one wire

[Acetronics2]

Hi, Karen

1) Go here :

http://www.maxim-ic.com/products/ibu...tmex/index.cfm

download the soft corresp. to you system ...

2) Download the dS2480 Datasheet ... and get one or two of them ( think to the SAMPLES !!! )

3) Give me a PM mail where I can send you the Scheme, PCB and parts placement.

OR

Build THAT ...

http://www.elektor.de/jahrgang/2008/...e.497315.lynkx

You'll be able to read the Device IDs ...

OR

Just read your Datasheet ...

READ ROM [33h]
This command can only be used when there is one slave on the bus. It allows the bus master to read the
slave’s 64-bit ROM code without using the Search ROM procedure. If this command is used when there
is more than one slave present on the bus, a data collision will occur when all the slaves attempt to
respond at the same time.

64-BIT LASERED ROM CODE
Each DS18B20 contains a unique 64–bit code (see Figure 6) stored in ROM. The least significant 8 bits
of the ROM code contain the DS18B20’s 1-Wire family code: 28h. The next 48 bits contain a unique
serial number. The most significant 8 bits contain a cyclic redundancy check (CRC) byte that is
calculated from the first 56 bits of the ROM code. A detailed explanation of the CRC bits is provided in
the CRC GENERATION section. The 64-bit ROM code and associated ROM function control logic allow
the DS18B20 to operate as a 1-Wire device using the protocol detailed in the 1-WIRE BUS SYSTEM
section of this datasheet.
64-BIT LASERED ROM CODE Figure 6
8-BIT CRC 48-BIT SERIAL NUMBER 8-BIT FAMILY CODE (28h)
MSB LSB MSB LSB MSB LSB

and buid a little application just to read the ID ...

Something more ???

Alain

[karenhornby]

Totally perfect thanks
not sure if I'll buy the usb adaptor or just make the interface yet but really good info and exactly what I was looking for
I would just make an interface but it's going to take a few weeks for samples or orders to get from US to UK so might be easier just to buy the usb one made up
especially as they are srface mount devices and I cant guarantee my hand or eyes are good enough to work with them