Nokia phone Arduino Shield

[charlespax]

I am making an Arduino shield to interface with old Nokia phones. I'd like to keep the price around $20 for the shield, cables, and phone. If I can get some software help from the community, this will be great for interfacing projects with the internet.

For photos, code, and a detailed writeup please check out my post at http://paxinstruments.com/nokia-phone-arduino-shield/

• Should the shield be for a specific Arduino board or be configurable? The AltSoftwareSerial library uses specific pins for different Arduino boards.
• Is it fine to have the phone and serial-to-USB chip both connected to the Arduino RX/TX lines?
• Do we need the level shifters?
• Is there a better Nokia cable that also provides power?
• The Nokia 3100 needs a battery to run even with the power cable inserted. Is there a way around this?
• Is there a better target phone?

Thought you might be interested. Thanks :-)