User Manual
6.1.5 Power Button
A power button is connected to the input of the
TPS65217C
. This is a momentary switch,
the same type of switch used for reset and boot selection on the board.
If you push the button the
TPS65217C
will send an interrupt to the processor. It is up to
the processor to then pull the
PMIC_POWER_EN
pin low at the correct time to power
down the board. At this point, the PMIC is still active, assuming that the power input was
not removed. Pressing the power button will cause the board to power up again if the
processor puts the board in the power off mode.
In power off mode, the RTC rail is still active, keeping the RTC powered and running off the
main power input. If you remove that power, then the RTC will not be powered. You also
have the option of using the battery holes on the board to connect a battery if desired as
discussed in the next section.
If you push and hold the button for greater than 8 seconds, the PMIC will power down. But
you must release the button when the power LED turns off. Holding the button past that
point will cause the board to power cycle.
6.1.6 Battery Access Pads
Four pads are provided on the board to allow access to the battery pins on the
TPS65217C
.
The pads can be loaded with a 4x4 header or you may just wire a battery into the pads. In
addition they could provide access via a cape if desired. The four signals are listed below in
Table 2
.
Table 2 element14
BeagleBone Black Battery Pins
P
IN
DE
S
I
G
N
A
TION
F
U
N
C
T
ION
BAT
TP5 Battery connection point.
S
ENSE
TP6 Battery voltage sense input, connect to BAT directly at
the
b
a
t
t
e
r
y
te
r
m
i
n
a
l.
TS
TP7 Temperature sense input. Connect to NTC thermistor to
sense
b
a
t
t
e
r
y
temp
e
r
a
tur
e
.
G
ND
TP8
S
y
stem
g
roun
d
.
There is no fuel gauge function provide by the
TPS65217C
. That would need to be added if
that function was required. Access to 1-wire SPI, or I2C interfaces required to use a fuel
gauge will need to be accessed by using the expansion headers on the board.
NOTE: Refer to the TPS65217C documentation before
connecting anything to these pins.