Asus MyPal A686 PDA with GPS
Introduction
The last summer I decided to buy a GPS device for these purposes:- car navigation
- view my position on mountains maps when I go hiking
- track hiking path and viewpoints
- handheld GPS devices are usually designed for sport purposes, where the need for accuracy is much more critical than what is required for car navigation, so they tend to be more accurate than regular gps receivers that can be found on PDAs; for instance, many handheld GPS support WAAS/EGNOS while most PDAs don't, and their gps signal under trees is stronger than average.
- handheld GPS battery life is much longer than PDAs (15-25 hours vs 4-5 hours)
- the most recent and advanced handheld GPS cost too much (they start from 350 Euro), while cheap ones have very limited features and storage capability; instead in the PDA world I found some recent models that are more affordable (250 to 300 Euro) and have plenty of features.
- PDAs can be used to do many things other than navigation support or path tracking; before buying you should identify which features you really need. As for me, taking notes, reading documents, maybe editing source code, all stuff that requires only a text editor and a pdf reader.
- handheld GPS devices have their own software, while on a PDA I can install the software I want: TomTom or Route66 or Navigon for road navigation, Odgps or WinGPS 4L for hiking purposes, etc.
I easily chose to buy a PDA with GPS instead of a handheld GPS because the choice of the software and the opportunity to use it for other purposes than navigation only were very important to me, nonetheless I didn't want to spend more than 300-350 Euro.
Given this limited budget, the choice of the PDA was quite restricted: the MITAC Mio P350 and P550 and its twin Airis T620, the i-mate PDA-N, HP Ipaq RX 5720 and the Asus MyPal A686, A696 and A639. I initially reduced the choice even further to models with 802.11g (54 Mbps) wireless: the Asus A696 and A639 and the Mio P550. Searching on the net, I discovered that there is a defective lot of Mio P550 coming with an unstable GPS signal, while the Asus MyPal A639 has some problems regarding screen alignment. Instead the A696, the Asus newest model, other than having no known problems, impressed more than a reviewer (for instance, mobile-review.com) for its battery duration, which allows usage for 5 hours when the gps is active and more than a day if it's used for reading only; it's nothing, compared with the 40 hours (yes: fourty) of my former 1997 Psion 5, but it's quite enough for most of my hiking sessions: if the purpose is to follow a map, it's not necessary to always keep the PDA switched on; if the purpose is to track the path, it can be used in 10 hours hikes too, 5 hours to go and 5 to come back (the path is tracked only on the go or on the return).
I was finally quite decided to buy the Asus MyPal A696, but the few shops where it was available were selling it at more than 350 Euros; my holidays were approaching and I found the A686 for 276 Euros in an online shop I trust.
What are the differences between the A696 and the A686? Shall I wait to find the A696 or take the A686 now?
- The A696 has a 416 MHz processor vs the A686 312 MHz, a 25% faster. For navigation purposes, 312 MHz are more than adequate.
- The A696 has 256 MB ROM vs the A686 128 MB. Both are too little for navigation maps and 128 MB allow to install many applications; anyway, applications can be installed on the SD card without suffering slow performance.
- The A696 has wireless capability, the A686 has not. But what would I really need it for? Having a wireless router, it seemed quite foolish to buy a pda without wireless capability, but on a second thought I realized that the screen is too small for surfing the web and there are no wireless points in my area, so I would have used it only to transfer files from and to my pc in place of the usb cable.
Therefore I bought the A686.
Package
The package includes:- USB cable
- 2 stylus
- car kit (holder and gooseneck)
- AC adapter
- car charger
- protection case
- obviously, Asus MyPal A686 and its 1200mAh Li-ion battery
- paper user guide, warranty and MS ActiveSync CDROM
Pictures
Note: The other PDA in the comparison pictures is the Asus MyPal A636N.
Features and performance
The Asus MyPal A686, together with its big brother, the A696, is the last model of Asus A600 series PDAs, whose specifications you can see compared here (pdadb.net). It's a bit smaller than the A636N, its predecessor, especially in height, and its dimensions make it comfortable to keep in the hand or in the pocket: neither too large nor too small, and not heavy. I kept it in my hand during the first walk to check every now and then my position and the only discomfort I had was to have my hand occupied; I didn't find it so heavy or so large that I would feel the desire to put it in my pocket or waist pouch. I am a bit discomforted with its size only when I sit with the A686 in my pocket because its length make it push against my stomach.
The processor is a 312 MHz Intel Xscale, memory is 64 MB RAM + 128 MB ROM. The speed of the cpu is quite limited but the only slowness I found is loading the pdf reader, PocketXpdf; while some users experienced slowness problems using TomTom navigator on older PDAs, on my A686 it runs smoothly. A reviewer found the A686 and A696 performance better than other PDAs with the same specifications and speculated that Asus optimized these models for usage with Windows Mobile.
Indoor the GPS receiver usually doesn't get the first fix, it's necessary to go outside or on a balcony. Outdoor it takes some minutes to view the satellites and obtain the first fix: sometimes it requires even more than 10 minutes, other times it gets it in 2 minutes. That depends on how long the GPS has been disabled and how far is the current location from the last location I used the GPS: technically speaking, a cold start requires about 10 minutes, a warm start 2 minutes.
Once the A686 gets the fix, it doesn't lose it easily; for instance, if I was outdoor and I enter a building, usually the gps communication is maintained; until now the only occasions I lost the fix were when I entered a tunnel.
When I switch off the PDA while the GPS is active and then I switch it on again, the A686 gets the fix in a matter of seconds; the same happens when the fix is lost entering a tunnel and then I exit the tunnel. This is very useful, especially when there is an intersection after a tunnel or when I walk on the mountain and I switch on the PDA only when I need to consult the map, keeping it switched off for most of the journey, to spare the batteries.
Talking about batteries, the expectations I had after reading some reviews have been totally fulfilled: last August I went to do some trekking and I used the A686 to first consult a map I got from Google Earth to reach my destination and then to track my path on the journey to come back. In that occasion I was able to use the pda, with the gps receiver active, since 12:00, when I disconnected it from the car adapter, to 18:00, taking a 1-hour pause for me to eat and rest and for the pda to spare the batteries. That makes a full 5-hour autonomy with the GPS active and as little processor usage as it's needed by WinGPS 4L Mobile and odgps. What makes the PDAs with GPS amazing is that after trekking I plugged the A686 in the car lighter and I used it as a car navigator.
Backlight is quite good, but when the sun is high and strong I have to make a shadow over the screen (with my hand or with my body) to see the map, especially if it has dark colours, like maps taken from Google Earth (TomTom maps with the default colours are much more visible). 
The process to change the backlight brightness is quite long and annoying to do when the screen is difficult to read: Start, Settings, Systems, Backlight; but fortunately Asus provided the Asus Status icon on the bottom right angle of the screen (the red "A"): tapping this icon a menu appears, and a tap on the Backlight item will open the backlight settings, where the backlight brightness can be increased or decreased. The Psion 5 comes to my mind again because the backlight could be activated simply pressing two keys (it had a keyboard and the backlight settings were only "on" and "off"); a good solution for the Asus MyPal models could be providing backlight settings as a function to be assigned to one of the customizable buttons and then using the navigation button to increase or decrease the brightness level - AsusTek, are you reading?
The A686 comes with two pens, a good thought by Asus; even if I never lost my previous Psion 5 pen, I understand how easy is to lose it. When the A686 is used vertically, the pen is located horizontally in the bottom side, coming out from the bottom right corner; when used horizontally, the pen is in vertical position and comes out from the top right corner. This way the pen can't come out by itself. Moreover, the pen makes some resistance when it's pulled out because when it's inside the pda it's shortened: the upper half of the pen goes inside the lower part, so that when I pull out the pen the upper part comes out of the lower part first, extending the pen, then it stops and I have to pull again to make the lower part coming out of the silo. I think it's almost impossible for the pen to come out accidentally.
The A686 has a navigation button (the large circular one at the center), with 4 functions (move up, down, left, right), a confirm button (that at the center of the navigation button) and four additional buttons whose functions can be customized in Start, Settings, Buttons; they are numbered, from left to right, as this: 3, 4, 1, 2. There are many functions that can be assigned to a button:
- open one of the installed programs
- go to today
- rotate screen (one of the most useful functions)
switch between open applications (another one of the most useful functions); there's a lag since when I press the button to when the icons of the programs appear, but it can be changed to as low as 0.5 seconds in Start, Settings, Mode switcher- move in one direction
- display keyboard
- ok/close
The HOLD button, that locks the PDA to avoid accidental pressure of buttons, is located on one of the longest sides of the A686. Unfortunately, in this position it could be accidentally switched to the HOLD position when putting the A686 in its protection case: this is what happened to me once and made me lose some hours trying to figure out what the problem was (I had already forgot there was a HOLD button, and I was already suspecting a failure of the PDA), until I "accidentally" saw the HOLD button and breathed a sigh of relief.
The car cradle can be attached to the windshield using the gooseneck sucker. There is a locking mechanism which helps the sucker to always be firm against the glass: that avoids that an accidental hit on the cradle with the hand or a road bump taken too fast would make the sucker lose its grip and fall with the cradle and the pda. Moreover, the hard to flex gooseneck makes sure the position of the pda can't be accidentally moved from the supposedly well studied position the driver placed it when mounting the gooseneck and cradle.
On the contrary, the 12v adapter seems cheap and it doesn't plug firmly in the car outlet: taking some bumps or fast turns it happened it came out.
GPS accuracy
The precision of a path tracked using GPS data and the accuracy of the current position displayed on a map by a navigation software depend on many factors (accuracy of the gps receiver, correctness of the map, precision of the software that uses gps data) and it may be good for some people as long as it may be insufficient for others. Here are some examples of such accuracy or inaccuracy:
- I live at 315 meters above sea level. VisualGPSce sometimes reports 350m a.s.l. in the first minutes after satellites acquisition, then it stabilizes at the correct altitude.
- This is a route I made by car, as measured by Odgps and saved as gpx, converted by GPSBabelGUI to kml and opened in Google Earth.
This image is an example of how much data is collected when traveling by car, with data poll set at 1000 ms, turn rate at 10° (gps points are stored when a 10° or more direction change has been detected), track rate at 10 seconds (gps points are stored every 10 seconds even when direction doesn't change) and speed ranging from 30 to 70 kph.
Changing data poll to 500 ms and turn rate to 3°, much more data is collected and the track is much more accurate:
The two lines are the gps tracking of the same path that I covered at two different moments in the same direction and with identical settings.
With data poll set at 1000 ms and turn rate at 3°, the tracking is this:
It seems that changing data poll doesn't affect the accuracy of the track, at least not as much as weather condition and satellite position do, instead turn rate is a fundamental parameter to change when a better accuracy is needed. - Traveling by car, the current speed reported by TomTom has a little lag but it's understandable because the speed is calculated comparing the position of the car at two different moments; if I accelerate, at moment 2 I see the average speed between moment 1 and 2, and not the real speed at moment 2; nonetheless, the position as measured by satellites has an approximation of a few meters. In rotary intersections with many roads the high accuracy of the gps allows TomTom to draw the current position on the exact road I take; nevertheless, since TomTom rotates the map while the car turns to always have the current direction arrow pointing towards the top of the screen, such rotation of the map, matched with the little lag in showing the current position, could be deceptive on the road that I've just taken: while I am taking the third exit TomTom direction arrow is still drawn as if I am taking the second exit. I think that if TomTom waited to rotate the map for a few meters after the intersection it would be much better.
- Using the same data poll (1000 ms) and turn rate (10°) I used to track the path while driving my car, tracking a walking path is obviously much more precise: simplifying, if the position is checked once a minute and I make 1 km in 3 minutes, I get 3 points to describe a 1 km path, while if I make 1 km in 15 minutes I get 15 points to describe the same 1 km path. Even turns are much more precise because changes of directions are slower when walking than when driving.
- Google Earth images are not perfectly aligned with GPS data:
In this image it's quite evident that the path recorded by the A686 gps (the red line) differs from the satellite image by 50 meters at least. I think it depends on 3D terrain used by Google Earth to display images in three dimensions. - In the most covered woods GPS devices have problems receiving satellites signals; I didn't test the A686 in the rainforest, but I walked through some woods and I didn't experience any loss of GPS signal.
Troubleshooting
- To make a software reset (reboot Windows Mobile), press the RESET button
- To make a hardware reset (delete everything), press simultaneously the RESET button and the button at the center of the navigational buttons - I never needed to try it
- Activesync transfer bar seems to loop during transfers of large files: the progress bar reaches the end and restarts from the begin multiple times; it doesn't mean something is wrong, it just means the transfer is in progress, and the progress bar will repeat its left-to-right cycle multiple times until the transfer is complete; to be sure the transfer succeeds, check in the destination folder if some of the files have been transferred
- If the A686 is switched off and pressing the power button nothing happens, and then pressing the reset button the blue Asus screen appears but just after that the A686 switches off, maybe the HOLD button is in HOLD position
- Problems with SD cards larger than 4 GB: there's a patch on Asus support site, and Asus A686 forum is a good place to start (check A696 forum too)
- Sometimes TomTom doesn't get the fix even after more than 10 minutes: I noticed that if I close TomTom and start VisualGPSce, and then I wait for a few minutes for it to get the fix, then just as I close VisualGPSce and open TomTom, the gps signal is available right away.
- If you changed some SIRF or NMEA parameters and the A686 doesn't get a fix anymore, maybe something is misconfigured. That happened to me and I solved with SirfTech (thanks to the user dorcon of the Hardware Upgrade forum):
- go to Comm and check if the port and baud rate are correct (Find Port & Baud)
- see which protocol is set (NMEA o SIRF), then check if Bad bytes are 0
- if the protocol is NMEA, go to NMEA, Set Serial Port (Switch to SiRF), set SiRF as protocol and the correct baud rate, click Set; then follow the next step
- if the protocol is SIRF go to SiRF, Switch to NMEA Protocol, set the correct baud rate and tap Set
SirfTech Comm settings
SirfTech Switch to NMEA Protocol
Conclusion
Even though the Asus MyPal A686 is slower and has half the memory of its more desired big brother, the A696, its hardware is more than adequate for regular PDA and navigation tasks. The gps is accurate enough, sometimes cold starts are slow but warm starts usually require less than 2 minutes. The battery autonomy is above average. The package is complete for people who want to choose the navigation software: to start using the A686 as a car navigator, a SD card and the navigation software must be bought too.
With a price of 276 Euro when the A696 costs 295 Euro, it's quite expensive and I would have bought the bigger brother if it was in stock. However, after 6 months of use I have nothing to complain about the A696... for now.
Posted by: z24 | Sun, Dec 09 2007 |
Category: /hardware |
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