Zigbee Pairing + Payload Conversion to JSON

1

Hi Team,

Thanks for your effort and help. I have two questions please:

  1. Imagine we have the CC2531 running with firmware CC2531ZNP-Prod (as coordinator). CC2531 is plugged in and zigbee2mqtt is not not running/not installed. Will the CC2531 come up as a coordinator and will I be able to pair devices? The reason for the question is, that I would like to find out is if the Zigbee network is created/maintained by the hardware (firmware) only or does it need zigbee2mqtt to actually run in order to even start the the coordinator function of the CC2531 and the zigbee network. I know that in the configuration you can provide PAN ID, keys, channel. Those are optional and there is a certain default value, which is already known (default) in the firmware of the CC2531 or does it need to be provided by a software (in this case zigbee2mqtt) to bring up the coordinator functionality of the CC2531.

  2. When e.g. a button is pressed, the button will send a Zigbee message. We will see something like that:

MQTT publish: topic ‘zigbee2mqtt/CONTACT_SENSOR’, payload ‘{“contact”:true,“tamper”:false,“battery_low”:false,“linkquality”:0}’

This represents the MQTT publish, topic and payload. In the Zigbee packet there is an ID which we can identify the device with. How is the payload in the actual Zigbee packet receives encoded? I am sure this is different depending on the vendor. I doubt the Zigbee payload is this JSON string "{“contact”:true,“tamper”:false,“battery_low”:false,“linkquality”:0}? My understanding is that zigbee2MQTT is creating this readable JSON string based on the proprietary (vendor dependent) encoding of the sensor data which is encoded in the Zigbee payload. Are those “raw Zigbee payload values” documented somewhere? Is it possible to print/log this? Is it possible to capture the RAW Zigbee data of the CC2531 with while it is running as a coordinator? I know there is a separate firmware which allows to capture with wireshark (but I assume with this firmware the stick does not run as coordinator).

Thanks for your answer. I appreciate your time.

Best regards,
Robert