Hi John,

I found it:

http://8052.com/forum/rea...p;top=4333

But there is no way, to deal with it.
Since the most important functions are missing: WRBYT, RDBYTS
Also it seems only made for a defined crystal (11MHz ?)
and a defined port pin.

My routine can be used with crystals in the range of 8MHz ... 25MHz.
Also interrupts allowed.


The DS1820 looks nice to use more devices on the same wire.
But they are unfortunately many more expensive, than the DS1821.
Also it need a serial number detection phase.

Since 8 byte per device needed to store the serial number, an AT89S8252 looks nice to use its 2kByte EEPROM for this.


Peter