Re: xPL...1 Wire

[steve.cooper@xxxx]

> Yep. I would think the 1-wire bridge PIC would have to:

> 1) Maintain a table (in eeprom?) of ROM IDs, and a ZONE number for
each
one
> 2) Poll each 1-wire device on the bus
> 3) Report the status of each zone
> 4) handle different 1-wire devices, switches, temperature etc.

Come into this a bit late on but in answer to your points

1) No need to, the best way to achieve zoning is to use DS2409 that have a
main and aux line. You can switch on individual DS2409's either main or
aux so that part of the 1-wire network is exposed to the master. You just
put all the devices for each zone on the main line and put a 1-wire memory
chip on the aux line with the zone name programmed into it. When you want
info for a particular zone you just switch on that DS2409 which will
disable all the other DS2409 for other zones then switch on the aux line
read the zone name then switch over to the main line and read the various
1-wire devices.

2) Easy enough to do the device id includes a device family code which
tells you if it's a temperature sensor, memory, iButton type etc. So you
know what to do with it. In a zoning example you would just search the
1-wire network for DS2409's that way when you plug in a new zone with a new
name it just picks it up automatically.

3) & 4) See above the way I would see a 1-wire to xPL network
working is
that you could specific up front that the topology must be zoned with all
devices hanging off of DS2409s. You could then start by releasing a
temperature sensor xPL master board then later upgrade the software so it
would report other 1-wire device either via a new board or just a program
upgrade. Once you start supporting two many different devices you may find
you outgrow a PIC chip though. As an example I have some code that will do
a full 1-wire search and report ID back that is about 1200 bytes.

S.






___________________________________________________________________________

The information contained in this message is confidential and may be
legally privileged. If you are not the intended recipient, please do not
read, copy or otherwise use it and do not disclose it to anyone else.
Please notify the sender of the delivery error and then delete the
message from your system.

Any views or opinions expressed in this email are those of the author only.

Communications will be monitored regularly to improve our service and for
security and regulatory purposes.

Thank you for your assistance.

___________________________________________________________________________