acassis commented on code in PR #18368: URL: https://github.com/apache/nuttx/pull/18368#discussion_r2782079676
########## Documentation/components/drivers/character/input/keypad-keyboard.rst: ########## @@ -0,0 +1,142 @@ +======================= +Keyboard/Keypad Drivers +======================= + +**Keypads vs. Keyboards** Keyboards and keypads are really the +same devices for NuttX. A keypad is thought of as simply a +keyboard with fewer keys. + +**Special Commands**. In NuttX, a keyboard/keypad driver is simply +a character driver that may have an (optional) encoding/decoding +layer on the data returned by the character driver. A keyboard may +return simple text data (alphabetic, numeric, and punctuation) or +control characters (enter, control-C, etc.) when a key is pressed. +We can think about this the "normal" keyboard data stream. +However, in addition, most keyboards support actions that cannot +be represented as text or control data. Such actions include +things like cursor controls (home, up arrow, page down, etc.), +editing functions (insert, delete, etc.), volume controls, (mute, +volume up, etc.) and other special functions. In this case, some +special encoding may be required to multiplex the normal text data +and special command key press data streams. + +**Key Press and Release Events** Sometimes the time that a key is +released is needed by applications as well. Thus, in addition to +normal and special key press events, it may also be necessary to +encode normal and special key release events. + +**Encoding/Decoding** Layer. An optional encoding/decoding layer +can be used with the basic character driver to encode the keyboard +events into the text data stream. The function interfaces that +comprise that encoding/decoding layer are defined in the header +file ``include/nuttx/input/kbd_code.h``. These functions provide +an matched set of (a) driver encoding interfaces, and (b) Review Comment: ```suggestion a matched set of (a) driver encoding interfaces, and (b) -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
