Serial Interface for 1-Wire Bus

The 1-Wire devices from Dallas Semiconductor are components that via a simple serial connection can be connected to each other, a circuit or a computer. The RS232-interface described here makes the connection to a PC very straightforward. In addition, Dallas supplies the necessary software free of charge.The 1-Wire series from Dallas already has received attention on earlier occasions in this magazine, such as the E-key project in November 2000 and the 1-Wire Spy in February 2001. In those projects the communication between the 1-wire bus and the PC was controlled by a microcontroller which was specifically programmed for this purpose. Dallas itself also manufactures ICs that deal with interfacing to microcontrollers or PCs. Drivers, evaluation and development software are available for free and may be downloaded from the Dallas web site.

Resistors:
R1 = 4kOhm 7
Capacitors:
C1 = 10µ F 25V radial
C2,C3 = 100nF
Semiconductors:
D1,D2 = BAT85
D3 = zener diode 4.7V 400 mW
D4,D5 = DS9503 (6-pin TSOC)
IC1 = DS2480BS (8-pin SOIC)
IC2 = 78L05
Miscellaneous:
K1 = 9-way sub-D- socket (female), angled pins, PCB mount
PCB, order code 020022-1