FreeCalypso > hg > freecalypso-schem2
annotate venus/src/pinouts/74LVC2G125.pinout @ 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> |
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date | Thu, 02 Dec 2021 22:40:39 +0000 |
parents | 4c4eeacce681 |
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rev | line source |
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975b9b7ec712
Venus MCL: add 74LVC125A for Calypso UART inputs
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
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1 #pin name pin number |
975b9b7ec712
Venus MCL: add 74LVC125A for Calypso UART inputs
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
2 nOE:1 1 |
975b9b7ec712
Venus MCL: add 74LVC125A for Calypso UART inputs
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
3 A:1 2 |
45
4c4eeacce681
74LVC2G125 buffer for BL control captured at MCL level
Mychaela Falconia <falcon@freecalypso.org>
parents:
13
diff
changeset
|
4 Y:2 3 |
4c4eeacce681
74LVC2G125 buffer for BL control captured at MCL level
Mychaela Falconia <falcon@freecalypso.org>
parents:
13
diff
changeset
|
5 GND 4 |
13
975b9b7ec712
Venus MCL: add 74LVC125A for Calypso UART inputs
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
6 A:2 5 |
45
4c4eeacce681
74LVC2G125 buffer for BL control captured at MCL level
Mychaela Falconia <falcon@freecalypso.org>
parents:
13
diff
changeset
|
7 Y:1 6 |
4c4eeacce681
74LVC2G125 buffer for BL control captured at MCL level
Mychaela Falconia <falcon@freecalypso.org>
parents:
13
diff
changeset
|
8 nOE:2 7 |
4c4eeacce681
74LVC2G125 buffer for BL control captured at MCL level
Mychaela Falconia <falcon@freecalypso.org>
parents:
13
diff
changeset
|
9 Vcc 8 |