Surj

Deva Seetharam

here is the initial design of Tuxphone. (since i don't know how to embed images in drupal pages, i have included it as an external link.)

the main components are:

1. Gumstix - this includes gumstix connex 400, cfstix and breakout-gs boards. cfstix is necessary since the main board may not have sufficient space to hold the application.
2. gm862 - this is the gm862-pcs module with cingular prepaid sim card.
3. LCD - this is HD44780U, a character LCD module. i am using a character lcd module since it is chip and uses less number of i/o pins than a graphic LCD module.
4. Keypad - a 4x4 Gray Hill keypad
5. Keypad encoder - this is MM74C922 key encoder chip. this chip provides a bcd coded value of the key pressed. it also has a nice data available interrupt.
6. Microphone - WM-64K, a small omnidirectional mic from Panasonic.
7. Speaker - EAS-4D02C0 from Panasonic. it is not as small as i would like it to be.

pls. let me know your comments/thoughts/suggestions/ideas.

thanks in advance,
deva seetharam