A calibration is important for all devices which have a touchscreen. Because of calibration, the device can recognize where exactly you are tapping. In the most cases, the standard calibration program is sufficient for Palm PDAs. But if your Palm is older than 2 years, you often have problems with digitizers, sometimes even earlier. In my case, I calibrated my screen again and again, but the recognition of my touchscreen was very inaccurate. Especially the lower parts of the touchscreen were my main problem. I had almost no chance to tap onto the buttons in the lowest line (for example “Done”, “New” and “Delete” in the Note Pad). And sometimes, I couldn’t even finish the calibration.
So I had a look at PowerDigi, a calibration tool by Dmitry Grinberg (Palmpowerups.com). It uses special technologies and algorithms in order to make the recogntion of touches more accurate. Dmitry told me that even owners of Palms with cracked touchscreens may have a chance to use their device again.
There are three versions of PowerDigi (PowerDigi320, PowerDigi440 and PowerDigi480). The first version is for devices without Graffiti area (Tungsten C, Treo smartphones, …). The second one is for devices with a Graffiti area (Tungsten E2, Zire 72). The third will run on PDAs with a 320×480 screen (Palm TX, LifeDrive, …). The user interface of PowerDigi is very easy to use. There is one button for calibrating the screen and one to test the digitizer. Using the checkbox “Enabled”, you can enable PowerDigi’s calibration.
When you start it for the first time, you have to calibrate your screen before PowerDigi can be activated. There are three calibration modes. The first one (“fast”) needs 12 taps, the second one (“medium”) 35 taps and the third one (“accurate”) 70 taps. The more taps you make the more prober is the calibration. This is the first reason why PowerDigi can help you: Palm’s calibration tool only needs three tabs.
According to the developer, the “fast” or “medium” mode should be enough in the most cases. Only if your digitizer is almost completely broken or even cracked, you may need the “accurate” calibration.
Tapping the screen 30 times and more at special positions can be very annoying. But the developer had a good idea: if you tap at a wrong position, you can repeat this tap by pressing the down button. By pressing the up button, you can cancel the calibration. I also see the second pro of PowerDigi: Palm’s calibration tool will not save your calibration if it “thinks” that the position you tapped at is too far away from the target. But this may happen if your screen is old or broken. Then you even cannot exit the calibration. In my case, I either had to do a softreset or to tap 3 mms to the left of the target so that Palm’s tool accepted the calibration (which was, of course, very decalibrated). In contrast to that, PowerDigi accepts every tap you make, no matter where you tap and where the target is.
This may help owners of broken screens, but can also be dangerous. I tried this feature and made a completely wrong calibration (e. g. when the target was in the upper part of the screen, I tapped into the lower, ..) and in this case, you cannot use your screen because PowerDigi takes your wrong calibration. Even Palm’s calibration tool could not help. So I did a warm reset and deleted PowerDigi’s calibration data (PowerDiGi2 DB.pdb). After that, I could do a soft reset again and record a new calibration.
The image below shows some grids I made in Note Pad using a ruler and my stylus, the first one using Palm’s calibration, the three other ones using PowerDigi (and its three calibration modes):
As you can see, not a single line is exactly straight. This may be because of little inexactnesses during the calibration. But this is not a problem. I have used my Palm with enabled PowerDigi for some days now, and all my screen problems are gone. I can tap all buttons, even the small ones which appear in some programs. And also drawing detailed sketches is no problem anymore. When I draw a line and (later) want to continue it, I just need draw a new line starting on the old line’s end. Without PowerDigi, I couldn’t exactly reach the end of the old line – my Palm started drawing 2 mms above it.
In my opinion, PowerDigi is a must-have for all Palms with a screen that has calibration problems. Working with a decalibrated screen can be very annoying (I did it for more than one year now). According to the developer, it supports almost all Palms with OS5.x. The included install instruction manual mentions 25 different devices, but there may be support for other ones. So I recommend testing the program before buying. If it works on your device and you buy it, your screen problems should be solved. The $16.95 may sound a little bit expensive – but I think they are cheaper than buying a new digitizer. PowerDigi at Palmpowerups.
I must also praise the support for the program. Dmitry Grinberg was immediately availible on Google’s chat and could answer my questions about PowerDigi. He told me that he also offers support via e-mail, Yahoo, MSN and via phone.