Digi XB3-C-A2-UT series, Руководство пользователя, Страница: 64 / 151

Hardware RSSI PWM
Digi XBee3 Cellular LTE-M Global Smart Modem User Guide 64
Pin Name Direction Default Description
18 AD2 / DIO2 / SPI_CLK Either Disabled Analog Input 2 or Digital I/O
2, SPI Clock line
19
AD1 / DIO1 / SPI_ATTN
Either Disabled
Analog Input 1 or Digital I/O
1, SPI Attention line output
20 AD0 / DIO0 Either Input Analog Input 0, Digital I/O 0
Pin connection recommendations
The recommended minimum pin connections are VCC, GND, DIN, DOUT, RTS, DTR and RESET.
Firmware updates require access to these pins.
RSSI PWM
The XBee Smart Modem features an RSSI/PWM pin (pin 6) that, if enabled, adjusts the PWM output to
indicate the signal strength of the cellular connection. Use
P0 (DIO10/PWM0 Configuration) to enable
the RSSI pulse width modulation (PWM) output on the pin. If P0 is set to 1, the RSSI/PWM pin outputs a
PWM signal where the frequency is adjusted based on the received signal strength of the cellular
connection.
The RSSI/PWM output is enabled continuously unlike other XBee products where the output is enabled
for a short period of time after each received transmission. If running on the XBIB development board,
DIO10 is connected to the RSSI LEDs, which may be interpreted as follows:
PWM duty cycle
Number of LEDs turned
on
Received signal strength (dBm)
79.39% or more 3 -83 dBm or higher
62.42% to
79.39% 2 -93 to -83 dBm
45.45% to
62.42% 1 -103 to -93 dBm
Less than
45.45% 0
Less than -103 dBm, or no cellular network
connection
SIM card
The XBee Smart Modem uses a 4FF (Nano) size SIM card.
CAUTION! Never insert or remove SIM card while the power is on!