Post by thread:onewire

I'm trying to find the Schottky diodes used in the 12v real all circuit used to interface serial ports to Dallas one wire devices (Dallas app note 74). Its an ERA-82-004, and I can't find it, or a cross refrence anywhere. On a PIC related note: I've been designing a PIC based interface to the DS1820 temperature sensors for the last couple of weeks in my spare time. It has a 2k eeprom for serial number storage, max232 for rs232 interface, and uses a LP2950 to regulate the power from the RS-232's DTR and RTS lines. I was planning one producing these and selling them for about $60, including 2 sensors. The purpose was to take the load off the computer (and so that it would work under a multitasking enviornment like Linux or Win95). But I forgot something. I had read app note 74 a long time ago, and I knew that you could use the serial port to directly talk to the devices, but I forgot about it. No I know that my device really isn't needed, and that it can all be done in software on the host, with 4 diodes and a resistor. Needless to say - when you charge ahead on a project don't forget to do your research first. At least I hadn't gone so far as to get boards produced yet <G>. Brian --- Nexus Computing spam_OUTnexusTakeThisOuTeskimo.com http://www.eskimo.com/~nexus The Islet BBS FidoNet by PPP dialup (206)927-9219 Brian Lane embedded systems programmer KC7TYU