Can I wake the sleepy endpoint using AT command?
No, the serial ports do not run in sleep mode. To bring the endpoint out of sleep mode you need to set the SLEEP_RQ pin low.
What happens if you try to add a device using the DE command and a device trips that is already learned? Does it take up another slot in memory?
No it will not take another slot. When an endpont is added, whether through the DE (discover endpoint) command or manually using the AE (add endpoint) command, if the endpoint already exists it will not be duplicated.
In order to save power, can the coordinator send a PL command over the air to each endpoint?
No this is not a way to remotely change the power level. Also, we do not allow coordinators to dynamically change the listen window for endpoints. The reason for this is that a sleepy endpoint is typically battery powered and dynamically extending ...
Does the coordinator need to have its sleep mode enabled to send queued packets to sleepy endpoints?
No and you typically don’t want to put the coordinator into sleep mode. When the queue packet command is used the coordinator will check to see if the endpoint is sleepy, and if it is not then it will send the message immediately. In other words, the ...
If I only used AT sleep mode command without SLEEP_RQ, coordinator still receives STA 0001, is this behavior right?
The sleep mode command ATSM will enable or disable sleep mode, but does not put the device to sleep. If an endpoint has sleep mode enabled but it is not sleeping then the coordinator should not receive the STA 0001 (sleepy endpoint) status message.
If you have a message queued for a sleepy endpoint that has not gone out yet, and you want to change that message, can you?
The next firmware release v1.02 will have a CQ (Clear Queue) AT command for this purpose.