Share PDU code between CoAP and BLE? about aiohomekit HOT 4 OPEN

I've never seen a fragmented payload. The largest response is the accessory database and it came in at 1108 bytes. We might have to wait for a device with multiple accessories or more services and characteristics to see what happens when it crosses ~1500 bytes. The Thread network fragments to ~100 bytes and the Border Router reassembles so maybe we would just get a big payload split across a few UDP packets...

I don't mind coding defensively on the decode, starting with 3 bytes & only decoding the length if present. Yeah, I'm not super happy with it, I was trying to find a way to decode multiple good PDUs that have an "invalid request" PDU in the middle & communicate that error condition back up among the good data. I thought I saw that behavior at some point though I can't find an example in my current dev log. Both the Home app and Nanoleaf app send multiple requests in a single payload which might be a difference to BLE?

from aiohomekit.

Yeah, you can't batch requests payloads with BLE. You have to know the right characteristic GATT endpoint to write to AND know the iid as well, so each PDU goes to a different GATT endpoint.

I guess if you have multiple PDU's in a single UDP packet the body length is actually mandatory? Otherwise how do you know if you've found a body or the next PDU payload. And it wouldn't make sense to have different behaviour for the last PDU in a payload.

from aiohomekit.

I could just stick with bytes | PDUStatus and synthesize a PDUStatus for the tid mismatch and bad control conditions. That's slightly less gross.

from aiohomekit.

I was wondering the same thing, maybe make the value outside the range of a u8 so it doesn't clash in future?

from aiohomekit.