FreeCalypso > hg > freecalypso-schem2
view venus/doc/Keypad-layout @ 70:8bc2aa52fd23
manual RESET button new part: 260 g force, shorter actuator
One of the main envisioned use cases for FC Venus is field demonstration:
the board will be carried around, mounted on a sheet of acrylic or somesuch,
it will have a battery and an antenna connected, there will be a test SIM
with active service inserted, and the setup will be ready to demonstrate
as a working phone at a moment's notice. But when a demo is not actively
in progress, the fully assembled setup will be transported around in a big
and loose ESD bag, and it will need to be equivalent to a traditional phone
in its switched-off state: battery present, RTC keeping time, but not
switched on all the time.
Having a RESET button of the same keyswitch type as used for the regular
keypad and PWON would cause a problem for such field transport scenarios:
any spurious press of this button would cause a "misc boot" switch-on.
Short spurious presses of PWON are filtered out by the firmware (automatic
power-off if the button isn't held down long enough), but the same cannot
be done for super-low-level nTESTRESET. However, a button with significantly
greater operating force and a shorter actuator (not sticking out to the same
height as the regular keypad buttons) should be much safer.
| author | Mychaela Falconia <falcon@freecalypso.org> |
|---|---|
| date | Thu, 02 Dec 2021 22:40:39 +0000 |
| parents | 9de8e7a43160 |
| children |
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FreeCalypso Venus will have the same 21-button main keypad as on TI's D-Sample development platform, as seen in this photograph: https://www.freecalypso.org/members/falcon/pictures/D-Sample/pic1.jpeg Each of these 21 buttons forming the main keypad underneath the LCD will be an E-Switch TL3301 series SMT tactile switch, mounted directly on the top side of FC Venus board. The following reference designators are assigned to these 21 tactile switches: S401 [LS] S402 [^] S403 [RS] S404 [<-] S405 [.] S406 [->] S407 [Green] S408 [V] S409 [Red] S410 [1] S411 [2] S412 [3] S413 [4] S414 [5] S415 [6] S416 [7] S417 [8] S418 [9] S419 [*] S420 [0] S421 [#] The label in square brackets indicates logical function: * [Green] and [Red] are the green call key (traditionally called SEND) and the red power/hang-up key (traditionally called END). * [LS] and [RS] are the left and right "soft function" keys, above [Green] and [Red] and directly below the LCD. * S402, S404, S405, S406 and S408 form the 5-way navigation button group (S405 is "center"); their [] labels are an ASCII art attempt to depict navigation key directions. * S410 through S421 form the most traditional 12-button dial keypad. In addition to these 21 tactile switches forming the main keypad, there will be 3 additional tactile switches of the same type corresponding to the 3 side buttons on D-Sample: S422 Left side button: volume up S423 Left side button: volume down S424 Right side button, function unspecified S422 and S423 will need to be placed on the left side of our LCD; S424 will need to be placed to the right of our LCD. S409 will be connected between PWON and GND and thus exist outside of KBC/KBR matrix. Each of the remaining 23 keyswitches will short across a KBC/KBR pair. Calypso provides 5 KBC and 5 KBR lines, allowing for up to 25 keyswitches, thus enough for our 23. The choice of which KBC/KBR crosspoint should be used for which button position is up to the PCB layout engineer - the source file to be edited is src/periph/keypad.v.