Thanks for the reply Tony

Up until now I've been using a single 1wire device and the ccs c compiler.
I can read, write, get its address and do a crc on the data.

Now, I want to talk to multiple devices.  I have added  3 devices on the
bus to experiment with. I want to read the serial number of each at power
up and then individually address them. The problem is getting their serial
numbers(addresses)

I've read and re-read the dallas datasheet 187 '1 wire search algorithm',
but can't get the code to work, I'm sure this is a hole in my understanding
not in the dallas example code, but I can't help thinking theres a 'neater'
ie shorter, quicker way of doing it.

Regards

Steve

Tony Nixon wrote:

> Tony Nixon wrote:
>
> I forgot to mention that this will only work for 1 device on the bus at
> a time. There is a much more complicated procedure to use if multiple
> devices are on the bus and need identification, but I haven't used that
> method yet.
>
> > This is in assembler, but perhaps you can port it to C without much
> > bother.
> >
> > Data in buffer after execution = 8 bytes
> >
> > Family Code - 1 byte
> > ID Number   - 6 bytes
> > CRC         - 1 Byte
> >
> >         movlw Buffer            ; set buffer pointer
> >         movwf FSR
> >         call INITDS             ; start new transaction
> >         Send_Out Read_ROM       ; read ROM command
> > GIDLoop call IN_BYTE            ; read bytes
> >         movwf INDF
> >         incf FSR
> >         movlw Buffer + d'8'
> >         xorwf FSR,W
> >         btfss STATUS,Z
> >         goto GIDLoop
> >         return
>
> --
> Best regards
>
> Tony
>
> mICros
> http://www.bubblesoftonline.com
> mailto:sales@bubblesoftonline.com
>
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