The easiest way I've found this is to use the Wavefront Accelerometer Data Application , which can be found on the App Store. All you have to do is add one file to the application, then you can use the accelerometer on your iPhone or iPod touch to send data to your application in the simulator. You will need a WiFi connection and a device to use.
You may find a solution that works on your desktop, but you won’t get accurate real-life readings.
I would recommend getting the actual device, or your application may behave differently than you expect. If this is a serious attempt, you should be able to justify the cost of the device. The iPod Touch is much cheaper, but you don't get the capabilities of a phone or camera. You can get a headset with a microphone.
These are limitations, I do not consider it appropriate to develop the application without testing it on the device. I came across applications that constantly crash and draw it, because they go away with things in the simulator that you cannot do in the memory and restrictions on the device’s device.
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