Android Emulator vs Real Device
I am aware of these limitations:
- Pre-installed software. Real device can have preinstalled a lot more applications than emulator.
- You cannot use "capture" photo/video functions in emulator.
According to emulator documentation, its limitations are:
The functional limitations of the emulator include:
No support for placing or receiving actual phone calls. You can simulate phone calls (placed and received) through the emulator console, however.
No support for USB connections
- No support for device-attached headphones
- No support for determining network connected state
- No support for determining battery charge level and AC charging state
- No support for determining SD card insert/eject
- No support for Bluetooth
IMO you can use emulator to simplify UI development, to view UI on "device screen", to be sure that app layout is ok, app can be run, you can test some special cases by simulating gps position, network speed or messaging etc. But testing on real device is a must.
With the 1.5 SDK the following limitations exists (from the SDK website):
- No support for placing or receiving actual phone calls. You can simulate phone calls placed and received) through the emulator console, however.
- No support for USB connections
- No support for camera/video capture (input).
- No support for device-attached headphones
- No support for determining connected state
- No support for determining battery charge level and AC charging state
- No support for determining SD card insertion/removal
- No support for Bluetooth
- No support for Multitouch
Based on experience I've noticed the following differences in actual developemnt:
- There are bugs you'll be able to ignore in the emulator that will crash the device (not closing Cursors for example)
- You interact with the device differently than the emulator. I use landscape mode a lot more with the real device than I do with the emulator.
- There's a different CPU. Things that are fast on your emulator will be slower on the real device.
- You can dogfood with the device. It is harder to dogfood with the emulator.
There is a google group here if you need real device testers.
One cannot test touch events with emulator which has to be tested only by means of mouse clicks on emulator which any developer going to develop an application based on touch screens should be aware of.
I'd say the main thing is that there are several "real devices" currently using Android, and there will be more, with different hardware endowments -- some will have GPS and some won't, ditto for touchscreen, real keyboard as opposed to virtual on-screen one, camera resolution, etc, etc.
While the OS will do a lot of the heavy lifting for you, you still want to make sure your design a user experience that makes sense on every Android device you intend to support, despite the variation in their HW features -- in this sense, designing applications for Android is more similar to designing them for, say, Linux, Windows, or the Web (cater for a wide variety of hardware-configuration details), rather than e.g. Macs or iPhone (where you need to consider a much narrower set of possible HW configurations).
The emulator is (or tries to be;-) "one" Android device -- but there will be others ("real" ones;-) with different screen resolutions, input peripheral devices, etc, etc...