Hi all,

I've now built a prototype of an 8 channel datalogger I'm designing =
(albiet with only three channels) and was wondering...
The datasheet on the DS1820 says typ 200 ms to do the temp to digital =
converstion but the datasheet on the DS18S20 says max 750 ms. A bit of a =
difference!!

I was planning on having 8 channels all with their own 1-wire bus off a =
PIC pin. (I think this is know as single legged?) I then tell each in =
turn to start their conversions, I then go back to the first and keep =
checking it until it is ready to send me data, then check each of the =
rest in turn, each should have had time to do their conversion and I get =
all my data back.

However with the DS18S20 it looks like I might struggle to get a 1Hz =
sampling rate of all 8 channels!
If I were to go down the route of analogue temp sensors and then A2D =
them on an appropriate PIC, would I achieve higher samples rates.=20

I guess in the real work the sensor isn't going to change temp that =
quickly but even 5Hz would be nice... the digital route has the =
advantage of noise protection over the analogue method and I'm not even =
sure of an anlogue sensor and the const comparison.

Any help appriciated,

Cheers

Kev/.

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