[OpenTRV-dev] ID length

[Bo Herrmannsen]

hmm bits and bytes...

could it be 4 digits and a group id?

just in case someone close by should have picked the same id etc?



-----Oprindelig meddelelse----- 
From: Damon Hart-Davis
Sent: Wednesday, April 30, 2014 10:31 PM
To: Closed list for developer discussions
Subject: [OpenTRV-dev] ID length

Hi,

I’m adding a locally-generated random ID to each node, to be used as an ID 
(or part of one) when there is not something more specific such as an FHT8V 
house code set.

In fact it’s designed so that each byte is in the range 0x80 to 0xfe so that 
it is not confusable with a house code (each byte in the range 0 to 99) or 
an unprogrammed EEPROM byte (0xff).

But, I’m wondering how big the ID should be.  An obvious size is 2 bytes to 
match a house code (and be longer than a JeeNode ID for example), but 
remembering Amdahl’s comment about running out of address bits being the 
really difficult thing to get round, and wanting avoid collisions even in 
larger establishments, I wonder if I should have (say) 4 bytes.  I don’t 
necessarily have to transmit/use all the ID bytes/bits in all circumstances.

Any thoughts?

Rgds

Damon
_______________________________________________
OpenTRV-dev mailing list
EMAIL ADDRESS HIDDEN
http://lists.opentrv.org.uk/listinfo/opentrv-dev