that while aprsdroid is listening to receive information it has no problem interrupting the incoming info if it decides it is time to transmit. This makes it unreliable as it is fighting itself, and it is also causing lost information for the entire aprs system. The solution the video suggested is a bluetooth TNC made by http://www.mobilinkd.com/ The TNC itself is $49.95 plus $9.95 for a much shorter cable. With shipping this was $69.90 (total $147.50)
Well, this setup came in today. It is pretty, it is small, and was simple to setup. Turn off vox on the radio, plug cable into radio and TNC. Hit the button and watch the pretty blue light on the tnc flash, then pair up the bluetooth (code 1234) Then in APRSDroid, change the connection from AFSK to Bluetooth, then in connection settings select the mobilink tnc hit start tracking.
The system is running faster, wirelessly, and is getting into the system reliably
The TNC sitting next to the Baofeng UV5R
The tnc "mounted" to the radio
the other view of the "mount" I will probably remove the clip and just velcro it to the back of the radio
One change I would recommend (because I read it) is to change the digipeater path. By default APRSdroid uses WIDE1-1 I changed it to WIDE1-1,WIDE2-1 and it does seem to work better. There is a lot of really detailed information on what that means, but the site that made it so I understood it was http://wa8lmf.net/DigiPaths/NNNN-Digi-Demo.htm
Here are some extra photos
Me on the map (KJ6DZZ)
other aprs systems that I am recieving
the connection log showing the "raw data" in and out of the system
