Apr.29 Buttons clean-up

Buttons: 2 1 4     each button is a bit.

                     8

Pressing 2 Buttons

• Our eCos/lms only supports pressing 1 button.
• and the raw button value is not available to user.
• Usually button 1 = enter (orange) + another button is supported.

Changes needed:

• eCos avr_cntl add function to return the raw button value
• will allow a user to add support for 2 buttons pressed via a FB as an exercise
• add OR of states and test values for at least Button 1+ another button