Particle Monitor One, Manual

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47 RTC_BAT RTC/Watchdog b. Connect to GND if not using.
48 RTC_EXTI RTC EXTI. Can use as a wake button. Has 100K weak pull-up to 3V3.
Pins 9 and 10 have NFC in the name from the Tracker SoM, however NFC cannot be used on the
Monitor One as the pins must be used as
VIN_EN and PERIPH_INT .
The GPIO pins on the expansion connector have the following specifications, from the nRF52840
datasheet:
Symbol Parameter Min Typ Max Unit
VIH Input high voltage 0.7 xVDD VDD V
VIL Input low voltage VSS 0.3 xVDD V
VOH,SD Output high voltage, standard drive, 0.5 mA, VDD ≥1.7 VDD - 0.4 VDD V
VOH,HDH Output high voltage, high drive, 5 mA, VDD >= 2.7 V VDD - 0.4 VDD V
VOH,HDL Output high voltage, high drive, 3 mA, VDD >= 1.7 V VDD - 0.4 VDD V
VOL,SD Output low voltage, standard drive, 0.5 mA, VDD ≥1.7 VSS VSS + 0.4 V
VOL,HDH Output low voltage, high drive, 5 mA, VDD >= 2.7 V VSS VSS + 0.4 V
VOL,HDL Output low voltage, high drive,3 mA, VDD >= 1.7 V VSS VSS + 0.4 V
IOL,SD Current at VSS+0.4 V, output set low, standard drive, VDD≥1.7 1 2 4 mA
IOL,HDH Current at VSS+0.4 V, output set low, high drive, VDD >= 2.7V 6 10 15 mA
IOL,HDL Current at VSS+0.4 V, output set low, high drive, VDD >= 1.7V 3 mA
IOH,SD Current at VDD-0.4 V, output set high, standard drive, VDD≥1.7 1 2 4 mA
IOH,HDH Current at VDD-0.4 V, output set high, high drive, VDD >= 2.7V 6 9 14 mA
IOH,HDL Current at VDD-0.4 V, output set high, high drive, VDD >= 1.7V 3 mA
RPU Pull-up resistance 11 13 16 kΩ
RPD Pull-down resistance 11 13 16 kΩ
GPIO default to standard drive (2mA) but can be reconfigured to high drive (9mA) in Device OS
2.0.0 and later using the
pinSetDriveStrength() function.
Be careful when you are connecting GPIO or ports such as serial that may have power when the
Monitor One is not powered, such as when using shipping mode.
If you have current flowing into GPIO or ports of the nRF52840 when it is powered down, it can
cause it to enter a state where it cannot be reawaked without removing all power from it, including
the internal LiPo battery. This may be difficult if you've sealed your Monitor One enclosure.
The Tracker One has a TI TS3A5018 Quad SPDT Analog Switch on the three GPIO pins (A3,
D9/RX/SDA, D8/TX/SCL) to prevent this. The switch is normally open, and is closed when the
CAN_5V
is powered. By default, Tracker Edge enables
CAN_5V
when in normal operating mode and
turns it off during sleep, however this behavior can be changed by using
enableIoCanPower()
and
enableIoCanPowerSleep()
in the
TrackerConfiguration
object.
The Tracker One circuit looks like this, and you may want to implement something similar if you
are in a scenario where you have externally powered peripherals.
I/O CHARACTERISTICS
GPIO AND PORT LEAKAGE CURRENT WARNING