[Question] Writing Zigbee attribute value in Octet format (0x41)?

Developer Programs Writing Device Types
1

Heya all,

According to the documentation, zigbee.writeAttribute() doesn’t support octet format (0x41),

How does the SmartThings “st wattr” command expect the octet? with commas? a list? separated by commas? just the octet with spaces?

Example:
“st wattr 0x${device.deviceNetworkId} 1 0 0xFFF0 0x41 {octect_payload}”

where octect_payload might be:

  • 0xaa, 0x10, 0x05, 0x41, 0x47, 0x01, 0x01, 0x10, 0x01
  • [0xaa, 0x10, 0x05, 0x41, 0x47, 0x01, 0x01, 0x10, 0x01]
  • 0xaa 0x10 0x05 0x41 0x47 0x01 0x01 0x10 0x01
  • [0xaa 0x10 0x05 0x41 0x47 0x01 0x01 0x10 0x01]

Thanks!

2

There is a some older documentation at https://stdavedemo.readthedocs.io/en/latest/device-type-developers-guide/building-zigbee-device-handlers.html if that helps.

3

Hey Graham,

Thanks for that one, I do have it on my favorites as a good old source of info :stuck_out_tongue:

I can’t seem to find just one zigbee attribute in my devices with an octet value to see how it comes in the catchall. And I don’t wanna spend more money in either a CC2231 with Zigbee2Mqtt or the ConBee with DeConz just to see what’s there and find a octet value field :frowning: (Might be a good investment though if I’m gonna keep going the zigbee train :stuck_out_tongue: )

Maybe @nayelyz would know how the format is expected :slight_smile: ?

4

Hi, there! I’ve talked with our engineering team about your question, the suggestion is using zigbee.writeAttribute with DataType.pack. It would be something similar to:

zigbee.writeAttribute(cluster_id, attr_id, DataType.UINT16, DataType.pack(0xDEAD, DataType.UINT16))

0xDEAD would be the hole payload you receive in hex.

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5

Thanks @nayelyz! will give it a try :slight_smile:

6

Hey @nayelyz !

Sorry it took me a while to test this, I had to circumvent somehow the other problem first (that runEveryXXMinutes() no longer works).

Unfortunately it doesnt work,

doing this:

zigbee.writeAttribute(0x0000, 0xFFF0, DataType.UINT16, DataType.pack("0xaa, 0x80, 0x05, 0xd1, 0x47, 0x07, 0x01, 0x10, 0x01", DataType.STRING_OCTET))

gives the following error:

java.lang.IllegalArgumentException: Currently data type 65 is not supported @line 357 (refresh)

Packing the data doesn’t seem to do the trick, and it still doesnt make sense to me, why would I attempt to write in UINT16, if the expected type is STRING_OCTET? Or am I missing something from the example?

The docs do say that DataType.pack() ONLY supports STRING_CHAR for variable lengths types, so if STRING_OCTET is of variable length (which I guess it is), I don’t understand why engineering would recommend using the pack() method.

If the last comment I made is correct (pack() doesnt support STRING_OCTET), then I guess I have to go back to the original question, on how does “st wattr” expect a STRING_OCTET value? like this?:

st wattr 0x${device.deviceNetworkId} 1 0 0xFFF0 0x41 "0xaa, 0x80, 0x05, 0xd1, 0x47, 0x07, 0x01, 0x10, 0x01"

Thanks!

Edit 1: yup its definitely of variable length, by doing:

zigbee.readAttribute(0x0000, 0xFFF0, [mfgCode: 0x115F])
trace.log "Unknown cluster number ${descMap.cluster} with attribute Id ${descMap.attrId} has been detected with value ${descMap.value}"

I got:

trace Test 1: Unknown cluster number 0000 with attribute Id fff0 has been detected with value 00
warn Unhandled variable length attribute, assuming a single attribute.

So zigbee.writeAttribute() cannot be used, dataType.pack() cannot be used, and probably I’m stuck on using “st wattr”, but it bears the question again on how to properly pass a STRING_OCTET to it, and now with a specific mfgCode (as I haven’t seen/found an example of “st wattr” targeting a manufacturer specific cluster).

Edit 2:

Well, I found a hidden reference in a post of apr’ 2020 on hubitat, which theoretically this should work for the mfgCode, but not yet sure on the STRING_OCTET:

st wattr 0x${device.deviceNetworkId} endpoint cluster attribute datatype {data} mfgCode
7

Hi, @Chares :smiley:
Our enginnering dept. reviewed the information you gave and this is their feedback:

  • You’re right, the “pack” won’t work for STRING_OCTET, the suggestion now is as follows:
zigbee.writeAttribute(0x0000, 0xFFF0, DataType.STRING_OCTET, "09AA8005D14707011001")

Note: the 09 at the beginning is added because the STRING_OCTET data type defines the first byte as length. This is not necessary if the device already has a process to get this value.

  • If you want to keep using st wattr, the data portion would be { 09AA8005D14707011001 } as you mention in your last edit.
  • The mfgCode is only used when the command needs to be manufacturer-specific.
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8

Hey @nayelyz, thnkas for the answer :slight_smile:

Unfortunately as mentioned earlier zigbee.* doesn’t support variable lenghts except for STRING_CHAR, that’s why my insistance on using “st wattr” though considered ‘legacy’, unfortunately zigbee.* doesnt yet support all dataTypes :frowning:

Thanks for the example! (that now makes more sense, no 0x in the string, all concatenated, and most likely in little Endian).

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