Why using a smartphone GPS can work, but what not to do when using it as a GPS.
This is more a cautionary tale than a detailed "how-to" guide on using a smartphone as a GPS. It is my tale of woe losing my recently purchased smartphone to water penetration in Slovenia late last year.
Others on this forum have previously posted about using various phones (iPhone/Android) with offline Topo GPS apps for GPS navigation.
I am a convert to using Oruxmaps and an Android smartphone with a good GPS chipset with quick signal acquisition. There are certainly easier apps to use than Oruxmaps, but even though I use only a fraction of what it can do, I have been really pleased with it for the past 12 months or so.
I was travelling late last year in Hungary, Croatia and Slovenia, and I noticed the various offline phone based OSM maps I used matched the paper versions of 1:25k and 1:50k that I bought. These OSM maps were sometimes more accurate than my Garmin's European Recreational topo (1:100k) maps or Garmin's AdriaTopo V3 topo (1:25k) that I also had on my Garmin handheld GPS unit.
The OSM maps I used had the trails, huts, caves and logging tracks marked as well. Handy to find the refuge caves for a couple of overnighters in Hungary (not included in the Garmin Adriatopo mapset). Additionally some of the paper maps I bought have a QR code printed with the hut info, so when I had data connection, I just scanned the QR code and it shows details of the hut (opening season, contact info, details etc) and the GPS coordinates then easily copied and pasted to Oruxmaps app and saved as a waypoint - although most of the huts were already marked on the OSM map.
I also have Oruxmaps on my 7" android tablet, and have been using it to plan GPX trails and then copy the GPX files to my Garmin Oregon GPS.
This has been working really well, so before my travels began last year I bought a smaller cheapish Android phone for travel and to use Oruxmaps. The phone, a cheap Xiaomi Redmi 3, was great. The battery life was awesome - I got more life on a single charge than I would from my Garmin Oregon 600 on a set of AA NiMH batteries. There was a compromise however, in tracking mode, the recorded GPX trails on the Redmi 3 did show a bit more GPS drift when compared with either my 7" tablet or my Garmin Oregon. But for navigation purposes the accuracy was adequate. All this was done in fully offline mode with pre-loaded maps (no wifi, no mobile data).
I did not use the phone's Oruxmaps in track recording mode, and had the track recording done by my Garmin Oregon 600 GPS instead.
These are a few pictures of it working fabulously in Hungary showing the routes I created on Oruxmaps and transfered to my Garmin.
The sparseness of the detail in the Garmin is quite immediate in Hungary as I only had 1:100k maps on my Garmin. A few times I went off my prepared route, to go up to peaks to see if I could see anything, and a couple of times I did get lost when I got disoriented in the fog. This was the view at one of the ridges standing at a cliff where on a clear day you should have been able to see the surrounding hills. So GPS certainly came in handy to find my way back on track.
When I reached Slovenia, it became evident that I would struggle to do mountain walks late in the season in November due to the early snow, I resigned myself to walking the lower hills instead.
One day in the first week of November, near Bled, I set off before sunrise and the weather forecast was for a bit of rain but not too cold. It doesn't look it but it was fairly steep at this section and the drizzle (with drops on my camera lens visible) meant that I didn't take my camera out much.
About lunchtime the rain started in earnest, and I hunkered down at about 1000m to eat my sandwich. About an hour later however, there was thunder and lightning which wasn't forecast, and I decided to get off the mountain side as quickly as I could.
This is where my tale of woe started. In the morning it hadn't been raining enough for me to put my phone into it's waterproof case, so I put it in my softshell chest pocket. I had donned my goretex rainshell over it and promptly forgot about the phone as I tried to get off the mountain quickly. The rain came down so heavily that some paths turned into rivers.
This is what one of the paths close to the end of the trail looked like.
The trail "river" was rushing so much part of the track at a tree root collapsed and became a little waterfall. Looked pretty - but about 2 metres after this I slipped on the wet leaves and mud and left a nice butt slide imprint in the ground, and me with mud all down the back of my pants and the back of my goretex shell.
Halfway down, I checked my Garmin Oregon GPS (in my hipbelt pocket) as I took a different route down on the other side than I took going up. In the pouring rain the touchscreen can be difficult to use. It was only then I remembered my phone. After unzipping my goretex jacket and reaching into the softshell chest pocket, I realised that my sweat/condensation had made my softshell dripping wet and the phone was wet as well. It probably didn't help that the outer goretex layer was saturated so the water vapour couldn't escape. There wasn't much I could dry it with, so I wrapped it in a handkerchief, put it back and concentrated on getting off the mountain.
By the time I got down and to shelter, where I could dry off the phone, I found the damage had been done. The phone wouldn't turn on. The next few days after attempting to dry off the phone I found it would turn on but the touchscreen was not working.
It was a few days later when I managed to get it to a repair shop that I was informed that it was likely the touchscreen element was dead. It was turned on when the water got in, so it must have shorted something. It wasn't worth replacing the touchscreen as that might not have been the only thing to be damaged, and the cost to repair versus the cost of the phone didn't justify it being repaired there or claiming it on insurance.
So in concluding - I think nowadays smartphone GPSs with the right software can work very well, as long as you can waterproof and protect it from impact damage.
There are some other advantages of using a smartphone vs a dedicated handheld GPS device - like the additional wireless communication features, and online features. For example, on smartphones with some apps if you have a connection data you can download OSM topo maps or DEM (Digital Elevation Model) files "on the fly" to be saved on the phone for later offline use. So far on most dedicated handheld GPS devices, you still have to download the file to a PC or device then copy it to the sd card or the handheld GPS.
Now there are also various waterproof and water resistant phones also out in the market place now (like the later iPhones and various android manufacturers), and there are also some newer "hardened/rugged" devices being released. If more manufacturers get on board and release toughened devices, I think that the dedicated Handheld GPS unit will certainly come under increased competition.
Just remember my tale of woe, however, if you decide to use a smartphone as a GPS navigator. If you don't have a waterproof/toughened device, you'll want to get a case that can offer that protection.
In my example, I think even a simple ziplock bag would have prevented the loss of my phone...