I was looking around online and saw the gsrm module for the arduino and got to thinking... with an LCD screen, a few buttons, and the cell module, couldn't the arduino make an actual phone? I've see posts on how to send texts from the pc through arduino, but what about an actual portable cell phone?
Links thoughts and anything else appreciated
Digitizing voice and converting digital sound into analog sound requires additional hardware. The Arduino itself doesn't have the capabilities to do either, let alone both, with reasonable quality.
The GSM modules are intended for data service, not voice.
You could probably do what you want, but the Arduino is certainly not the right platform.
Digitizing voice and converting digital sound into analog sound requires additional hardware.
There is also a lot of digital signal processing that goes on in a mobile phone like echo cancellation, and the arduino is not up to that one task let alone the others.
I would 'think' that most of the GPRS shields could be used for this, you 'just' need to make the MMI (user interface) and communicate with the shield using the 'AT command set' interface they support.
Audio connections must be made directly to the audio in/outputs on the shield.
I have not tested to see if it actually works, but the GPRS shield from Seeedstudio (utilizing the SIM900 module) have audio jacks on the shield, so this might be a candidate to look into - but I have no doubt that there are more shields out there that can do the job.
As a side note (I have not looked into this) I would think that you would run out of memory before the MMI is final, at least if you use a Uno board.