i would use a dallas ds1621, connected over i2c. so you don't have any influence from the line length. you need a 4 wire cable, and when clocking the i2c very slow, you have about no wirelenght limitation. (use serial resistors of about 470ohms on the sda and scl at each i2c chip to reduce edge peaks) Rick Mann Gesendet von: pic microcontroller discussion list 15.01.02 23:42 Bitte antworten an pic microcontroller discussion list An: PICLIST@MITVMA.MIT.EDU Kopie: Thema: [EE]: Good way to make a remote temp sensor? My application requires a remote temperature sensor, accurate to a degree F or better. I need to be able to place a temp probe 2 to 3 meters away from the controller. I was thinking of using an LM34DZ with a three-wire cable (and sealing up the sensor in some heat shrink), then I saw a post about the LM335, (which reads degrees K), and I decided that made more sense (it avoids the need for a negative Vref). However, the LM335 is a two-terminal device (plus the adjust), and requires a current source. The app note shows a generalized current source (can I just use a resistor?). And the trimmer pot looks like it should be near the sensor; is that necessary? Or can it be on the board? If anyone has any other suggestions for a variable-voltage-output sensor to operate in the room temperature range, I'd appreciate it. Thanks! --Rick -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu