How does the device receive messages from the parent node when it goes into low power?

RE: How does the device receive messages from the parent node when it goes into low power?

liisa — Wed, 28 May 2025 00:33:16 GMT

Hi,

Thank you for your reply,I will try.

this is my config in prj.config:

#
# Copyright (c) 2024 Nordic Semiconductor
#
# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
#

# Increase Settings storage size
CONFIG_PM_PARTITION_SIZE_SETTINGS_STORAGE=0x8000


# Enable OpenThread CoAP support API
CONFIG_OPENTHREAD_COAP=y
CONFIG_COAP=y
CONFIG_COAP_UTILS=y
CONFIG_OPENTHREAD_COAP_OBSERVE=y

# Network sockets
CONFIG_NET_SOCKETS=y
CONFIG_POSIX_API=y
CONFIG_NET_SOCKETS_POLL_MAX=4

# Enable OpenThread features set
CONFIG_NET_L2_OPENTHREAD=y

# Generic networking options
CONFIG_NETWORKING=y

CONFIG_OPENTHREAD_JOINER=y

CONFIG_LOG=y

CONFIG_DK_LIBRARY=y

# Power Manager
CONFIG_PM_DEVICE=y

CONFIG_OPENTHREAD_MTD=y
CONFIG_OPENTHREAD_MTD_SED=y

CONFIG_OPENTHREAD_POLL_PERIOD=5000

CONFIG_RAM_POWER_DOWN_LIBRARY=y

#SHA
CONFIG_MBEDTLS_SHA1_C=n

RE: How does the device receive messages from the parent node when it goes into low power?

Sigurd — Tue, 27 May 2025 14:01:56 GMT

Hi!

Amanda is out of office, so I'm replying instead.

[quote user="liisa"]"send commands" is the leader send "coap get + ipv6 address + /lock/state".the "process" is the SED receive the "send commands" to return the lock's state.I mean, it doesn't feel like the SED device is going to automatically fetch the parent {"Data Poll" to its parent, and retrieves any buffered frames}.[/quote]

It is automatic process - the SED device needs to be configured with given Polling Interval (e.g. 2 seconds). Internally OpenThread stack will wake up every e.g. 2 seconds and fetch the data from the parent. There is no need for application to do specific things. Of course, application needs to register proper application callbacks for CoAP or UDP Sockets to get notification about reception of IPv6 application packet.

You may try to increase log's verbosity and maybe sniff frames.

CONFIG_OPENTHREAD_SOURCES=y
CONFIG_OPENTHREAD_DEBUG=y
CONFIG_OPENTHREAD_LOG_LEVEL_INFO=y
CONFIG_OPENTHREAD_SHELL=y

RE: How does the device receive messages from the parent node when it goes into low power?

liisa — Mon, 26 May 2025 03:34:24 GMT

Hi,Amanda H

"send commands" is the leader send "coap get + ipv6 address + /lock/state".the "process" is the SED receive the "send commands" to return the lock's state.I mean, it doesn't feel like the SED device is going to automatically fetch the parent {"Data Poll" to its parent, and retrieves any buffered frames}.

Regards,

liisa

RE: How does the device receive messages from the parent node when it goes into low power?

Amanda Hsieh — Fri, 23 May 2025 15:35:10 GMT

We would need more details about what you mean by "send commands", and what you expect to "process" from the SED side.

RE: How does the device receive messages from the parent node when it goes into low power?

liisa — Fri, 23 May 2025 06:05:39 GMT

Hi，

I'm using the cli example as the leader. When my SED device goes into low power, my leader send commands to SED, but I don't see any processing from the SED device.

Regards，

liisa.

RE: How does the device receive messages from the parent node when it goes into low power?

Amanda Hsieh — Wed, 21 May 2025 20:54:13 GMT

Hi,

Not sure if I understand the question. When you configure OpenThread as a Sleepy End Device (SED), the stack automatically wakes up every Polling Interval, and sends a 802.15.4 “Data Poll” to its parent, and retrieves any buffered frames. Your application doesn’t need to do anything special

I would need to know more details about what you want to help.

Regards,
Amanda H.