Sleep support
Sleep parameters
Digi XBee® 3 802.15.4 RF Module User Guide
125
ON_SLEEP goes high and CTS goes low each time the remote wakes, allowing for communication
initiated by the remote host if desired.
Cyclic Sleep with Pin Wake-up mode (SM = 5)
Use this mode to wake a sleeping remote device through either the RF interface or by asserting (low)
DTR/SLEEP_RQ for event-driven communications. The cyclic sleep mode works as described previously
with the addition of a pin-controlled wake-up at the remote device.
The DTR/SLEEP_RQ pin is level-triggered. The device wakes when a low is detected then sets CTS low
as soon as it is ready to transmit or receive. The device stays awake as long as DTR/SLEEP_RQ is low;
once DTR/SLEEP_RQ goes high the device returns to cyclic sleep operation. If DTR/SLEEP_RQ is
momentarily pulsed low, the minimum wake time is
even if DTR/SLEEP_RQ is
low for less time.
Once awake, any activity resets the
timer, so the device goes back to sleep
only after there is no RF activity for the duration of the timer.
MicroPython sleep with optional pin wake (SM = 6)
The MicroPython sleep option allows a user's MicroPython program to exclusively control the device's
sleep operation (with optional pin wake). For full details refer to the
Sleep parameters
The following AT commands are associated with the sleep modes. See the linked commands for the
parameter's description, range and default values.
n
n
n
n
DP (Disassociated Cyclic Sleep Period)
n
Sleep pins
The following table describes the three external device pins associated with sleep. See the
Module Hardware Reference Manual
for the pinout of your device.
Pin name
Description
DTR/SLEEP_
RQ
For
SM
=
1
, high puts the device to sleep and low wakes it up. For
SM
=
5
, a high to
low transition wakes the device until the pin transitions back to a high state.
SPI_SSEL
Alternative SLEEP_RQ line for devices operating in SPI. See
for
further information.
CTS
If
D7
=
1
, high indicates that the device is asleep and low indicates that it is awake
and ready to receive serial data.
ON_SLEEP
Low indicates that the device is asleep and high indicates that it is awake.
