One thing that might be useful is two way communication between the coordinator and end devices. In a serial console on the server or a command line program, you should be able to send a command to and end device and get a response. Here's how it could work:

python weatherbox-console.py

Enter your command here: ACKREQ 8888
...
Reply from node 8888: 
OK

Enter your command here: ACKREQ 9999
...
Reply from node 9999 timeout.

Enter your command here:

Note this is a communication layer that exists on top of the zigbee/xbee layer.

why it might be useful

It might be useful for a couple of things like:

• Checking that the firmware is in a good state (if it responds to a request from the coordinator, it's probably okay)
• Remotely setting the RTC
• Tell the box to stop transmitting
• Ask for the current GPS coordinates (to update the box's location information somewhere)
• Change the node id (not sure how often this is needed).
• Turn on power conservation mode

There could be more things, but in general, if there's some state that needs to be managed then it might be useful to have the ability to do them remotely. These things are easily accomplished with the command mode through serial, but it can be a pain once there are dozens/hundreds of nodes everywhere.

required work

• There would be some work needed to define the commands needed and the packet schema
• The firmware needs to be able to read incoming api frames from the xbee, determine it's a RX frame, and parse it to see it has command information and figure out what to do with it
• The gateway needs to handle these types of packets somehow
• The gateway needs to be modified to allow outgoing packets (it doesn't have any logic for that right now)

implementation notes

It would be good to start with something simple, like an ACKREQ command that once the node receives it responds with an OK or something. Other features can be built on top of this once the system is proven to work.

There is currently a staging gateway in use in the lab that is attached to a raspberry pi, this feature should be tested on that prior to rolling out to the production systems.

Contributing authors:

Created by kluong on 2021/03/25 17:37.