Thread

Overview #

  • some elements have link to the corresponding websites

Cheat sheet #

  • IPv6 bit length : 128 bit = 8x 16 ibts => 00b1:00b2:00b3:00b4:00b5:00b6:00b7:00b8
  • Link-Local prefix : fe80::/16
  • Mesh-Local prefix : fd00::/8
  • Multicast Link-Local : ff02::1
  • Multicast Mesh-Local : ff03::1
  • RLOC16 : Routing locator in 16 bits 0x0401
  • RLOC16 Router mask : 0x0400
  • IID : Interface Identifier (includes RLOC16)
  • RLOC = Mesh-Local Prefix + IID

Specification #

Tools #

  • install nRF Connect for deskop
  • From within nRF connect, install Toolchain Manager
  • From the Toolchain manager, install the last nRF Connect SDK

Thread Nodes #

A Thread network setup contains the following Nodes

  • radio or network coprocessor : dongle connected to the raspberry pi

  • border router host : services running on a raspberry pi

  • cli tester : command line dongle through serial monitor for testing

  • mqtt-sn : end device with mqtt-sn such as sensors

  • Topology Monitor : GUI interface. Note the hex file to flash on the nRF52840 USB dongle are provided as part of the download pack in nRF_TTM-win32-x64_0.13.0.zip\nRF_TTM-win32-x64\hex. A different CLI or NCP fimware would not work.

  • Wireshark sniffer : dongle that captures all frames and shows them on wireshark

Border Router #

To create a border router, a usb dongle needs to be flashed (Radio Co-Processor) and attached to a raspberry pi where the following services are installed.

raspberry pi #

install git if not already available

git clone https://github.com/openthread/ot-br-posix
cd ot-br-posix
export NAT64=1 NAT64_SERVICE=openthread
./script/bootstrap
INFRA_IF_NAME=eth0 ./script/setup
sudo nano /etc/default/otbr-agent
sudo reboot now
sudo systemctl status
sudo ot-ctl state
  • issue: in case a dnsmasq service already running, might have to be disabled first
  • issue: in case of not being able to create a network (not advertising on wireshark) a new raspi install might be required as network adapters conflicts might prevent the otber-agent from running properly

the /etc/default/otbr-agent service config file should be configured with the right adapter

# Default settings for otbr-agent. This file is sourced by systemd
# Options to pass to otbr-agent
OTBR_AGENT_OPTS="-I wpan0 -B eth0 spinel+hdlc+uart:///dev/ttyACM0"

The status of the running services look as follows. These services should now be available :

  • avahi-daemon
  • otbr-agent : access the usb device and creates wpan0
  • otbr-web : creates the OTBorderRouter web server
  • wpa_supplicant
    sudo systemctl status
    pi@metal:~ $ sudo systemctl status
    ● metal
        State: running
         Jobs: 0 queued
       Failed: 0 units
        Since: Thu 1970-01-01 01:00:01 CET; 51 years 1 months ago
       CGroup: /
               ├─user.slice
               │ └─user-1000.slice
               │   ├─session-3.scope
               │   │ ├─1663 sshd: pi [priv]
               │   │ ├─1669 sshd: pi@pts/0
               │   │ ├─1670 -bash
               │   │ ├─1687 sudo systemctl status
               │   │ ├─1688 systemctl status
               │   │ └─1689 pager
               │   ├─user@1000.service
               │   │ └─init.scope
               │   │   ├─1637 /lib/systemd/systemd --user
               │   │   └─1638 (sd-pam)
               │   └─session-1.scope
               │     ├─ 864 /bin/login -f
               │     └─1648 -bash
               ├─init.scope
               │ └─1 /sbin/init splash
               └─system.slice
                 ├─ncp_state_notifier.service
                 │ ├─427 /bin/sh /usr/sbin/ncp_state_notifier
                 │ ├─432 dbus-monitor --system type='signal', interface=org.freedesktop.DBus.Properties, path
                 │ └─433 /bin/sh /usr/sbin/ncp_state_notifier
                 ├─alsa-state.service
                 │ └─395 /usr/sbin/alsactl -E HOME=/run/alsa -s -n 19 -c rdaemon
                 ├─containerd.service
                 │ └─553 /usr/bin/containerd
                 ├─systemd-timesyncd.service
                 │ └─341 /lib/systemd/systemd-timesyncd
                 ├─NetworkManager.service
                 │ ├─420 /usr/sbin/NetworkManager --no-daemon
                 │ └─633 /sbin/dhclient -d -q -sf /usr/lib/NetworkManager/nm-dhcp-helper -pf /run/dhclient-et
                 ├─dbus.service
                 │ └─409 /usr/bin/dbus-daemon --system --address=systemd: --nofork --nopidfile --systemd-acti
                 ├─hciuart.service
                 │ └─826 /usr/bin/hciattach /dev/serial1 bcm43xx 3000000 flow -
                 ├─udisks2.service
                 │ └─394 /usr/lib/udisks2/udisksd
                 ├─docker.service
                 │ └─853 /usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock
                 ├─ssh.service
                 │ └─564 /usr/sbin/sshd -D
                 ├─ser2net.service
                 │ └─868 /usr/sbin/ser2net -c /etc/ser2net.conf -P /run/ser2net.pid
                 ├─avahi-daemon.service
                 │ ├─393 avahi-daemon: running [metal.local]
                 │ └─398 avahi-daemon: chroot helper
                 ├─otbr-web.service
                 │ └─428 /usr/sbin/otbr-web
                 ├─wpa_supplicant.service
                 │ └─419 /sbin/wpa_supplicant -u -s -O /run/wpa_supplicant
                 ├─triggerhappy.service
                 │ └─442 /usr/sbin/thd --triggers /etc/triggerhappy/triggers.d/ --socket /run/thd.socket --us
                 ├─systemd-logind.service
                 │ └─439 /lib/systemd/systemd-logind
                 ├─polkit.service
                 │ └─511 /usr/lib/policykit-1/polkitd --no-debug
                 ├─otbr-agent.service
                 │ └─423 /usr/sbin/otbr-agent -I wpan0 spinel+hdlc+uart:///dev/ttyACM0
                 ├─telegraf.service
                 │ └─542 /usr/bin/telegraf -config /etc/telegraf/telegraf.conf -config-directory /etc/telegra
                 ├─cron.service
                 │ └─437 /usr/sbin/cron -f
                 ├─systemd-udevd.service
                 │ └─181 /lib/systemd/systemd-udevd
                 ├─rsyslog.service
                 │ └─403 /usr/sbin/rsyslogd -n -iNONE
                 ├─bluetooth.service
                 │ └─831 /usr/lib/bluetooth/bluetoothd
                 ├─inetd.service
                 │ └─857 /usr/sbin/inetd
                 ├─bluealsa.service
                 │ └─834 /usr/bin/bluealsa
                 ├─systemd-journald.service
                 │ └─121 /lib/systemd/systemd-journald
                 ├─bind9.service
                 │ └─560 /usr/sbin/named -u bind
                 ├─rng-tools.service
                 │ └─415 /usr/sbin/rngd -r /dev/hwrng
                 └─dhcpcd.service
                   └─473 /sbin/dhcpcd -q -b
    

After forming a network, the interface would look as follows

ifconfig wpan0
wpan0: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST>  mtu 1280
        inet6 fd85:454:6529:a0c5:9ebb:d761:b6d:df4e  prefixlen 64  scopeid 0x0<global>
        inet6 fd11:22::7005:5eac:6482:e2ec  prefixlen 64  scopeid 0x0<global>
        inet6 fe80::94bf:4de7:183c:f37d  prefixlen 64  scopeid 0x20<link>
        inet6 fd85:454:6529:a0c5:0:ff:fe00:fc00  prefixlen 64  scopeid 0x0<global>
        inet6 fd85:454:6529:a0c5:0:ff:fe00:d400  prefixlen 64  scopeid 0x0<global>
        unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 500  (UNSPEC)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 9  bytes 1524 (1.4 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

Radio Co-Processor (RCP) #

Using a deprecated version of RCP not matching the raspberry pi installed otbr-agent version will prevent it from running
  • build and flash the Radio coprocessor using the build target nrf52840dongle_nrf52840
cd nrf/samples/openthread/coprocessor
west build -b nrf52840dongle_nrf52840 -- -DCONF_FILE="overlay-usb.conf" -DOVERLAY_CONFIG="usb.overlay"
  • place the dongle in bootloader mode by pressing the reset button and plug it in USB
  • flash the file nrf\samples\openthread\coprocessor\build\zephyr\zephyr.hex

udp test #

Note that for networking tests, a border router installation is recommended or network between docker and the host has to be configured.

The openthread-setup should be performed to be able to install and use socat. Listening from ot-ctl :

$sudo ot-ctl
>udp open
>udp bind :: 4242

note that the port will be freed from bind when closing the ot-ctl command line
Listening using socat:

$socat UDP6-LISTEN:4242,fork STDOUT

Multicast on link local

>ot udp open
>ot udp send ff02::1 4242 hi_there_now

Multicast on mesh local

>ot udp open
>ot udp send ff03::1 4242 hi_there_now

Form a network #

  • on the raspi command line
sudo ot-ctl dataset init new

sudo ot-ctl dataset channel 24
sudo ot-ctl dataset channel
sudo ot-ctl dataset panid 0x1234
sudo ot-ctl dataset panid
sudo ot-ctl dataset networkname ThreadMatter
sudo ot-ctl dataset networkname
sudo ot-ctl dataset extpanid 1111111122222222
sudo ot-ctl dataset networkkey 00112233445566778899aabbccddeeff
sudo ot-ctl dataset

sudo ot-ctl dataset commit active

sudo ot-ctl ifconfig up
sudo ot-ctl thread start
  • check with
sudo ot-ctl state
sudo ot-ctl netdata show
sudo ot-ctl ipaddr
  • on the web interface

connect on the raspberry pi url http://10.0.0.41/

  • on the left menu click on Join then select the required paramters (e.g. Channel,…) then click on FORM

wireshark sniffing #

  • git clone https://github.com/NordicSemiconductor/nRF-Sniffer-for-802.15.4
  • Folow the user guide especially section Installing the nRF Sniffer capture plugin in Wireshark
    • Flash the nrf802154_sniffer_dongle.hex
    • configure the used masterkeys in wireshark menu Edit/Preferences then Protocols/IEEE 802.15.4 in Decryption Keys Edit...
    • enter Decryption key, Decryption key index set to 0, and key hash to Thread hash

When Forming a network, some Pakets can be sniffed including advertisment

MQTT Sensors Node #

  • MQTT-SN is a protocol not requiring Thread necessarily, it is rather a protcol for a bridge that allows clients to interact with an MQTT Broquer with minimal payload and packets transfers, therefore, it is well adapted to ip over low power mesh networks such as Thread.

  • Example firmware mqttsn_sleepy_publisher and mqttsn_client_publisher are a port of the nRFSDK example from PCA10056 which was the only supported board to the PCA10059, the nRF52840 USB dongle, therefore the search gateway, connect, publish sequence have been merged in on button and run cyclically on each new press.

useful commands

sudo systemctl status paho-mqttsn-gateway.service
sudo /usr/sbin/MQTT-SNGateway -f /etc/paho-mqtt-sn-gateway.conf
sudo nano /etc/paho-mqtt-sn-gateway.conf
paho-mqtt-sn-gateway.conf
#**************************************************************************
# Copyright (c) 2016-2019, Tomoaki Yamaguchi
#
# All rights reserved. This program and the accompanying materials
# are made available under the terms of the Eclipse Public License v1.0
# and Eclipse Distribution License v1.0 which accompany this distribution.
#
# The Eclipse Public License is available at
#    http://www.eclipse.org/legal/epl-v10.html
# and the Eclipse Distribution License is available at
#   http://www.eclipse.org/org/documents/edl-v10.php.
#***************************************************************************
#
# config file of MQTT-SN Gateway
#

# IPv4 Address of iot.eclipse.org
BrokerName=10.0.0.42
BrokerPortNo=1883
BrokerSecurePortNo=8883

#
# When AggregatingGateway=YES or ClientAuthentication=YES,
# All clients must be specified by the ClientList File
#

ClientAuthentication=NO
AggregatingGateway=NO
QoS-1=NO
Forwarder=NO

#ClientsList=/path/to/your_clients.conf

PredefinedTopic=NO
#PredefinedTopicList=/path/to/your_predefinedTopic.conf

#RootCAfile=/etc/ssl/certs/ca-certificates.crt
#RootCApath=/etc/ssl/certs/
#CertsFile=/path/to/certKey.pem
#PrivateKey=/path/to/privateKey.pem

GatewayID=1
GatewayName=PahoGateway-01
KeepAlive=900
#LoginID=your_ID
#Password=your_Password


# UDP
GatewayPortNo=10000
MulticastIP=225.1.1.1
MulticastPortNo=1883

# GatewayUDP6Broadcast address is set to all Thread devices address
# in order to enable Thread Sleepy Devices to receive multicast messages
# sent from the gateway.
# UDP6
GatewayUDP6Port = 47193
GatewayUDP6Broadcast = ff03::1
GatewayUDP6If = wpan0

# XBee
Baudrate=38400
SerialDevice=/dev/ttyUSB0
ApiMode=2

# LOG
ShearedMemory=NO;

Test vector for sending a SEARCHGW message to the MQTT-SQ gateway service

#send (Length 3)(MsgType SEARCHGW=1)(Radius 1)
echo -n -e "030101" | xxd -r -p | nc -u fd11:1111:1122:0:98bf:60c7:9431:ee90 47193

Firmware flow diagram #

running the firmware example mqtt_client_publisher results in the following logs

MQTT-SN gateway log
pi@raspberrypi:~ $ sudo /usr/sbin/MQTT-SNGateway -f /etc/paho-mqtt-sn-gateway.conf
ClientList can not open the Predefined Topic List.     /etc/predefinedTopic.conf

 ***************************************************************************
 * MQTT-SN Transparent Gateway
 * Part of Project Paho in Eclipse
 * (http://git.eclipse.org/c/paho/org.eclipse.paho.mqtt-sn.embedded-c.git/)
 *
 * Author : Tomoaki YAMAGUCHI
 * Version: 1.3.1
 ***************************************************************************

20210213 194529.539 PahoGateway-01 has been started.

 ConfigFile: /etc/paho-mqtt-sn-gateway.conf
 SensorN/W:   Gateway Port: 47193 Broadcast Address: ff03::1 Interface: wpan0
 Broker:     10.0.0.42 : 1883, 8883
 RootCApath: (null)
 RootCAfile: (null)
 CertKey:    (null)
 PrivateKey: (null)



20210213 194535.931   SEARCHGW          <---  Client                              03 01 01
20210213 194535.932   GWINFO            --->  Clients                             03 02 01

20210213 194541.989   CONNECT           <---  nRF52840_publisher                  18 04 04 01 00 3C 6E 52 46 35 32 38 34 30 5F 70 75 62 6C 69 73 68 65 72
20210213 194541.997   CONNECT           ===>  nRF52840_publisher                  10 1E 00 04 4D 51 54 54 04 02 00 3C 00 12 6E 52 46 35 32 38 34 30 5F 70 75 62 6C 69 73 68 65 72
20210213 194542.042   CONNACK           <===  nRF52840_publisher                  20 02 00 00
20210213 194542.042   CONNACK           --->  nRF52840_publisher                  03 05 00

20210213 194542.055   REGISTER    0001  <---  nRF52840_publisher                  1D 0A 00 00 00 01 6E 52 46 35 32 38 34 30 5F 72 65 73 6F 75 72 63 65 73 2F 6C 65 64 33
20210213 194542.056   REGACK      0001  --->  nRF52840_publisher                  07 0B 00 01 00 01 00

20210213 194550.331   PUBLISH     0002  <---  nRF52840_publisher                  08 0C 20 00 01 00 02 01
20210213 194550.331   PUBLISH     0002  ===>  nRF52840_publisher                  32 1C 00 17 6E 52 46 35 32 38 34 30 5F 72 65 73 6F 75 72 63 65 73 2F 6C 65 64 33 00 02 01
20210213 194550.338   PUBACK      0002  <===  nRF52840_publisher                  40 02 00 02
20210213 194550.338   PUBACK      0002  --->  nRF52840_publisher                  07 0D 00 01 00 02 00

20210213 194557.499   PUBLISH     0003  <---  nRF52840_publisher                  08 0C 20 00 01 00 03 00
20210213 194557.500   PUBLISH     0003  ===>  nRF52840_publisher                  32 1C 00 17 6E 52 46 35 32 38 34 30 5F 72 65 73 6F 75 72 63 65 73 2F 6C 65 64 33 00 03 00
20210213 194557.515   PUBACK      0003  <===  nRF52840_publisher                  40 02 00 03
20210213 194557.516   PUBACK      0003  --->  nRF52840_publisher                  07 0D 00 01 00 03 00

20210213 194602.541   PUBLISH     0004  <---  nRF52840_publisher                  08 0C 20 00 01 00 04 01
20210213 194602.542   PUBLISH     0004  ===>  nRF52840_publisher                  32 1C 00 17 6E 52 46 35 32 38 34 30 5F 72 65 73 6F 75 72 63 65 73 2F 6C 65 64 33 00 04 01
20210213 194602.547   PUBACK      0004  <===  nRF52840_publisher                  40 02 00 04
20210213 194602.547   PUBACK      0004  --->  nRF52840_publisher                  07 0D 00 01 00 04 00
Firmware J-Link RTT log
<info> app_timer: RTC: initialized.
<info> app: Thread version   : OPENTHREAD/20191113-00534-gc6a258e3; NRF52840; Apr  5 2020 21:53:43
<info> app: Network name     : OpenThreadDemo
<info> app: Thread interface has been enabled.
<info> app: 802.15.4 Channel : 13
<info> app: 802.15.4 PAN ID  : 0x1234
<info> app: Radio mode       : rx-on-when-idle
<warning> app_timer: RTC instance already initialized.
<info> app: State changed! Flags: 0x0117D33D Current role: 1
<info> app: State changed! <info> app: (0)
<info> app: MQTT-SN event: Client has found an active gateway.
<info> app: MQTT-SN event: Client has found an active gateway.
<info> app: MQTT-SN event: Gateway discovery procedure has finished.
<info> app: MQTT-SN event: Gateway discovery result: 0x0.
<info> app: (1)
<info> app: Wake up first time
<info> app: MQTT-SN event: Client connected.
<info> app: MQTT-SN event: Client registered topic.
<info> app: MQTT-SN event: Topic has been registered with ID: 1.
<info> app: (2)
<info> app: Wake up next times
<info> app: MQTT-SN event: Client has successfully published content.
<info> app: (2)
<info> app: Wake up next times
<info> app: MQTT-SN event: Client has successfully published content.
<info> app: (2)
<info> app: Wake up next times
<info> app: MQTT-SN event: Client has successfully published content.

Firmware search gateway #

Building on other frameworks #

Platformio #

  • although Zephyr is integrated in platformio, openthread is unfortunately not yet supported as of framework-zephyr 2.20400.201210 (2.4.0)
  • docs.platformio limitations

Arduino #

  • in discussion in this openthread issue#1803, the issue is that Arduino lacks the netwroking layers required to provide a descent interface to the app.

Build with Matter Node #

As the Matter Protocol can run over Thread, it is possible to connect Matter applications.

Command Line Interface #

cli on border router #

in this case the dongle is flashed with ot-rcp.hex not with ot-cli.hex

sudo ot-ctl state
sudo ot-ctl
>

cli dongle #

  • building with openthread repo
cd ~/ot-nrf528xx
./script/bootstrap
./bootstrap
sudo rm -rf build/
./script/build nrf52840 USB_trans -DOT_COMMISSIONER=ON -DOT_JOINER=ON -DOT_THREAD_VERSION=1.2
cd build/bin/
arm-none-eabi-objcopy -O ihex ot-cli-ftd ot-cli-ftd-com-join.hex

nrfjprog -f nrf52 --eraseall
nrfjprog -f nrf52 --program ot-cli-ftd.hex --sectorerase --verify
  • building with nRFSDK
cd nrf\v2.3.0\nrf\samples\openthread\cli
>west build -p always -b nrf52840dongle_nrf52840 -- -DOVERLAY_CONFIG="overlay-usb.conf" -DDTC_OVERLAY_FILE="usb.overlay"
>nrfutil pkg generate --hw-version 52 --sd-req=0x00 --application build/zephyr/zephyr.hex --application-version 1 build/zephyr/zephyr.zip
nrfutil dfu usb-serial -pkg build/zephyr/zephyr.zip -p COM8

then on terminal laways preceed with ot for openthread commands

uart:~$ ot state
disabled
Done
  • connecting a node with credentials
panid 0x1234
panid
channel 24
channel
networkname OpenThreadDemo
networkname
extpanid 1111111122222222
masterkey
ifconfig up
thread start
state

Note masterkey command is for the Network Key

at this stage the state command should log child

wireshark should log the join as follows

  • it’s possible to ping with the router ip
>ping fe80::c85c:d0c4:1103:31d5
Done
> 16 bytes from fe80:0:0:0:c85c:d0c4:1103:31d5: icmp_seq=2 hlim=64 time=12ms

cli reference #

various commands

cu -l /dev/ttyACM0 -s 115200
panid 0xabcd
ifconfig up
thread start
state
ping fd00:0064:0123:4567::0808:0808
router list

debug adresses

panid
rloc16
eui64
extaddr
extpanid
ipaddr
ipmaddr
leaderdata

ntwrok debug

scan
child list
child table
childip

Commissioning #

note that the security concept is based on the confidentiality of the networkkey (previously known as masterkey), the one used here is a dummy key used for demo purpose only. Setting a predefined masterkey is optional, the stack will generate a random one that can be retrieved with the networkkey command if it’s needed for analysis purpose.

For clarity purpose, it is assumed that the commissioner has already joined the network (see previous section), and in this case we will run commissionning directly on the raspberry pi border router with sudo ot-ctl which will clearly differentiace from the joiner that only needs ot

summary #

on the commissionner

sudo ot-ctl commissioner start
sudo ot-ctl commissioner joiner add '*' ABCDE2

on the joiner

ot ifconfig up
ot joiner start ABCDE2

details #

then on the commissioner cli who is already attached to the network, run

sudo ot-ctl commissioner start
sudo ot-ctl commissioner joiner add '*' ABCDE2

or preferrably with the eui64 of the joining device that you can get from the device, note the eui64 is always the same and unique for every device, cannot be changed (unlexx code is modified) as it is inherited from the device serial number registers. So it is not changed through factory reset.

>ot eui64
f4ce36594b6e559b
Done

then run the followinf commands on the commissioner. Note it’s important to do this before the joiner attempt

sudo ot-ctl commissioner start
sudo ot-ctl commissioner joiner add f4ce36594b6e559b ABCDE2

on the joiner cli run these commands, note that factoryreset might restart the target so you might have to connect the serial console again. Note that factoryreset is not needed unless the device was already attached to another network.

ot factoryreset
ot ifconfig up
ot joiner start ABCDE2

this should log Done and Join success but it will only store the newly obtained credential and will not join the network, for joining the network it’s possible to run any time

ot ifconfig up
ot thread start
commissioner and joiner logs
  • commissioner log
> commissioner start
Commissioner: petitioning
Done
> Commissioner: active

> commissioner joiner add * ABCDE2
Done
> ~ Discovery Request from 76380f6b58cf89f6: version=3,joiner=1
Commissioner: Joiner start a320c9053f0862ce
Commissioner: Joiner connect a320c9053f0862ce
Commissioner: Joiner finalize a320c9053f0862ce
Commissioner: Joiner end a320c9053f0862ce
  • joiner log
> joiner start ABCDE2
Done
> Join success
  • wireshark sniffing should display among others the following transactions
    • MLE : Discovery Request
    • MLE : Discovery Response
    • DTLSv1.2 : Client Hello
    • DTLSv1.2 : Hello Verify Request
    • DTLSv1.2 : Server Hello, Server Key Exchange, Server Hello Done
    • DTLSv1.2 : Client Key Exchange, Change Cipher Spec, Encrypted Handshake Message

Thread UDP packets #

  • Thread UDP packets are encapsulated using 6LoWPAN which has a payload of 88 Bytes, that’s why such a json UDP text message
thread_tags/7009D837C7BB557A{"alive":18673,"voltage":3.106,"light":184.948,"temperature":24.56,"humidity":46.49,"pressure":961.90}

is split in two packets where each has an ACK. From one side that’s a lot x4 times of what the RF power consumption could be for a simple broadcast, but at the same time it avoids taking care of manually adapting the program behaviour to accomodate the protocol. Also keeping a json text format instead of binary avoids a middle layer converting binary to text readable by apps, that would cost a bottleneck dependency between each device and the gateway.

FAQ - Discussion #

What is the difference between RCP/NCP Thread Stack ?
RCP stands for Radio Co-Processor and only includes the MAC Layer not the full Thread Core stack. More details : https://openthread.io/platforms#network-co-processor-ncp
What is the link between FTD/ETD Thread Devices ?
FTD = Full Thread device can be a Thread router or more, an ETD End Thread Device can be M:minial or S:Sleepy and in both cases does not route packets. More details https://openthread.io/guides/thread-primer/node-roles-and-types
What is the difference between using an RCP/NCP and running Thread as a stand alone device ?
The difference only lays on the partitioning of the application, in the RCP/NCP the application runs on the Host be it a raspberry pi or another uC, in the stand alone the whole thread stack and app run on the same device. We can think of the NCP as example like the CLI=command line interface Thread utility, but the protocol is not text mode rather binary. If the host is an uC itself, the question would be, why using two uC and if it is possible rather to merge them in just one, a corner case might need that like for example a double uC with WiFi and thread capabiltiy.
Does the Thread Topolog Monitor use the same CLI firmware as the openthread CLI ?
No, the Thread Topology monitor TTM comes with it own firmware that needs to be flashed
How does the Thread Topolog Monitor work ? What can it see ?
The Thread Topolog Monitor TTM is an active node on the network, it needs the credentials to be able to join it and only then it can retrieve info from the network it will also display itself in the network.
What is the difference between the Thread Topology Monitor and the 802.15.4 sniffer ?
The 802.15.4 sniffer does not join the network and is totally passive. It can listen to all the traffic of the channel it is in, including all pan ids. If it has the master key, it can then decript data from the corresponding network.
can I run openthread with Arduino ?
No, at least not at the moment and not within a native integration similar to the wifi and network in arduino. Despite being known to be an IDE, under the hoods, Arduino is also a framework. The current preferred and supported framework for openthread is Zephyr-OS.
can I run openthread with platformio ?
This is under investigation and should be available soon. The current platformio integration of Zephyr-OS does not include openthread, but this is likely to change any time soon.
Which other families than nRF from Nordic support Thread ?
Many platforms are supported including but not limited to Cascoda, NXP, Qorvo which extends to uwb variant, Samsung, Silicon Labs, STMicroelectronics, Synopsys, Telink Semiconductors, TI more details on openthread platforms. Note that Espressif although listed in the platforms, does not support 802.15.4 therefore can only run the openthread stack as a host that requires an external RCP from the previous list.
How does the joiner get to know on which channel is the commissioner's network running if it knows nothing about the network parameters ?
The joiner scans all frequencies until it gets a response from a commissioner. Given that the joiner might be low power, this operation is to be minimized and the commissionner is always ready and listening.